Pike’s Peak has been a cornerstone of advanced Chevy Volt developmental engineering. The road is so important to Volt development because it represents a continuous long grade uphill. This driving condition would be expected to put a maximum load on the Volt’s engine-generator while in charge sustaining mode. After the battery reserve is depleted, the roughly 3500 pound car has to rely solely on its 53 kw (71 hp) engine to deliver power for the continuous climb, sustained velocity, and any acceleration. Since the car will thus be at its performance limits, engineers can try to tweak the system to keep performance acceptably nimble. Indeed this scenario is exactly why the Mountain Mode was created; to give drivers an extra large battery buffer to dip into when an uphill grade arrives.
Every time GM has gone to Pike’s Peak we’ve been told the Volts perform well. Yet they keep going back, as refinement continues.
Recently Edmunds captured a fleet of Volts taking the climb and descent and posted the video below. Volt spokespersons Rob Peterson confided Volts have traveled altogether about 800 miles on Pike’s Peak. The path is 38 miles round-trip and the summit is at 14,110 feet. “At this point, our development engineers are focusing on real-world miles, putting the vehicles through their final paces,” said Peterson.
The ride back down form the summit is also interesting because the car can recapture a significant amount of energy via regenerative braking. “By the time the Volts made it off the hill, they had recaptured double-digit miles of energy,” said Peterson.
I asked Volt director Tony Posawatz, what GM is learning from its repeated trials up and down the Peak.
“As you know, we are very serious about the testing we do on our cars, especially the VOLT with it being loaded with so many “technology firsts,” he said. “We try to prove to ourselves that in the most severe and harshest environments that every VOLT will exceed our expectations including on-going “tweaks” as we finalize our software/controls and assure full completion of all of our tests.”
“It is pretty fun to continue to do work on Pikes Peak when you know your car can handle it,” said Posawatz. “Do all other plug-ins tout their prowess on Pikes Peak? I think not.”
“You know our ReGen braking recaptures a lot of electric miles on the way down and records a really low brake pad temp,” he added. Such low temperatures have occurred that a ranger who performs mandatory brake testing seven miles from the summit actually had to check the Volt twice with his laser gun.
Aug 20th, 2010 (6:34 am)Does anyone know the distances and elevation changes on the route they are taking?.. Pikes Road probably stresses many cars in the market.
GM may just be gathering summer vs winter data on a mountain road.. we all remember the picture of the Volt fleet on a snowy parking lot last winter, at Pikes Peak.
+13
Aug 20th, 2010 (6:35 am)This is one of the many reasons this car will be so successful. It is being tested and refined until it is the best vehicle it can be!!!
What will be as interesting will be when they get out on the road, and we start to get the reports from end users.
2011 will be a fun year at gm-volt.com
And then I can compare the 2012 model that I will be able to purchase in Ohio to see what else has been modified….
Good work GM Volt Team!!!!
NPNS
+1
Aug 20th, 2010 (6:37 am)Seriously, a radar detector on Pikes Peak? How fast you guys climbing?
+10
Aug 20th, 2010 (6:41 am)Impressive testing being done on the Volt. Appears brake service and oil changes will be an infrequent side stop. The Volt may well turn out to be a terrific vehicle for hilly regions. Electric motors have no issue with thin air or head gasket seals.
Have been following the testing on the Ampera as well. Reports of creamy power and triple digit MPG are being reported.
=D-Volt
+7
Aug 20th, 2010 (6:42 am)I assume when Lyle said laser gun he was referring to a hand held IR thermometer that can measure approximate surface temperature on the rotors.
+2
Aug 20th, 2010 (6:43 am)In the context of brake temperatures, I’m guessing it was actually an infrared sensor used by the rangers to determine if a car’s brakes are still safe for continued descent.
Doh. Nuclearboy had the same answer in a neck and neck posting race, haha.
+3
Aug 20th, 2010 (6:47 am)Not to mention no performance degradation of the electric motor at high altitude, like the ICE would experience.
-16
Aug 20th, 2010 (6:48 am)(click to show comment)
+13
Aug 20th, 2010 (6:53 am)Um.. Ya just did
+2
Aug 20th, 2010 (6:55 am)Interesting video, but, not so much explanation of what it is. Anytime a Volt is found in the wild it’s a good day.
+4
Aug 20th, 2010 (6:56 am)…whereas, I’m referring to the radar detector affixed to the front windshield in the video.
+1
Aug 20th, 2010 (6:57 am)This is a shot of UCSB located in Isla Vista California. The front range tops at 3985′. Great view of the Channel Islands from up there.
=D-Volt
+1
Aug 20th, 2010 (6:58 am)Just more proof that this is not your run-of-the mill EV, but a car that you can use just like you would use your conventional ICE-powered car.
Aug 20th, 2010 (7:07 am)Indeed. When that video hit the forums a day or two ago, the lack of description (both on Youtube and in the referencing articles) caused me to misunderstand completely. I thought it was supposed to be a view from the INSIDE of a Volt climbing Pike’s Peak. I didn’t even notice the “6 Volts” in the opposing traffic. When it rains, I guess I stop scrutinizing the car models around me
It’s great that GM is doing all this testing and refinement, but all this attention to the mountain climbing is probably just going to put the idea in people’s heads that “electric cars can’t climb long grades” or worse “electric cars have no power” (pun not intended). So GM better dream up some carefully crafted taglines to combat that.
Taglines that are better than “it’s more car than electric” that they’ve just unveiled on the Chevy Volt website.
Aug 20th, 2010 (7:11 am)Good point… Whats up with the radar detector??? Could GM engineers be speeding in some of their Volt testing?
PS. I can’t believe baltimore17 thought you must be referring to the brake temperature testing. What was he thinking???
+1
Aug 20th, 2010 (7:11 am)I can only say I have driven the Peak in a conventional car, and felt a mixture of both exhilaration and fear.
Hats off to these engineers/test drivers, and if it lives up to its promise, the car they have created for a very arduous journey.
+4
Aug 20th, 2010 (7:12 am)“By the time the Volts made it off the hill, they had recaptured double-digit miles of energy,”
Holy #$!#. That’s a lot more than I thought you could get.
+2
Aug 20th, 2010 (7:20 am)The car taking the picture (the one with the radar detector) is not a volt. He was only commenting on the use of a radar detector while climbing the peak.
Don’t worry Rooster – I got your comment!
Go Volt!!!!!!!!!
+3
Aug 20th, 2010 (7:25 am)The radar detector is actually in the Edmunds car. But that leads to the question, does Edmunds just have cars driving around 24/7 with cameras rolling in the hopes of coming across some type of new car testing!
I hope is because they were tipped off and somebody was taking a chance that they would drive past the VOLTs. Of course in the age of digital, I guess people can run the cameras 24/7 just in case something strange appears and then they can post it on youtube! 
+3
Aug 20th, 2010 (7:32 am)Are the grades really bad on Pike’s Peak? Do they limit any cars from going up it? I would still love to see the Volt go up Mt Washington, though I know Pike’s Peak is higher in elevation.
Maybe I’ll be the first Volt to do it. I finally got an order number yesterday, woo hoo!
join thE REVolution
+1
Aug 20th, 2010 (7:35 am)Lyle’s Posting:
“Volt spokespersons Rob Peterson confided Volts have traveled altogether about 800 miles on Pike’s Peak.”
LOL Lyle, if Rob “CONFIDED” he was hoping for confidentiality!
On the flip side Rob should know that anything he says will be on this site and not confidential for long! 
confided [past participle, past tense of con·fide (Verb)]
1. Tell someone about a secret or private matter while trusting them not to repeat it to others.
Great information and great to see the VOLT is the top technology for the future. The only other EV that could pull this off is the Tesla at $109,000. I suspect Edmunds won’t be posting any pictures of Leaf climbing Pikes Peak.
Aug 20th, 2010 (7:36 am)I think he was referring to the radar detector in the vehicle climbing the peak and taking video of the Volts descent. I grinned to myself when I saw the radar detector in the picture too.
join thE REVolution
+1
Aug 20th, 2010 (7:44 am)Was that in the Edmunds car?!? Heck, I was thinking GM was doing some “strategic communication” — in the Volt, you can spend all day climbing Pikes Peak, and still need a radar detector so you can make good time (75+ MPH) on the trip back to the hotel in Denver. Think a Leaf could do that?
+10
Aug 20th, 2010 (7:44 am)My guess is no Nissan Leaf’s will ever get near Pike’s Peak – so why ever test it there.
Wait – put a nissan-leaf on a truck and ship it to the foot of the mountain fully charged. Aim it just right and let her go – would it make it to the top? Does regen work backing up – if it doesn’t make it!!!
-4
Aug 20th, 2010 (7:45 am)I would guess the primary mission is to “blend in” the onset of power fade as well as tweaking the settings for mountain mode (i.e. how aggressively to run the genset). August temperatures in the stuffed engine bay will result in reduced efficiencies and increased loads. Hopefully the premium fuel will keep detonation away.
/Having that much regen coming back in on the way down could present it’s own set of problems as well.
+3
Aug 20th, 2010 (7:47 am)From the article
“We try to prove to ourselves that in the most severe and harshest environments that every VOLT will exceed our expectations including on-going “tweaks” as we finalize our software/controls and assure full completion of all of our tests.”
This is what I love about these guys. They test and retest on their way to making the most reliable car GM has ever made.
Good luck to all you early adopters. You are going to own one fine automobile.
+1
Aug 20th, 2010 (7:49 am)Actually I would very curious as to the Leaf’s performance. Would a full charge make it to the top? Wouild it get double-digit miles of regen on the way down?
+1
Aug 20th, 2010 (7:52 am)All this testing is great. One question I have is the vehicle weight. Lyle said the car weighs about 3500 pounds but I thought it was around 3900 pounds. Does anyone know the actual figure? Thanks in advance.
+2
Aug 20th, 2010 (7:53 am)Great job GM test test and more test !
Tom
Aug 20th, 2010 (8:31 am)The amount of regen power captured is primarily limited by the voltage range of the power electronics and the state of charge of the battery. The bigger the deltaV the more power you can dump into the battery. So, the energy captured would be the (average regen power) X (time to descend).
You’d only have to capture ~2kWh of energy to go “double digit” miles (10 miles worst case). That should be very easy on a 38 mile downhill grade.
Even if they only allow the battery to discharge to 50% SOC in mountain mode and only allow it to recharge to 80% SOC during regen… that would leave 4.8 kWh of available capacity in the battery (80% SOC – 50% SOC)…enough to go about 24 miles if that much energy could be captured during the descent.
+1
Aug 20th, 2010 (8:37 am)Very good question. If you assumed that the power electronics of the Volt and Leaf had the same limits (max/min voltage limits), then the battery with the lowest state of charge would be able to recapture the most energy during regen. braking.
In theory, the Leaf would be at a lower SOC than the Volt (if it could make it to the top). Therefore, the Leaf would have the potential to capture a higher kW # than the Volt on the way down…and thus earn back more kWh…which translates into greater miles.
+1
Aug 20th, 2010 (8:38 am)Testing and refining is all good. Still waiting for the CS MPG.
+4
Aug 20th, 2010 (8:39 am)That’s even MORE impressive, when you consider the downhill run is only about 19 miles…! Over 50% recovered energy? Holy cheese’n'crackers, Gromit!
Aug 20th, 2010 (8:43 am)That’s the purpose of the planetary gearset. It’s only function is during regen.
It maximizes regen efficiency!!
+2
Aug 20th, 2010 (8:44 am)Minor quibble, Jeremy, the story says (and I haven’t confirmed, sorry) that it’s 38 miles round-trip. Meaning, only 19 miles downhill.
+1
Aug 20th, 2010 (8:53 am)The grades ARE that bad. Add to that the switchbacks and no shoulders with shear-face drop-offs, and it makes for a heckuva drive.
I remember when I was a kid, my dad drove our family up Pikes Peak in the family station wagon. We wanted to go up the day before, but a school bus had slid off the road and tumbled down the mountainside a few hundred feet. Really bad scene: people dying, dozens of ambulances going up and down the mountain and the road closed for the day. We watched it all happen from the park entrance at the base of the mountain. The next day, the road was back open for business! While we were going up the mountain, my Mom in the front passenger seat was white knuckle all the way gripping the arm rest on her car door. Even then (this was the ’60′s) the ranger checked every cars brakes.
Its great the Chevy Volt can take you up Pikes Peak!
Aug 20th, 2010 (8:56 am)deleted by author
+1
Aug 20th, 2010 (8:56 am)Exciting and amazing that GM is still testing and perfecting this vehicle right up until launch date. Mountain mode was probably somewhat of an afterthought and they are trying to make sure that it’s ready. That’s the beauty of the software algorithm controlled engine. They can continue to tweak even after launch through ONStar.
Aug 20th, 2010 (9:00 am)Wonder why a number of Volts are sent up and down the mountain, rather than just one.
Aug 20th, 2010 (9:02 am)The Volt would have most certainly burned through all of its electricity (or close to it) by the time it hit the peak, which would give you 70% of the 16kWh battery to fill up, which is more than enough for the 19 mile descent worth of regen (which apparently yields between 10-19 miles worth of electricity regened).
+3
Aug 20th, 2010 (9:04 am)I kind of doubt this will happen. Updating your Windows automatically is one thing, since a Windows crash may be a pain, but a car crash can kill you.
I would suspect any changes to engine algorithms would require taking it to your local Chevy dealer.
+1
Aug 20th, 2010 (9:06 am)Maybe not as fast as Nobuhiro Tajima http://www.youtube.com/watch?v=G2y3OFf0ArU in the
Pikes Peak International Hill Climb http://www.usacracing.com/ppihc
+30
Aug 20th, 2010 (9:11 am)Once again, we get to marvel at a pack of these magnificent beasts as the camera captures the movements of a herd of wild VOLTs out in the open.
As they ascend, we see that they take the inclement weather and driving patterns of slower, old fashioned hybrids in stride, negotiating around these obstacles with grace and speed.
They arrive at the summit with energy to spare. As they pass our hidden observation post, they slow just enough to give us a friendly “chirp” from their pedestrian warning system, one of the few sounds ever heard from these eerily quiet creatures.
Their pace quickens as they begin the decent. One can almost feel their energy increase as their regenerative powers come into play.
Shortly after this, the pack of wild VOLTs fade into the distance, and we can only hope their destination is a local showroom for some lucky consumers.
+3
Aug 20th, 2010 (9:11 am)One reason might be to compare various software versions or various loads in the car. i.e. different mountain mode set points, charge levels, curb weight….
Aug 20th, 2010 (9:13 am)Great race to the top of the peak. Volt, leaf, and John1588321 or what ever his number is.
Aug 20th, 2010 (9:16 am)Yep, my bad….
50% recovery would mean that the energy gained going 19 miles downhill would get you 9.5 miles going back UP the hill. The kWhs consumed going up would be considerably more than 10 miles of flat land driving…
+1
Aug 20th, 2010 (9:18 am)It sounds like the VOLT generator is kicking in longer in mountain mode, as going up Pike Peak is using a lot of juice. It would be interesting to see if the Leaf could make it up the hill without draining the battery. The good news for Leaf is if it died, they could turn it around and going down hill it would recharge somewhat.
+1
Aug 20th, 2010 (9:21 am)I disagree. When in “mountain mode” the Volt does not let the SOC drop to 30% (correct me if I’m wrong). I believe mountain mode maintains a higher SOC to allow more battery reserve for hill climbing.
Even if we assume that both the Leaf and the Volt were at their minimum SOCs, the Leaf would have a greater deltaV for longer because it has a higher battery capacity. Assuming a hill of infinite length and starting with a drained battery, the Leaf will win every time.
To put it simply, the Leaf has more “potential” because it has a bigger battery.
Aug 20th, 2010 (9:26 am)Or use the controller to time the AC pulses to produce power from the drive motor when you lift off the go pedal? Or use a clutch to run MG1 backwards?
+1
Aug 20th, 2010 (9:26 am)Your assuming it made it do the top on electric power to recover 50%? I hardly doubt it. Even worse is if it was using the battery and the engines, because it is really using power/gas like mad, that is if you trying to express the recovery as a percent of usage. My understanding is that it had zero electric power in most of these tests and they were testing the extended range. No question it can get up the hill easy if it still has access to the battery.
I would like to know what the MPG is for a 70 hp 4 cylinder engine that is working as a electric generator while dragging a 3,500-3,900 pound car up Pike’s Peak is tho.
I think the double digit miles recovered is if you are once again driving it around on a flat surface at 50mph. If you turned that double digit electric range around and started from the bottom again, it probably gets you up about 2-3 miles.
Aug 20th, 2010 (9:31 am)[insert tongue in cheek]
Not only that, but in the event of a “Quantum Vacuum Collapse,” the Volt, the road, the mountain, and the Earth will all disappear; so obviously, the Volt program should be abandoned.
[remove tongue from cheek]
+1
Aug 20th, 2010 (9:32 am)My guess would be that one is in mountain mode, one is standard mode, one in sport mode, not sure if there are other modes. One thing to test for, esp. in mountain mode would be because SOC is kept higher, then what happens when regen threatens to take SOC over 100% on the downhill. If that can happen then regen needs to be turned off and the conventional brakes need to be completely relied on. I’m guessing that a lot of their testing has to do with a smooth transition from regen to conventional brakes (you don’t want an unexpected speed change/braking change when zipping downhill around a curve).
+5
Aug 20th, 2010 (9:34 am)Inspired, picturesque writing, CorvetteGuy! If I didn’t know better, I’d think you were describing a herd of mountain Elk (“wild Volts”) traversing the John Muir Trail somewhere between its highest point —Mount Whitney (14,505 ft) and its lowest point in the Yosemite Valley (4,035 feet)!
/ Help GM’s Ad agency out with this!
+1
Aug 20th, 2010 (9:34 am)Maybe the Volt could become the basis for an “Infinite Improbability Drive”.
+1
Aug 20th, 2010 (9:35 am)That’s adorable. Pike’s tops 14,000 ft. and we all live above 5000′ here.
Aug 20th, 2010 (9:37 am)I’m guessing that Carcus 3 would find this infinitely improbable.
Aug 20th, 2010 (9:40 am)Yes, but who wins uphill starting with a with a 30% SOC. Bummer trying to plug in that leaf a mile 15.
Aug 20th, 2010 (9:41 am)I’d be willing to bet that with all of GM’s testing they have recorded some very interesting gasoline useage statistics (notice that I did not say MPG). In this particular case, the total gasoline used in each vehicle would be appropriate, especially when compared to other vehicles under similar conditions. Hey Prius-John maybe you should set out for Pikes Peak! (seriously)
Aug 20th, 2010 (9:42 am)Pikes Peak highway; 19 miles long, 7400 ft elevation change. Good test. I once drove it in a 1982 Volkswagen Rabbit diesel years ago. It is quite steep near the top.
Aug 20th, 2010 (9:43 am)Yeah. I don’t know the height to the top from where you start, but assuming it’s at sea level, 1600Kg X 4000M X 9.8m/s2 = 62.72M Joules. In which case you’re looking at recapturing 17.84 kWh.
Double digits would be more than half. That would be better than I expected, but that estimate is probably too low since the drop has to be considerably less than I’m assuming. (Or my math is off since I haven’t had my coffee yet).
EDIT: Han has given the height from the base in #60 and it’s half what I used. So I’m not sure I can get double digit kWh from the descent. Have to go back and look at the math.
Aug 20th, 2010 (9:45 am)Interesting point. Have I fallen prey to a Jedi mind trick?
+4
Aug 20th, 2010 (9:47 am)Sample size
Aug 20th, 2010 (9:49 am)Even at less than 30% SOC or the customer depletion point, A new Volt will be at 8 KWh of a total of 16 kWh or an overall 50% SOC. New Volt will = greater DeltaV and higher resistance. Volt is optimized for long stable battery life, not fast charging.
Perhaps an older Volt using a greater percent of the battery could be programmed to accept more regen or fast charging opportunities. Li Ion’s have expected shelf life’s as well as expected cycles and GM has not posted their testing results for long term use. Double digit regen mileage from a 20 mile run seems pretty good as a back of the napkin calculation for new Gen I Volts.
+2
Aug 20th, 2010 (9:56 am)As a statistician, my guess is that they are using different cars and drivers to see what variations in drivers might affect the mountain mode. Different people will break and accelerate with different patterns. Ideally they would use everyday people rather than professional drivers or car engineers.
Aug 20th, 2010 (9:56 am)Just following up on #61, I’m with kdawg that double digits is HOLY #$!#. Only more so. Even using 4000 pounds and 2200 meters, you’re only looking at being able to recapture 10.78 kWh on the descent. Capturing double digits would be recovering over 90% of the energy, which frankly doesn’t strike me as believable given the unavoidable conversion losses.
I wonder what the average was? Or what techniques they used?
Aug 20th, 2010 (9:57 am)Or Ikuo Hanawa.
http://www.theautochannel.com/news/2010/07/01/485423.html
Still, you can’t expect a GM grunt in a bone stock production EREV to be able to compete with an expert driver in a one off tuned for a specific sprint race and conditions EV. The point here is that Pikes Peak is a good test area for tuning mountain mode and regen braking for real world EREV use. And it showcases what a really competent all around vehicle the Volt gen 1 is.
+1
Aug 20th, 2010 (10:04 am)I have no doubt that people will love regen. braking, especially going down steep grades. My wife loves using the B setting in our Prius which is similar to the L setting in the Volt when we travel down Mt. Lemon, 9000 ft. elevation. We still have original brakes at 110K miles. My wife use to wear out brakes faster then most people do.
Aug 20th, 2010 (10:16 am)They said double digit MILES right? I have to imagine they meant normal range double digit miles, like what the car would say given the charge of the pack. If 8kWh = 40miles, 2kW gives you 10 miles. That doesn’t seem unattainable IMHO.
That also doesn’t mean they didn’t use 20kWh to get up there (up to 8kWh pre-loaded in the pack, plus whatever the genny made during that whole trip.
Is my math right?
join thE REVolution
+3
Aug 20th, 2010 (10:16 am)I believe they are saying they captured double digits of miles of range. If they recaptured 10 miles of range that would be 2 kWh into the battery.
I calculate that a 3500 lb car with a 7400 ft elevation change represents 10 kWh of energy (rounded from 9.75). Given that a 19 mile dive on level terrain takes roughly half the Volt’s capacity I’ll say that 4 kWh goes into drag over that distance. So It would take about 14 kWh (10 + 4) to get up to the peak, and you would have 6 kWh (10 – 4) to try and recover coming back down. The stated recovery of double digit miles means they recovered 2 kWh or better of that 6 kWh which is a believable recovery rate of 33% (or better).
That 14 kWh climb means a Leaf might well make it to the top if it was fully charged at the bottom. A Volt would need to use it’s generator to supply about 6 kWh to make it to the top, maybe using as much as a gallon of gas.
Aug 20th, 2010 (10:17 am)Not sure I follow the math.
If you have potential energy of 10.78 kWhr, and you recover double-digit miles (lets assume 10 as worst case), then since you need about 250 Whr/mi, this would equate to 2.5 kWhr, or about 25% recovery.
That seems about right. Or, did I miss something here?
+2
Aug 20th, 2010 (10:18 am)Easily. Forgetting about other losses, the potential energy from the bottom to the top is just given by U=MGH. Assuming a loaded Leaf with driver was 4000 pounds and the height is 2100 meters, you’re looking at 10.86 kWh of energy. The Leaf battery pack is only 24 kWh and it can probably only use 80% or at most 90% of that. So yes.
As for recovery, double digit miles would be as few as 2 kWh. So yeah, it could do this.
Aug 20th, 2010 (10:19 am)I known that and agree with your comment, this #42 post was a wink related to the climbing speed & speed detector use, not related to the Volt EREV itself. Have a nice day.
+1
Aug 20th, 2010 (10:21 am)[i]Quote: Yeah. I don’t know the height to the top from where you start, but assuming it’s at sea level, 1600Kg X 4000M X 9.8m/s2 = 62.72M Joules. In which case you’re looking at recapturing 17.84 kWh.
Double digits would be more than half. That would be better than I expected, but that estimate is probably too low since the drop has to be considerably less than I’m assuming. (Or my math is off since I haven’t had my coffee yet).
EDIT: Han has given the height from the base in #60 and it’s half what I used. So I’m not sure I can get double digit kWh from the descent. Have to go back and look at the math. [/i]
I Believe they mean double digit miles, not double digit kwh. using 350wh per mile as a rough average, you’d need only recover 3.5kwh of power. if there’s ~8.5kwh of potential energy then capturing 3.5kwh seems both plausible and impressive.
Aug 20th, 2010 (10:23 am)This isn’t the first go round for regen braking for GM. At Pikes Peak I can’t think of a better way to get quick results. 2kwh in 38 miles back into the T sounds pretty good to me. Just what is the highest rate of deceleration that regen can handle? How efficient is regen when we drive above that 50 mph efficiency red line? Will we actually use the brake pads at all? Perhaps some weight savings are there in reducing wheel braking hardware.
This might be a little off track but maybe the engineers are figuring out a way to bump up the amount of the reserve the car dips into to keep ICE economy high by tweeking regen.
The software must be driving them nuts, but in a good way!
+1
Aug 20th, 2010 (10:25 am)Good point. Along the same lines, seeing what variations result from mass production of what are supposed to be identical cars.
Aug 20th, 2010 (10:26 am)Ooops. This is one of those examples of how you never get the answer right if you don’t get the question right. I thought they were saying they got double digit kWh back. But they’re talking double digit miles. So yes, this could mean a couple of kWh since the EV range of “up to 40 miles” is predicated on using only 200 wh/mile. So two kWh could be 10 miles.
So I guess we also know that under somewhat extreme conditions, meaning a lot of energy in a short time, the Volt’s regen could be roughly 20% efficient.
I wonder how long it takes to descend? I’d assume a slower descent would lead to a higher regen efficiency.
+1
Aug 20th, 2010 (10:32 am)Yes you’re right. Double digit miles. I read it wrongly. No doubt about that. But I think they use a standard of 200 wh/mile since that’s how they get to “up to 40 miles” using 8 kWh.
You’ve got more than 8.5 kWh for sure. The height is 2100 meters and a loaded Volt with driver has to be 4000 pounds. So you’re looking at 9.8 m/s2 X 1800kg X 2100m = 37,044,000 Joules or 10.29 kWh.
Aug 20th, 2010 (10:42 am)I’m thinking along those lines but is regen efficiency comparable to output efficiency? A loss of 80% seems kind of high. 20% loss in battery retention should be about right. Vehicle operations shouldn’t be drawing the remaing 55%. I would also assume that the ICE shuts down during the entire descent even in mountain mode.
Aug 20th, 2010 (10:49 am)And now for something completely different…
http://content.usatoday.com/communities/driveon/post/2010/08/meet-the-top-women-making-the-electric-chevrolet-volt/1
+1
Aug 20th, 2010 (10:55 am)Glad to see more Volt testing… this car should easily be a technological success.
Whether or not a business case can be made for EREVs and the Volt in particular we have to wait and see.
Aug 20th, 2010 (11:02 am)Yes DonC I agree with those numbers. If 11 miles is around 2kwh so that puts the floor at around 20% regen eta. (or higher obviously).
Aug 20th, 2010 (11:05 am)I liked your wink and reference, so was just trying to add frosting. I happen to think that racing improves the breed, especially for EVs. There’s real innovation going on right this second in EV racing, while ICE racing appears, well, pretty stagnant over the past several decades other than (bio)diesel (Lemans and Dakar Rally technical endurance racing comes to mind) and the occasional hybrid system stomping butt. Year over year improvements in EV racing are absolutely staggering to date.
I’d love to see GM run a Volt Cup on technical sprint courses. Race proven gives you massive street cred on reliability, even if end users are all garden variety commuters and errand runners.
Aug 20th, 2010 (11:22 am)hi-ya, superb post.
Aug 20th, 2010 (11:22 am)To quote Rashiid: “Good luck, early adopters…”
I hope those of us who can buy a Volt, whether gen II or III or ? -Whether it be 2012,’13 or ’14….will not get a hybrid Cruze with or without a plug.
It would be nice if we all could be “adopters” of this tested, tested, and re-tested Volt product. There’s a big part of me that believes GM would not do such rigorous, and expensive research just to water it down later for the masses.
RECHARGE!
James
+1
Aug 20th, 2010 (11:26 am)Has anyone heard of 24-32 kwh battery production development at GM anywhere in the world?
I would love for these Volts to be BEV test mules to offer a true 100 mile range!
Aug 20th, 2010 (11:34 am)Available literature indicates regenerative braking adds about 7% to 10% of the mileage you would otherwise get. On a 38 mile trip in charge sustaining more, then one would expect to “recapture” up to about 4 miles, rather than double digit miles (meaning at least 10).
If we assume the Volt gets 5 miles per kwh, then it would need to “recapture” 2 kwh to make it to double digit.
So how do we make sense out of this claim? How much power (kwh) was needed to go down the mountain. Very little. So if the Volt recaptured say .7 kwh of energy, that could provide double digit downhill miles.
+2
Aug 20th, 2010 (11:40 am)They certainly have mountains in Japan as well. Pretty sure there are fine engineers at Nissan as well. They did their homework, there is too much at stake for Nissan here.
+3
Aug 20th, 2010 (11:42 am)More data that helps eliminate a single cars quirks. With 8 cars, you’d see the “culprit”.
Be well,
Tagamet
Aug 20th, 2010 (11:45 am)Hats off to the Edmunds reporter with the adroitness to snap the videos we see here while apparently conducting a test drive of their own.
RECHARGE!
James
Aug 20th, 2010 (11:46 am)Yes Kurt. Thanks for pointing out my mistake. I’m with you on all the numbers. Nice and succinct summary.
Yes. My mistake. Thanks for pointing this out.
+1
Aug 20th, 2010 (11:48 am)True, but stating the obvious – “double digits” spans 10 to 99. I guess we could rule out 41 and up though (g).
Be well,
Tagamet
+1
Aug 20th, 2010 (11:48 am)In theory, a regen braking system can capture almost as many kWs as the motor can put out (i.e. 15 KW motor, should be able to produce about 15 kW during regen). However there are several bottle necks. The output voltage of the motor during regen, cannot exceed the upper input voltage of the motor/charge controller, and the motor/charge controller output cannot exceed the overvoltage rating of the battery pack. The battery can accept a much higher rate charge when it is depleted. So, you’ll capture much more regen at the top of the hill than you can at the bottom.
This is an area when an EV really wins out over a hybrid like the Prius. The small-capacity batteries on the Prius quickly reach their max state of charge…and no further regen energy can be accepted, whereas the Volt should have enough charge capacity to accept A LOT of regen braking before having to to rely on the actual brake pads for deceleration.
haha…I see someone gave me a -1 on one of my prior comments. If I’m wrong on something, or have misunderstood something…PLEASE correct me. I don’t like to spew mis-information, but I DO make assumptions sometimes.
+2
Aug 20th, 2010 (11:49 am)Whatever it is, it will get better in the years to come. So why focus on that thing so much ? The Volt is an electric car with a plan B on board so you never have a problem with the range of the car. For most, I believe we will stick to plan A (pure electric) almost all the time. I know it’s my case. And as public charging stations are more and more implemented, the CS mileage will become totally irrelevant.
So I don’t care that much about CS MPG unless it is truly awful. And even then, I wouldn’t mind that much. Being able to very seldom go to a gas station and fill up is what I care about.
The Volt is the best technological compromise so far, no matter what the CS MPG is.
Aug 20th, 2010 (11:55 am)I don’t think they have room in the housing for more than 16 kWh so they’d have to repackage everything.
+2
Aug 20th, 2010 (11:56 am)Sounds like a BEV would be a better fit then.
I think a lot of people care about CS mileage. I for one care, from the view of knowing how efficiently you can run a generator to power the vehicle. If it comes in any where near 40mpg, then I have other ideas for my future car.
My best engineering estimate is 37mpg combined hwy/cty, but I really think that is still a stretch. Maybe low 30′s, based on a lot of other efficiency losses that I did not put in my original calculations.
+1
Aug 20th, 2010 (11:58 am)If you pulled out the ICE and all its supporting cast members, you could easily add another 16 kWhr of battery.
+2
Aug 20th, 2010 (11:58 am)I am so fervent (and have been for a long time) about avoiding jackrabbit starts and delayed braking that my wife used to call me a ‘freak of nature’. Our ’93 Olds Roadmaster did not need a brake job until 110,000 miles (and that was, of course, without regen braking). Now that I have multiple hybrids (with regen braking), the cars might be gone before the brakes are. The nice thing about these regen cars is that they give you a visual indication about engine performance during braking. I believe they make your wife, my wife and a lot of other drivers into people who no longer wait to slam on the brakes until the last second. Brake jobs may become so infrequent that they might end up being considered a system failure instead of the routine maintenance that they are now. Just one more benefit of an EV
Aug 20th, 2010 (11:59 am)Well to get double digit miles, you would need to get 2kwh back, since the Volt goes 40miles on 8kwh. I assume they are saying you get double digit miles of net energy at the bottom. This means w/the wipers running, radio on, etc., if you started at the top of the mountain with 4kwh in the battery, at the bottom it would register 6kwh min. That’s the way I interpreted it. This is amazing to me because picking up 2kwh in just 19 miles seems like a lot.
Aug 20th, 2010 (12:00 pm)Long time reader of GM-Volt, first time poster…
Does anyone have any information on how bad the insurance companies are gonna stick it to us to insure this car. I curious what they will base the cost on, cost of replacement parts? Availability of repair centers? etc..
Aug 20th, 2010 (12:04 pm)Nice comment. +1. Now ignore the voting. Most of the time they’re noise. Plus being right doesn’t necessarily make you popular.
Well at least 10-40, but I think those rose tinted glasses are now just plain Volt red! These guys are in marketing mode, so if they had anything close to 40 miles we’d be hearing something other than “double digit miles”. Probably “mid double digit miles”. FWIW 10 miles is good. If you think about it, imagine being at the top of Pike’s peak without any gas. You now go twenty miles down the hill and you can go another ten more miles.
I’d still like a freehweeling option. There are no conversion losses or other limitations with freewheeling.
Aug 20th, 2010 (12:06 pm)Range anxiety is real. Until there are enough public charging stations available, the Volt is a better vehicule than a BEV. Especially for car #1 of the family. For car #2, it’s an open debate.
P.S. High 30′s MPG would be absolutely acceptable. The gas generator will be useful for only a couple of years so…
Aug 20th, 2010 (12:08 pm)I also have a Prius and the regeneration feature is one of the coolest things about hybrids. On a trip through the Rockies last year it was a real blast watching the battery state go from low to high in a very short time downhill. ( hi to low likewise when climbing… but as fast as any regular car…:+])
It would be even more fun in a VOLT because of the battery size.
BTW the “b” feature on the Prius does not increase the regeneration feature. Light foot pressure on the Prius brakes does that.
Like you, we have 60% brake capability at 97K miles on the Prius.
Aug 20th, 2010 (12:10 pm)Since most Volt drivers will be mature and responsible persons, wealthy enough to afford the car, I don’t expect that much of a surcharge insurance wise.
+1
Aug 20th, 2010 (12:10 pm)Check out LandKurt’s post at #69. I think that’s a great summary.
I don’t think it’s realistic to think of it as being 19 miles because the critical thing is that you’re recapturing all the kinetic energy as you move from (literally) a higher state to a lower state. So it’s more that it’s recapturing 2 kWh of the 6 kWh or so (maybe less given the other electrical loads maybe more given the speed) that are available for recapture. The miles per se aren’t so important. If the drop were the same over half the distance you could recover the same number of kWh.
+2
Aug 20th, 2010 (12:12 pm)I like free wheeling too ….. but your brakes would MELT going down grades not even 1/2 as bad as Pikes Peak.
+2
Aug 20th, 2010 (12:13 pm)It could be that they have different software algorithms running in each car, or the same algorithm with some settingns tweaked slightly differently in each one. That way they could compare the performance of the different software for essentially identical runs. The first run up the hill could be with the exact same software to prove the cars are otherwise identical or very close. Then they could do another run with various parameters changed in each car to find the best setup for mountain mode. Of course I am just guessing, but it seems like a good possibility.
Aug 20th, 2010 (12:23 pm)I can’t wait. I brake pretty hard and go thru a lot of pads/rotors/calipers. I’m looking forward to regen, however little or great it will help. (yes i know even with regen slamming the brakes will still use the pads/friction)
Aug 20th, 2010 (12:23 pm)=============================
Just one small quibble:
I don’t want some Volt that has had the crap beat out of it going up and down Pike’s Peak!!!
I want a new one………………
Aug 20th, 2010 (12:24 pm)Many here have suggested that the engine/generator could be removed to make space for extra batteries in a Volt-derived BEV. I don’t think this would be a marketable solution for a number of reasons (mainly because the Volt was specifically designed to carry an engine, and too much on the car reflects this to make a reasonable BEV).
However, I think it is a very plausible scenario for a BEV test mule. It would be a much easier proposition than was converting Malibus to be the first Volt mules. Who knows? This BEV mule might work out so well that I’d be proven wrong, and a Volt-derived BEV might be offered for sale; but I still think that if GM fields a BEV in America, it should be capable of reasonable, Volt-like performance over a real world range of at least 100 miles. Remember, the Volt is heavier; and it can use more energy if the driver really “puts his foot in it.” We’re talking much more overall capacity than is used in the LEAF.
Frankly, I still think that the ideal EV for this country would be an advanced-battery EREV which can go 80 – 100 miles on electricity, with a much smaller engine/generator as a backup. I hope GM builds on it’s current lead in this area to produce such a vehicle within 6 – 8 years.
Aug 20th, 2010 (12:29 pm)It could be that they have different software algorithms running in each car, or the same algorithm with some settingns tweaked slightly differently in each one.That way they could compare the performance of the different software for essentially identical runs.The first run up the hill could be with the exact same software to prove the cars are otherwise identical or very close.Then they could do another run with various parameters changed in each car to find the best setup for mountain mode.Of course I am just guessing, but it seems like a good possibility.
Yep, that too! +1.
Be well,
Tagamet
+1
Aug 20th, 2010 (12:39 pm)I suspect that this could be a one of the most influential issues for BEV’s and EREV’s.
http://news.yahoo.com/s/ap/20100820/ap_on_bi_ge/us_oil_prices
So, if gas drops down to near $2/gal. will people clammer for more BEV’s, EREV’s, and hybrids?
The gas tax is really the only way to ensure that oil companies cannot destroy the EREVolution and other similar battles on the efficiency front line.
Aug 20th, 2010 (12:44 pm)I tend to resist any new tax (or tax increase), but if I could be assured of such a gas tax’s proper use (for roads, battery research and related concerns), I might be persuaded. IMO, this assurance isn’t very likely. More money coming in usually gets spent in the manner which gets the most votes for one party or the other.
Aug 20th, 2010 (12:46 pm)Not really. With the freewheeling option regen is engaged as soon as you hit the brake. I’m assuming a minimal level of driving competence where you ride the pedal softly so the car doesn’t go careening out of control.
Coming down from Pike’s Peak would not be that different, but going down the smaller inclines that you’re likely to find would be more efficient.
+1
Aug 20th, 2010 (12:46 pm)Freewheeling down Pike’s Peak would be a problem. Better to control the speed with regen.
Aug 20th, 2010 (12:50 pm)I am in total agreement. The tax should just shift burden to gasoline and be proportionately reduced in other areas. The idea is not for the govt to collect more money, but to make the cost of fuel more proportional to its real cost. The tax should basically be used to pay for the cost of our military (not increasing but maintaining), since this has a direct cost for our fuel dependency.
At the end of day, your average tax remains the same.
Aug 20th, 2010 (12:54 pm)I’m guessing it would be similar to any other $40k Chevrolet sedan. Being a Chevy, replacement parts would be a little cheaper than say a $40k BMW.
Higher insurance rates are more dependent on high-performance cars or small pickups in children’s hands. It’s all based on the insurance company’s tables based on past experience. Us old fogeys with a couple cars and home insurance probably won’t see a huge increase.
I have been reaching out to Allstate. No answer about Volt or LEAF insurance yet.
Aug 20th, 2010 (12:55 pm)You could put the batteries where the engine is but you wouldn’t have the protection you’d need and at the very least you’d need another liquid heated and cooled housing. Doesn’t seem practical.
The range business is interesting. 75% of daily driving is 40 miles or less. 90% of daily driving is 100 miles or less. To pick up that extra 15% you’d need to increase the cell cost by at least 25% — just doesn’t seem a very good idea based on a cost benefit analysis. Plus once you start recognizing the possibility of opportunity charging, there are 120V outlets everywhere, even going 100 miles a day in a Volt doesn’t mean you’ll be using CS Mode at all.
I think the Volt’s big issue is cost. Range is secondary. GM needs to get the cost down and adding battery capacity is not a way to do this.
+2
Aug 20th, 2010 (12:56 pm)Free wheeling would be the most efficient way to get the most out of your driving. This allows you to “glide” with zero energy usage.
Regen should still be available, but when you when your driving on more moderate terrain, you would not use regen that often. Regen would be effective for large hills/mountains and for stop/go city traffic, where you need to slow down more aggressively.
Recovering 25-30% of energy in regen is nothing to sneeze at, but allowing the driver to free-wheel for specific conditions would easily payback much more in your total energy budget.
+2
Aug 20th, 2010 (1:01 pm)The US uses 138B gallons of gas a year and the DOD budget is $664B. So a tax of $4.81 would be about right.
With gas near $8/gallon no doubt GM could easily sell 250,000 Volts a year.
+4
Aug 20th, 2010 (1:02 pm)Just some advice for folks out there with the delayed braking habits:
-Always look for the next stop light- no matter if it is over a mile away, or even more
-Factor in that any drivers in front of you will have to stop before you do and those sitting at a red light will take awhile to get up to speed
-At the very least, take your foot off the accelerator and coast if it appears you may have to slow down
-And brake lightly, long before you really need to, because NOW you know that any (most) of your braking energy done at this level of brake pedal movement will be returned to you once you can pick up speed again.
-oh yeah, and get used to laughing at people who have to fly by you because you are not going fast enough- even though all they are accomplishing is to race you to the stop light.
Common sense, but something I witness every day that few seem to embrace.
There is one more thing to add. If you are driving the same routes repeatedly, you will become familiar with traffic light cyclling and adjust habits accordingly. For instance, with short cycling lights that turn green while you are way off- just forget it. By the time you get there, it will be red again anyway. Our tendency is to pick up speed when we see a light turn green so you make it through before it changes again. However, you often realize that all you did was to waste gas (now electricity) just to come to a dead stop anyway. Likewise, if you are way off from a light that just turned red (because you saw another car trip the sensor at the cross street), you may just want to coast a bit if it is a short cycling light and turn back to green for you within 15 seconds.
Adoption of these habits will be even more rewarding once you get regenerative braking because you know that light braking gives you something and heavy braking gives you nothing.
Aug 20th, 2010 (1:04 pm)Of course at some point you’re going to exceed the capabilities of regenerative braking and start losing energy to the brake rotors. According to post #42 the average grade of the top 12.4 miles is 7% with a maximum grade of 10.5%. I doubt the Volt regenerative braking system can handle twice that grade without resorting to friction braking.
What I want to know is how fast you generally drive down Pike Peak. Does it take half an hour to go that 19 miles? Recharging 25% of the battery in half an hour is not too shabby.
Aug 20th, 2010 (1:06 pm)Gents, consider the Casimir effect and then let’s talk.
Aug 20th, 2010 (1:06 pm)If the GM engineers need a really steep hill they should come to North Bergen NJ.
So steep a car feels like it could flip while climbing the hill.
NPNS!
+2
Aug 20th, 2010 (1:07 pm)Another revealing testing location would be the all-paved road to the top of Haleakala on Maui, with its approx. 10,000 feet of verticle. You’d go from sea level and warm and humid to cold and dry at the top, with an increasingly steep grade.
Of course, if you wanted even more verticle, you could do the road to the top of Mauna Kea–almost 14k feet. I can’t think of any other bigger verticle gain road in the US.
For you ‘now you’ve gone too far’ dreamers like me, when they build a road to the top of Olympus Mons on Mars, you get 88k vert one-way. The regen on the way down could power a small city.
+2
Aug 20th, 2010 (1:08 pm)I’ve never done Pikes Peak, though I spent (c. Stone Age) over a half year at Lowry AFB. (Denver) I did made Lookout Mountain (Buffalo Bill’s grave) on weekends. However, even though the two mountains (7300 ft.) are comparable in elevation, Pikes Peak is 7600 ft.-the latter drive being zuper duper tough.
Pikes Peak Highway is quite steep. Here’s the highway stats I copied from a Pikes Peak Highway brochure:
Length – 19 Miles
Surface – Pavement & Gravel
Elevation at Tollgate – 7,750 ft.
Elevation at Summit – 14,110 ft.
Maximum Grade – 10.5%
Average Grade – 6.7%
Now there’s a diff between % grade and degrees grade. However, its fair enough to assume under 6%–the diff between degrees and % grade being minimal. Consulting my handy
Larminie and Dicks EV’s Explained (I cited these guys yesterday for fuel cells – they’re very good.) … at 10 degrees the load equates to better than 10 times zero incline.
Also…on interstate highways… its 6% max grade. Here in Cal. typical mountain driving 5% grades. The reason for these closely controlled grades relates to truck braking. On inclines of 3%-5% over a few miles, truck brakes can smoke. Standard practice is a truck runaway outlet road to reign-in the big guys in deep yogurt.
Therein lies the issue VOLT engineers cheered – regen braking. Getting there is one thing – getting back could be another. How bout a contest between LEAF and VOLT starting in San Francisco to Reno and back. Winter’s coming.
Aug 20th, 2010 (1:09 pm)Voltville.
Aug 20th, 2010 (1:11 pm)Hey guy, what part of OPTION don’t we get here! LOL (only kidding). Realistically going to a stronger regen isn’t any different that what they have now with the two modes. Freewheel would just be a third regen mode. As to whether this is workable, they have two regen modes now so obviously they think people can handle switching modes, and really moving out of freewheeling on steep grades is no different than moving to a lower gear on a conventional car.
Not seeing the problem of having the option, though you’re right it wouldn’t be the best choice all the time. But I think I’ve been down Pike’s Peak once in my life so far whereas I drive most times on highways where the freewheeling option would be more efficient.
What you said. I actually don’t understand why this was ruled out other than a misplaced notion that it wouldn’t be “like” an ICE vehicle. Would be an interesting Q to ask.
Aug 20th, 2010 (1:13 pm)What about a Federal gasoline tax that equated to a 1% income tax decrease? Use the numbers for the average person in the USA.
Aug 20th, 2010 (1:15 pm)Zero energy use? You’re still using energy for your accessories and still losing energy to drag. In an ICE car you’re still using gas to keep the engine idling while free wheeling, aren’t you? So what you mean is that free wheeling minimizes the engine drag energy loss. I’m under the impression that electric motors won’t have nearly as much drag loss as an ICE engine with its pistons. Free wheeling probably won’t gain you as much in an electric car.
-1
Aug 20th, 2010 (1:16 pm)GM agrees, which is why their stated focus for > Gen I is cost reduction.
Aug 20th, 2010 (1:23 pm)Looked like 30-40 MPH on the video and that seemed a flatter part. You’d have to think a safe speed at the top sections would be slower. So your guess of half an hour seems pretty good.
If regen car recover 30% that’s very good. I suspect they used the “L” mode for the descent since I doubt that they were maxed out on regen capability for most of the descent.
+1
Aug 20th, 2010 (1:29 pm)Nice Nelson, so true. I live and work in Bergen County. I’m hoping in the future to bring my Volt to a few of the local car shows next summer and see the reactions I get.
-1
Aug 20th, 2010 (1:29 pm)When you freewheel in an ICE you could turn the engine off and put the car in neutral. That’s a hypermiler technique.
But here’s the deal. When you use regen you have all the conversion losses going from mechanical energy to chemical energy and then back again. Just going one way those losses are 70%.
You avoid all these losses using freewheeling. JEC’s point was that freewheeling just converts mechanical energy to mechanical energy. As you note, you’ll still have all the losses you normally do, like drag or rolling resistance, but you’ll have all the energy to overcome these losses without incurring any conversion losses which are substantial.
Aug 20th, 2010 (1:33 pm)Yes, any accessories you have will consume power. So, having that 5000 watt amplifier for your stereo booming is going to cost you range/power.
What I meant was that when you free-wheel, you are putting ZERO power to the motors and by opening the stator winding you would have very little reluctance for free-wheeling.
Since you always lose energy from drag, and this is basically a zero net between free-wheeling and normal propulsion.
It seems like a simple and common sense way to operate an EV, I just do not understand why GM and others do not make it readily available.
+1
Aug 20th, 2010 (1:34 pm)But since Mars has weaker gravity than Earth Olympus Mons’ 88,583 ft is equivalent to a height of 33300 ft on Earth. Measured from it’s oceanic base Mauna Kea is about that same height. So all you need is a subsea tunnel going all the way down to the base and you can achieve about the same thing without ever leaving Earth.
Aug 20th, 2010 (1:34 pm)EDIT: I see DonC beat me to the punch. His description hits the nail on the head.
+1
Aug 20th, 2010 (1:36 pm)Thanks for the useful tidbit of knowledge…I will add it to the library of useless facts that I keep in the basement.
Aug 20th, 2010 (1:38 pm)+1 to you Timaaayyy, you have won my “best expression of the day” award for today.
+1
Aug 20th, 2010 (1:44 pm)And then some jackass passes you, changes lanes and slams on the brakes. Ya can’t win with commuters as there is no way to maintain following distance much less anticipate lights.
What we need is a low-speed cruise control that always maintains 10 feet of following distance. That way, only a Mini or Smart can jump in front of you.
-1
Aug 20th, 2010 (1:45 pm)Free-wheeling does make sense in low-deceleration conditions…like slowing slightly to time stop lights or something.
Going down a long, downhill stretch is a completely different animal. Once the drag losses are overcome, the gravity will continue to accelerate the car at which point you’re going to have to use brakes (or regen) to maintain control. My guess is that it would just feel “too weird” for most people if the car was in a full-coast mode. It the wrong hands it could even be dangerous.
Ask anyone who’s accidentally put their motorcycle into neutral coming into a hair pin turn. It’s a butt-puckering experience to lose engine braking.
+1
Aug 20th, 2010 (1:49 pm)I’m equally fervent about using the brakes as little as possible. As a result, I have traded in cars with 100,000 miles on the odo and the original brakes still good. So I’m really looking forward to regen braking, and the “Low” mode.
Now, if only I could get religion on the jackrabbit starts as well, ….
-5
Aug 20th, 2010 (1:59 pm)Yep.
Car weighs ~ 1750 kg
Elevation change 4300 meters
So potential energy is 73745000 joules, or 20.5 kwh.
If the distance traveled is 38 miles down and 200 wh/mile is used, the road distance consumed 7.6 kwh. All in all, having 2 kwh left at the bottom suggests a regen efficiency of 2/(20.5-7.6), or 15.5%.
If correct, this is lackluster regen performance. Perhaps the battery SOC was at a deficit below normal CS mode at the top the mountain I am not accounting for.
-2
Aug 20th, 2010 (2:13 pm)Mountain climbing in a 1750 kg car with a 50 kw motor is a bit of a joke. Sure you can do it, but I bet a looong trail of cars are behind you by the time you get to the top.
I can see the headline now: “Road rage on Pike’s peak.”
Aug 20th, 2010 (2:16 pm)#102 Nutron BTW the “b” feature on the Prius does not increase the regeneration feature. Light foot pressure on the Prius brakes does that.
Thanks for the heads-up, my wife hates to read any manual and I couldn’t find it on line, so I just assumed that B mode increased regen.. After searching, I discovered out that B mode is = engine braking plus normal regen. if soc in battery permits. So now, does the L mode in the Volt increase regen?
#99 smity x Says
Aug 20th, 2010 (12:00 pm)
Long time reader of GM-Volt, first time poster…
Does anyone have any information on how bad the insurance companies are gonna stick it to us to insure this car.
I heard a commercial by Farmers insurance that said they were lowering cost for hybrids. However when I enquired about coverage for a Leaf they could not give me any info without a VIN. So your Q is a good one and who knows how they might rate these vehicles.
Aug 20th, 2010 (2:18 pm)Thanks, MOM–aren’t Friday’s fun?
Aug 20th, 2010 (2:19 pm)I keep mine in my head.
Aug 20th, 2010 (2:22 pm)Your EV will help you with the starts, too. Before we got a Prius, our son would always take off with way too much acceleration down our small street. It wasn’t like he was squealing the tires or anything; I just heard the engine noise. Most cars, until now, had little other than engine noise to tell you if you were accelerating too fast. In fact, the more powerful the car, the easier it was to depress the pedal too far. I am assuming your Volt will be like the other sortaEVs we have had and visually show you what acceleration is doing to your energy usage. After we got the Prius, our son ‘got religion’ on the acceleration issue. He took it as a personal passion to compete with us (his parents) on mpg ratings for his various trips. So, if you are indeed obsessed with brake wear, I am pretty sure you will conquer this acceleration issue after the EV shows up.
Aug 20th, 2010 (2:24 pm)Volt V1.0s or V2.0s ?
I thought V1.0s already gone through all cycles and now V2.0 are in testing.
BTW : was there a 100% or 99% calibration ride ?
-5
Aug 20th, 2010 (2:28 pm)Ahh, more fun with numbers.
I’ll take 10% grade to mean 1 meter up for every 10 meters advanced.
2.2 mph is about 1 meters/second, which takes 0.00476388889 kwh;
So, this is 17 kwh/hour.
If the Volt ICE is screaming to put out its absolute last rpm, it can climb 3 meters a second, or travel 66 mph on a 10% grade. Just don’t expect to accelerate, and remember: no people in the car
+6
Aug 20th, 2010 (2:31 pm)I get twice the regen performance using 7400 ft elevation change over 19 miles. They didn’t drive from sea level and the 38 miles was round trip. So I get 6 kWh as the amount needed to be bled off by brakes/regen.
The Volt has a 111 kW electric motor, which car are you talking about. Sure it only has a 55 kW generator, but mountain mode reserves some extra energy in the battery and even the Pikes Peak road isn’t a continuous uphill grade, there is some chance to recharge the battery at points.
By my figuring you need about 14 kWh to climb the 19 mile 7400 ft elevation. A 55 kW generator can produce that in 16.3 minutes. That would give an average speed of 74 MPH. Is that your idea of a bit of a joke?
Aug 20th, 2010 (2:32 pm)As I see people fly by me often (due to my pokey acceleration and early/mild braking and coasting), I know what you are talking about. However, I see very few get back in my lane with no stopping room. Yeah, there are a few who are vindictive and endanger you and themselves. However, most who get irritated with you do not analyze the distance and time of their irritation with you. After they pop into the passing lane and floor the accelerator, they end up having no time except to slam on the brakes, nearly rear ending of the car already stopped in the adjacent lane. It is as predictable as the sunrise.
Aug 20th, 2010 (2:33 pm)But could it climb Mt. Tampa?
ah, no roads on it so we’ll never know.
It’s what my friend and I named the big phosphate hill that we can see while we’re fishing in parts of the bay.
+1
Aug 20th, 2010 (2:37 pm)How about using it to fund the $7500 rebate?
Aug 20th, 2010 (2:47 pm)LankKurt, if the descent is 19 miles and not 38, and the elevation change is as you write, then the arithmetic works out to
2/(10.75-3.8) = 28% regen efficiency.
This is the problem with trying to work off marketing speak — details are missing. We have probably defined the upper and lower limits of what the regen will actually turn out to be.
I know the motor is 111 kw, but the ICE is ~ 50 kw. Unless you have a way to keep the ICE screaming all the way up the mountain so that battery regen happens on the “low” grade portions, this is a pretty pure CS (ICE only) test.
+4
Aug 20th, 2010 (2:52 pm)Your certainly right, I think the easiest way to pi$$ off most driver is to simply drive the speed limit. Obey they laws and you will get raged on all day and night. And I love when people speed past me all angrily then I time the stop light correctly and end up ahead of them as they have to accelerate, then they floor it and brake again, i keep coasting along rarely stopping, its great!
-8
Aug 20th, 2010 (3:13 pm)I have never driven Pike’s Peak, but I live on a slope of a 5000 feet (~ 1600 meter) mountain, and have driven to the top a couple of times in our Prius. From my experience mountains are a challenge to low max power cars because you have tight turns that force you to slow down to ~ 10 mph, and then you want to accelerate on a steep incline.
I know my Prius can accelerate, or keep a nice speed on a high grade, but I do not try to do both at the same time. If I remember correctly, the Volt ICE is 70% max of the Prius ICE, and the Volt is ~ 30% heavier. That is the same as cutting my Prius ICE in half. Ouch
I don’t have a handy number for what usual drivers expect in the way of acceleration in this kind of mountain driving, but the Volt is going to perform way below.
+1
Aug 20th, 2010 (3:14 pm)Yeah man +20.
And it works out great with closely spaced lights. Because of my pokey acceleration, I end up often with lots of space in front of me. All the impatient drivers get in the left lane and stack up. Then, as you say, you time the light right, never had to put your foot on the brake once and fly by them as they are at a dead stop. As I KNOW they are perturbed with me flying by and their impatience backfired, I have often wondered if ANY of them ever reconsidered their fuelish ways and learned from the experience. Probably not.
Aug 20th, 2010 (3:17 pm)But the Volt engine is not powering the wheels, the tourque will come from the electric motor which will have a battery reserve of 30 – 40% depending on whether or not you put the vehicle in mountain mode. I think this is not going to be an issue with the volt. That being said I have yet to have any sluggish acceleration moments in my 2010 prius – its not a sports car, and that is not what should be expected out of these vehicles. But if i want to I can squeel the prius tires, it has plenty of go when needed.
+1
Aug 20th, 2010 (3:18 pm)According to the road stats in post #42 there is 0.8 miles of downgrade on the way up with a maximum negative grade of 10%. So there is a chance to recharge the battery a bit on the way up.
By your own figuring you’ve got the Volt able to maintain 66 mph on the worst part of the road without any battery use. Now have a look at the video accompanying the article. Notice the tight corner at the beginning and the speed of the oncoming cars. Do you really think there is much chance to get up close to 66 mph on this road in any car?
Do you stand by your “bit of a joke” comment after working the numbers? The numbers indicate a great hill climbing car to me and we have the Volt testing team expressing their satisfaction. I suppose we won’t know for sure until some third party actually tests it under mountainous conditions.
Aug 20th, 2010 (3:23 pm)..and your local long-suffering Chevrolet dealership sales staff, which gets yet another great product after years of blandness and quality stumbles. Must be fun to go to work again. Good on ya.
-2
Aug 20th, 2010 (3:34 pm)LandKurt, the 66 mph is steady state, with the car screaming at the top of its lungs, with no luggage or people weight. And as I posted later, the performance deficit likely happens when the driver wants to accelerate out of a hairpin turn.
Just ballpark, half the ICE is spent on elevation climbing, leaving 25 kw to accelerate 2000 kg. That is coming close to 1/10th of what many people are used to.
+3
Aug 20th, 2010 (3:46 pm)Again your basing your information on the power output of the generator which IS NOT tied to the wheels. The motor has higher output, and a battery buffer of 30-40% to get you in and out of these situations comfortably.. You are failing to grasp the concept of the volt here.
+3
Aug 20th, 2010 (3:52 pm)I dunno about that. Let’s say you’e going 40 MPH, which seems like a reasonable or even fast speed for a twisting climb up Pike’s Peak. That’s 18.33 meters/sec. On a 10% grade you’re climbing at 1.83 meters/sec. Assuming a loaded Volt is 1800 kg, you’d need 32 kW. Just from the genset you have another 20 kW. Plus you also have the power from the battery.
And that’s on a 10% grade. On the average 6% grade you’d only need a little more than 19 kW for the climb, leaving 34 kW from the genset.
Granted this is not V12 performance but the Volt isn’t supposed to be a race car.
-5
Aug 20th, 2010 (3:53 pm)Battery buffer of 30% of *what* ? The total battery capacity ?
First off, if you think the engineering is going to let the driver take the SOC down to zero, you are clueless. Second, when the battery dips down below the usual CS SOC level, how is it going to regen back up ? While going uphill on an average 6% grade ?
Aug 20th, 2010 (3:57 pm)OK Eric. The Volt won’t do well racing up Pike’s Peak while taking the family on a camping trip.
-1
Aug 20th, 2010 (4:00 pm)DonC, by ‘loaded’ do you mean the car has a backup camera, too ?
Just the car is 3800 pounds I believe. Add four people at 200 lbs a piece, and my arithmetic says 4600/2.2 = ~ 2100 kg. I’ll assume there is no room for luggage
But yeah, we come up with similar numbers, that the Volt will have about 25 kw to accelerate its hefty behind. Assuming max rpm.
+1
Aug 20th, 2010 (4:01 pm)Driving the speed limit in the fast/passing lane will get you shot at in Texas and California.
It is unlawful in most states to hang out in the passing lane and not pass anything.
+1
Aug 20th, 2010 (4:03 pm)Er, the Volt uses 30 kW going 65 MPH on a slight uphill. The genset produces 55 kW. I don’t believe that it’s accurate to describe a genset producing slightly more than 50% of its capability as “screaming at the top of its lungs”.
+1
Aug 20th, 2010 (4:03 pm)Any time the driver is demanding less than 55 kW from the car is a chance to recharge the buffer zone of the battery from the generator. As DonC has pointed out, if you’re only going up that mountainous road at 40MPH there could be 20 – 30 kW left from the generator to recharge the battery with. If you think the engineers haven’t programmed the controller to take advantage of that, you’re clueless.
-5
Aug 20th, 2010 (4:04 pm)I think I would rephrase that to: rent a car for the trip.
+1
Aug 20th, 2010 (4:08 pm)Most estimates have it more at 3500 pounds. Since we were on a camping trip, I had the kids at 50 pounds each, mom at 120 pounds, and dad at 175 pounds. Plus a tent and some stuff — ya gotta bring all that stuff when you’re racing up Pike’s Peak.
So roughly 1800 kg. But yeah, another 100 kg won’t make much of a difference.
+2
Aug 20th, 2010 (4:11 pm)That’s what my friends who own a Prius do. (That’s the truth, not a joke). Makes sense. No reason to have a land yacht for those occasional family races up Pike’s Peak.
Aug 20th, 2010 (5:55 pm)Even these actions will really annoy some people. Imagine what they think of some of the hyper-miler’s techniques.
Aug 20th, 2010 (6:00 pm)This is great that they are testing high end stress …. but I will never need this car to do anything near this stressful.
Great discussion ….. about a great new technology… very good to hear.
What I want to know is the corrosion resistance and long term endurance.. I live in PA … lots of salt and potholes. What will be the condition of the VOLT in 10 years… my Buick with 95K of very hard miles runs and looks like new… I’m wondering how the VOLT will last?
The driveline should be fine… the brakes should be fine… are they putting in the galvanized metal and stainless steel exhaust like my BUICK? How about the all alloy brakes that are so easy to change .. no rusted bolts?
+1
Aug 20th, 2010 (6:01 pm)Does passing gas count? Then I will be just fine, all day in the fast lane, doing 55!
Aug 20th, 2010 (6:02 pm)Hey, I thought you weren’t going to comment? BUSTED
Aug 20th, 2010 (6:11 pm)Late in the thread for me. Someone may have brought this up but…..
““By the time the Volts made it off the hill, they had recaptured double-digit miles of energy,” said Peterson.”
So what is “double digit”? When my son hit 10 he hit “Double digits”
-4
Aug 20th, 2010 (6:20 pm)Yep, that is what I would do too. No car is the best tool for every trip.
-3
Aug 20th, 2010 (6:23 pm)How about a 10% grade, which is what I calculated ?
Aug 20th, 2010 (6:25 pm)You are making the rash assumption that the Volt was not able to take full advantage of re-gen because it couldn’t hold more charge. This is highly unlikely. a more reasonable scenario is max re-gen by Volt or LEAF is about 3 or 4 kwh, well within the battery capability of either car. If the re-gen was sufficient to fully charge the battery I think Peterson would have said 40 miles, instead of “double digit”.
Aug 20th, 2010 (6:31 pm)Why, going that fast on Pikes Peak is likely to get you a speeding ticket, there is no reason you should be doing that fast on a road such as that.
Aug 20th, 2010 (6:35 pm)As my favorite person, Al, would say “Spooky action at a distance”.
-7
Aug 20th, 2010 (6:37 pm)It is far from obvious to me that the “mountain mode” will work as you guess. Not to say the engine control mode could not be that way technically, but rather the trade-offs make me skeptical.
For one, drivers might object to the engine screaming all the way up;
second, the fuel efficiency will be *terrible*;
and third, I don’t know if the engine is built for that kind of abuse.
Somewhere along the line GM must also design the car to prevent driver abuse. In an owner can just leave the car in mountain mode all the time to enjoy “performance,” you can wipe resale value to zilch.
It is (IMO) silly to engineer a car like the Volt, which already is a study in compromise, to handle Pike’s peak when 99.999% of driving will be much less demanding. Good PR maybe for people who think “if it can handle Pike’s, it is good for anything,” when engineering reality is more along the lines of “if we have to handle Pike’s, regular driving and longevity is going to be less optimized.”
-2
Aug 20th, 2010 (6:43 pm)Quite right, and of course not. I was just calculating one aspect of the weight/ICE performance of the Volt. If you read later posts you will see calcs of scenarios that involve acceleration on an incline. Much …. errr … safer, I assure you
-4
Aug 20th, 2010 (6:59 pm)Is GM still tweaking Version 1.0 of the Volt ? If so, they are asking for an awful lot of money to be a beta tester.
+2
Aug 20th, 2010 (7:41 pm)How do you think I’m “guessing” that the mountain mode operates? I think it simply sets a higher level of charge for starting the engine, giving you a larger buffer of power for supplementing the 55 kW from the genset. That’s more time accelerating harder than 74 hp. How much more I don’t know. If you leave your Volt in mountain mode all the time all you’re doing is reducing your all electric range (and effective mileage) in order to have a larger emergency power buffer. I don’t see how it would hurt the car or your resale value.
You’re assuming the Volt’s 1.4 liter engine will be screaming and abused to produce a continuous 74 hp (55 kW). They put in a larger engine than orginaly expected, much larger than many prefer. The 55 kW limit on the engine/generator pair may be a limit on the generator rather than the engine.
But you are right in that we don’t know how aggressive the Volt will be at recharging the battery if it reaches a minimum SOC. I feel safe in assuming the battery will not only be recharged by the regenerative braking but use the genset to get the battery up to an acceptable charge level (a higher level when in mountain mode).
+2
Aug 20th, 2010 (7:52 pm)+1
Aug 20th, 2010 (8:04 pm)So you want to go up a 10% grade at 65 MPH? Interesting. You can always come up with a scenario where a car won’t work. Let’s just say that all gas stations in a two hundred mile radius are shut down. How will you drive to work in your Prius? You won’t. But you’ll say, that’s crazy, this can’t possibly happen. Yet you’re perfectly happy coming up with 10% grades — even though the maximum grade on an interstate is 6% — where you can go 65 MPH AND the Volt won’t have any battery left AND Mountain Mode won’t work like GM says it will.
Let’s be realistic and not go to the unrealistic “no gas stations so how will you drive your Prius” type scenarios.
+1
Aug 20th, 2010 (8:07 pm)“Nothing to see here. Move along…. ”
Be well,
Tagamet
-1
Aug 20th, 2010 (8:09 pm)Check out the stats on the map someone posted @42.
Be well,
Tagamet
-4
Aug 20th, 2010 (8:53 pm)LandKurt,
I said “guess” only to mean that neither of us actually know what the mountain mode entails. I surmised an abusive mode thinking of lower DOD, but you make sense in suggesting a higher CS SOC.
Now that I think about it a bit, 53 kw does sound low for a 1.4 liter engine. But isn’t the m/g that accepts up to 111 kw from the battery the same component that you think is limited to 55 kw from the ICE ?
-3
Aug 20th, 2010 (8:56 pm)No. See post #184
-4
Aug 20th, 2010 (9:22 pm)Rooster,
I understand this is what you and Kurt think will happen, that the battery will recharge on ascent.
I think my main reason for being skeptical beyond the calcs I have posted is my Prius experience driving in mini-mountain terrain. The Prius weighs about 2900 lbs unloaded, and has a 70 kw ICE. When CS mode sets in, the battery stays depleted and the ICE revs high until the ascent is finished. There is not extra ICE power available to replete the battery. This will be doubly true for the 53kw/3800 pound Volt. Moreover, if the 53 kw is max ICE power, conversion losses will factor in also. On this last point though I wonder if Kurt is correct that 53 kw max is from the gen rather than the ICE.
+2
Aug 20th, 2010 (9:40 pm)You do realize that the 111 kW motor has a much higher output for short periods.
The 53 kW is the max power of the genset not the ICE part of the genset.
And yes LankKurt has described Mountain Mode correctly. The ICE comes on before the normal charge depletion point, which gives you a lower DOD so you have more battery power available for short periods.
-4
Aug 20th, 2010 (9:50 pm)Am I correct is saying that the Volt has one M/G, that accepts both battery and ICE energy inputs ? If so I do not understand why the M/G would take a 111 kw input from the battery, but only a 53 kw input from the ICE.
Aug 20th, 2010 (10:03 pm)Hey Lyle,
Wonder if you can find out:
-If 8 kwhrs is normally available after a charge, how much is available if you put the Volt into Mountain mode immediately after a full charging?
-What was the SOC at the bottom before they started the climb? Was it at the Mountain mode setpoint?
-How much was left in the battery when they reached the top?
-Was there any time during the climb when the battery shut down and they had to rely entirely on the generator?
-What were the average and peak RPM?
Aug 20th, 2010 (10:26 pm)See http://gm-volt.com/2010/05/05/chevy-volt-will-have-driver-selectable-mountain-mode/ for explaination of mountain mode. 55kw generator turned by ICE. 111kw drive motor turns wheels. Drive motor receives power from battery only in EV mode and from generator (ICE) and battery if required in CS mode.
+1
Aug 20th, 2010 (10:30 pm)Eric, just because the motor is 111kW, doesn’t mean it will always use all that. How many times in your car do you have your accelerator to the floor? I’m guessing rarely, if ever.
That’s why the concept of the generator being only 53kW, with the battery supplementing in the “pedal to the floor” scenarios, works so well. Since pedal to the floor scenarios don’t last long, it’s easy to take the borrowed energy and put it back in the battery, even though the ICE is “only” 53kW.
For argument’s sake, 53kW is roughly half of 111kW… My soon-to-be-obsolete combustion engine red lines at 7000RPM, but I can’t think of many driving scenarios when I’m running at even half that. I realize that RPM’s don’t directly equate to the amount of gas I’m burning/energy a car’s using, but I hope my comparison at least helps to conceptualize the Volt for you.
join thE REVolution
+1
Aug 20th, 2010 (10:44 pm)FWIW, I don’t think the Prius is designed to spend a lot of time putting energy from the ICE to the battery, is it? I didn’t think that was very efficient in a parallel hybrid design… Changing mechanical/ICE – electrical/battery – mechanical/wheels seems silly when you can just decrease RPM’s of the ICE.
The main function of the battery in a Prius is to capture regenerative braking energy, and use it as is efficient. As such, I don’t think it would ever be trying to actively add energy to the battery in even the slightest of strenuous driving situations, as that’s just not efficient in the case of the Prius.
The difference with the Volt is we’re talking either:
1) electrical (battery) – electrical (motor) – mechanical (wheels)
2) mechanical (ICE) – electrical (motor) – mechanical (wheels)
Since you’re always going to electrical, it’s probably more efficient at times to be dumping whatever extra from the ICE to the battery, rather than decreasing RPM’s, since there’s peak efficiency at certain RPM’s.
To me, that’s the difference here between the Volt and the Prius IRT the quoted post.
join thE REVolution
Aug 20th, 2010 (10:45 pm)LandKurt’s understanding of “mountain mode” is basically correct, EricLG. Go to this link on gm-volt.com to help yourself understand what it does:
http://gm-volt.com/2010/05/05/chevy-volt-will-have-driver-selectable-mountain-mode/
Happy trails to you ’til we meet again.
+2
Aug 20th, 2010 (10:48 pm)As soon as I read this I realized just how much you’re shooting from the hip.
I haven’t bothered with the rest of your posts. Not much credibility after that.
-3
Aug 20th, 2010 (11:07 pm)ClarksonCote,
Regen is actually a relatively minor component of the high mpg seen in the Prius; the greatest contributor is high ICE efficiency. This is accomplished (in very broad strokes) by
Atkinson engine having high BSFC at low power demands;
Interplay of the two M/G sets to keep engine load high;
and battery use when power demands are high.
Apparently, most of the energy flow to and from the battery is dictated by SOC first and foremost, driver power demands second, and ICE efficiency last.
Aug 20th, 2010 (11:12 pm)Early reviews are upbeat. Looking forward to more on the final interior accenting and texturing.
“First Impressions Are Promising” — Car and Driver
“The ride is a bit firmer than in a Prius, and its electric power steering is linear and well-weighted. This is in contrast to that of other Chevy vehicles (the Equinox, for instance), which tend to be numb in feel and overly light in effort. While we wouldn’t call the Volt fun to drive, it seems like one of the more involving among alternative-fuel and hybrid cars.” — Edmunds
“The car feels solid and planted on the road. There is minimal body lean in the tight corners. The low-rolling-resistance Goodyear tires created specifically for the Volt provide excellent grip.” — New York Times
“Those Volt skeptics out there are going to be badly embarrassed if they keep doubting the seriousness of this vehicle.” — Motor Trend
“Though the team is still fine-tuning the hardware and software, the Volt appears to be just as livable, comfortable and quick (and in sport mode much more so) as conventional hybrids on the road today.” — Popular Mechanics
“Communication through the steering wheel was direct and pleasantly hefty, and the brake pedal felt similarly deliberate and readable.” — Popular Mechanics
The interior is snazzy and futuristic, but thankfully its functionality doesn’t suffer for it.” -Edmunds
=D-Volt
-2
Aug 20th, 2010 (11:19 pm)“Atkinson engine having high BSFC at low power demands”
Typo, should be *low* BSFC …
-3
Aug 20th, 2010 (11:23 pm)0.7 * 0.7 = 49%
Your confusion is not my hip
Aug 20th, 2010 (11:49 pm)I am very interested in the Volt!
Your comment above about “CS MPG unless it is truly awful.” That is my point.
When one looks a the total MPG measurements for the other Hybrid cars… a truly awful VOLT MPG in CS mode makes it a harder call to buy the VOLT at a premium price.
One needs to realize if they plan to buy a VOLT “Plan B” will indeed be a major reason because of the expected longer distances that will be traveled when needed in a electric.
Dollars are dollars when it come to ones own funds and getting the best value for those dollars is very important no matter how fancy that “new technology”
Aug 20th, 2010 (11:50 pm)Gee I wish I knew they were in Colorado, I’d have check them out.
At least I know it will be ready for my mountain climbs if I finally get one. (Hope my 1995 honda holds out till they get to selling them in CO. )
Maybe there are six as the test various control algorithms (maybe with the help of their local battery expert at Univ. of Colorado at Colorado Springs. (http://www.eas.uccs.edu). One of our faculty is working with Faculty from Michigan on the Volt’s battery control. (see http://www.gazette.com/news/electric-57300-project-battery.html). Its cool to see the giant batteries being tested in the lab.. but would be more fun to help the test it on the road.. (if anyone from GM is reading this, maybe you need more CO test drivers. I volunteer
+2
Aug 20th, 2010 (11:56 pm)The problem is not your math, but your “If I remember correctly” figures. The curb weight of a current Prius is 3,042 lb and the Volt is 3,500 lb. That’s 15% heavier, not 30%. You’re also off on the relative power of the ICE engines.
+1
Aug 21st, 2010 (12:00 am)Re: #113 DonC
About free wheeling.. I am assuming when the poster was discussing “free wheeling” they would not have the regen mode available and the only way to slow down would be to use the brakes.
That is why the “brakes would melt” comment :+}
As most of us know in a conventional ICE vehicle the proper way to descend is to be in a lower gear and apply the brakes as needed. The brakes stay much cooler. my 2 cents
Aug 21st, 2010 (4:33 am)You caught me
Aug 21st, 2010 (7:07 am)I agree w/ the Prez. 75% of daily trips may be 40 miles would get e-mileage benefits but for those people the annual benefits are huge and Volt40′s can take advantage of this.
The idea that you would have to start with the 2011 Volt battery pack and add to it’s current physical size to make a longer range EREV is necessaeily accurate. GM is being cautious with this first gen battery and only using 50%. The second generation, already in testing will be longer lived and more energy dense. In all likelihood, the CD window will be opened up to 60-70 in the coming years. This, along with higher energy density and smaller genset packaging, would actually allow a longer e-range and a 5th seat. This is not to say they shouldn’t continue to offer an EREV40. They certainly should as well as a lower cost, shorter range option. Hopefully batteries can improve enough and in relatively short order so that liquid cooling is no longer needed. Even if Nissan has screwed up and their first gen air cooled battrries don’t last as they expect, the tech must still be close. Air cooling takes a decent amount of cost out and, more importantly, makes modularity more practical.
Battery modularity and traction power options will really help EREVs (and BEVs) push into the fastest part of the market pyramid.
Aug 21st, 2010 (7:16 am)hey ericLG i think i speak for everone when i say, f*ck off mate, sick of your negative troll rubbish, learn more about this before you go talking sh1t
JMHO
stuey in OZ
Aug 21st, 2010 (7:16 am)Wrong. That’s not what I’m saying or assuming or even what I said. Both batteries have A LOT of capacity to accept regen. In my very first post I said that even if the Volt was at 50% SOC before its descent, that it would have the capacity to accept 4.8 kWh of energy…
That said, the Volt has enough capacity to descend Pikes Peak 2-3 times before the battery was topped off.
One correction on my previous posts. Max regen. is characterized by these equations. I was going from memory before. SOC of the battery only becomes a factor when the battery reaches a higher state of charge, at which point the charge rate must be reduced.
Max. regen power is based on these equations:
deltaV = Open Circuit Voltage – V(max) of Power electronics
I = deltaV/R = (OCV-Vmax) / R
P = Vmax X Imax = Vmax X (Vmax-OCV) / R
So, the ability to accept regen will depend on the battery chemistry and the max voltage of the charge controller. I don’t think we have enough info. to compare the Volt and Leaf in this way (yet).
+1
Aug 21st, 2010 (7:18 am)“Those Volt skeptics out there are going to be badly embarrassed if they keep doubting the seriousness of this vehicle.” — Motor Trend
“Those Volt skeptics out there are going to be badly embarrassed if they keep doubting the seriousness of this vehicle.” — Motor Trend
“Those Volt skeptics out there are going to be badly embarrassed if they keep doubting the seriousness of this vehicle.” — Motor Trend
Didn’t realize Motor Trend was a Volt fanboi. What are all of the haters going to hate on now? Not much left. I can see the closed mind, with clenched eyes repeating to themselves: “there’s no place like <35mpg, there's no place like <35mpg, there's…"
-1
Aug 21st, 2010 (8:29 am)That is why I wrote “if I remember correctly.”
I was actually thinking about the G2 Prius, but mixed and matched specs from it with the G3. Its ICE is 57 kw, while the G3 ICE is 73 kw.
I stand corrected on the Volt weight. I thought it was 3800.
So the math stands at (53*2900)/(57*3500) = 77% Volt power climbing relative to the G2 Prius.
-1
Aug 21st, 2010 (8:53 am)How about:
41,000 lol!
41,000 lol!
41,000 lol!
Not the same thing as hate perhaps, but I imagine it gets under Volt fanboi skins just the same. And there is always the old Prius FUD to throw on a slow day, e.g: Post in 10 years when the Volt has demonstrated a little reliability.
+1
Aug 21st, 2010 (9:05 am)ericLG, umm your a knob……also no-one cares about your opinons
Aug 21st, 2010 (10:04 am)The Volt transaxle contains M/G 1 (aka, the generator) and M/G 2 (aka the drive motor). M/G 1 is driven by the ICE and can provide 53 KW of power to the battery and/or M/G 2. M/G2 provides up to 110 KWh of power to the drive wheels. In EV (Electric Vehicle) mode, all the power available to M/G 2 is supplied by the battery. In CS (Charge Sustaining) mode, up to 53 KW’s of the power available to M/G 2 is supplied by M/G 1, and the difference is supplied by the battery. In CS mode, when the power demanded by M/G 2 is less than the power provided by M/G 1, the is used to recharge the battery and increase it’s state of charge.
The battery state of charge (SOC) will fluctuate between the absolute minimum SOC allowed (around 20-25%) and an upper bound, which is higher in mountain mode. Should the battery state of charge reach the lower limit, and M/G 2 demands more than 53 KWs of power, it will be power limited to 53 KW (what can be supplied by M/G 1) until the battery SOC can recover above the lower limit — this is to protect the battery. The testing on Pikes Peak is to ensure this power limited condition doesn’t happen, and it didn’t.
Aug 21st, 2010 (10:14 am)Only if you reach the min allowable battery SOC condition…then S/W will kick in to protect the battery. Mountain Mode and continuous S/W fine tuning are to ensure you never reach the power limited condition, even when climbing Pikes Peak at legal speeds.
Of course, all bets are off if you keep the Volt floored all the way up Pike’s Peak. (That by the way is not recommended, as you’d likely kill yourself first or someone else).
Aug 21st, 2010 (2:02 pm)Indeed!
Aug 21st, 2010 (2:54 pm)Rooster, thanks.
Were technical details released about the Pike’s peak climb ? Specifically SOC, speed, and power demand trends ?
I agree with your comment that my relative power calc only holds true when both cars have no battery charge to draw from.
Aug 21st, 2010 (3:46 pm)I am wondering about ICE efficiency in the Volt. What load is the ICE working against, and how does that load vary ?
Aug 21st, 2010 (4:31 pm)$350/mo…neeext
Aug 21st, 2010 (4:42 pm)lol! Not a bad answer
Let’s see though, compared to a nice reliable HV that will run 10 – 20 years, we have a range of
(350*10*12) + 2500*3 to (350*20*12) + 2500*7, or
$49,500 – $101,500
Or perhaps more in keeping with the “own 3 years and change cars mentality:” Buy a nice used HV for $12k, use 3 years and sell for around $9k. Spend $3k over 3 years rather than $15,100
Aug 22nd, 2010 (7:55 am)I disagree with these equations. The battery (and associated power electronics) cannot be modeled by a simple fixed resistance. If OCV were sufficiently high it could destroy the power electronics, however the manufacturers must have dealt with this problem or the power electronics would certainly fail the first time the car entered re-gen from high speed. The OCV is irrelevant since as soon as the motor is connected to the battery circuit, it will drop to a voltage a few volts above the battery voltage, I will call this the Closed Circuit Voltage and claim this is the only one that counts. The current will be determined by the CCV and effective battery resistance. This “effective resistance” will be controlled by the electronics and will be under driver control by the gas pedal or possibly the brake pedal as the amount of re-gen desired. Maximum re-gen will be determined by the size and capability of the motor so for the Volt cannot exceed 150kW, another limiting factor is traction, as maximum re-gen braking could induce skidding at high speeds or by wet roads. The maximum charge rate and discharge rate of batteries is the same, so if a battery can supply 150 kW of power, it can also absorb 150 kW. Bottom line is the battery is not the limiting factor.
Aug 22nd, 2010 (10:14 am)No, I haven’t seen the specifics of the Volt testing on Pikes Peak from GM. What we do know is they are testing multiple vehicles at the same time, so we can surmise that they are testing a statistical spread of initial conditions…including starting the Pikes Peak climb in normal mode while in CS mode. To date, GM has stated they have been pleased with the performance of the car.
They have also test the Volt in the mountains of West Virginia, Maryland and Pennsylvania on the interstate (i.e., I-68, I-79) and they reported the Volt performed fine. Having just driven I-68 last week, I can attest that this road has some decent grades (6% for 8 miles with a posted speed limit of 65 & 70 MPH). For example, even my Enclave (which has a 288HP directed injected VVT engine) had to kick down and turn 3400 RPM to maintain 70-75 MPH up the grade. So the fact that the ICE in the Volt will have to do the same (turn at a higher RPM) to provide adequate power isn’t anything new. The main difference is because of the battery, the Volt’s ICE only has to provide the average power required–the battery serves to smooth out the power demand peaks and valleys.
Aug 22nd, 2010 (10:37 am)The only load on the ICE is the generator (M/G 1), there is no mechanical connection between M/G 1 and the drive wheels. This has been confirmed by our GM insider in the forums, who been sharing with us what he can without giving away proprietary information. Because the ICE is disconnected from the wheels, it can run at discrete RPMs that maximize efficiency for the given power requirement, and minimize noise, vibration and harshness (NVH). GM has really been focusing on minimizing NVH in CS mode, but don’t expect to not hear the ICE while traveling at 75 MPH up a 6% incline.
Aug 22nd, 2010 (10:42 am)It will be interesting to see what the residual value on the Volt will be after the 3 year lease.
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Aug 22nd, 2010 (12:29 pm)Correct me if I am wrong, that efficiency is a function of power, rpm and load.
Aug 22nd, 2010 (3:47 pm)Correct, and because the Volt has a 16 KWh battery, it can handle anything the the Generator can put out, thus the S/W can always run the ICE/Genset at max efficiency for the given power demand. If the max efficiency point is higher than the power demand, excess power can be used to recharge the battery. Should the battery SOC reach the upper limit in SC mode, the ICE can shut down. Lot of options, GM is fine tuning the control S/W now.
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Aug 22nd, 2010 (4:33 pm)I’m not clear that having a place to dump energy is the same as being able to dump it efficiently. I keep imagining the ICE connected to the generator by an axle, and am wondering if the counter torque on the axle is variable and controllable to keep the ICE at its best BSFC.
Does that even make any sense ?
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Aug 22nd, 2010 (8:43 pm)Are you basically saying put a CVT between the ICE and M/G 1 (generator)? Maybe, but I think it would add too much complexity/cost. GM is being tight lipped on the Volt’s drive train configuration, we’ve been speculating about it on the forum since July. You can read about it at the link below, play close attention to WOT’s posts.
http://gm-volt.com/forum/showthread.php?t=4783
Cheers!
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Aug 22nd, 2010 (8:52 pm)Indeed, the Prius varies load on the ICE by playing with two MG’s that, along with the ICE, are connected at a planetary gear. I am way out of my engineering league here, so was asking if the Volt drivetrain has some mechanism to vary load although I am unable to guess what it might be.
Thanks for the interesting discussion !
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Aug 22nd, 2010 (9:36 pm)I was just counting up components for the Prius and Volt drivetrains:
Prius has an ICE, two MG units, and one planetary gear. I read the other day that the Prius PHV has a clutch.
Volt has an ICE, two MG units, at least one planetary gear, and a clutch.
We should probably not be surprised that the designs are approaching each other.
The difference of course is that the Volt ICE is presumed to have a single, direct connecton to the smaller MG, which is why I cannot wrap my brain around the ICE load solution.
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Aug 22nd, 2010 (9:54 pm)Now I am talking to myself ..
Maybe the answer is that the Volt ICE only has one power output level, and the ICE load has been designed to match it. I read the other day that the ICE will charge the battery in CS mode up to some predetermined level, then shut off until needed again in a cycle until the battery is recharged. That would be consistent with a single power level output generator.
The only downside I can think of to it is that it means a lot of the ICE energy production goes through the conversion steps of MG2 – MG1 – Inverter – Battery_in – Battery_out – Inverter – MG1, and whatever gearing is interspersed.
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