Aug 24

The Volt in Cold Weather

 

By Bill Destler

With summer drawing to an end and the cold days of winter just a few months away, I thought it might be a good time to discuss how lower temperatures and winter weather in general affect Volt range and efficiency.

All gas-powered cars get lower gas mileage in cold weather. My Toyota Prius, for example, gets about 48 mpg in the summer but only 38-40 mpg in the cold Rochester, NY, winters. The reasons gas-powered cars get lower gas mileage in cold weather include increased friction from thicker motor oil, transmission fluid, power steering fluid, and differential gear oil and increased rolling resistance as we slog through snow and sleet, especially if we forget to maintain tire pressure between 35-40 psi, since without adding air, tire pressure goes down by 1-2 psi for every 10 degrees the outside temperature goes down. Finally, gasoline engines operate optimally at a specific temperature, and during warm up periods they are simply not as efficient.


Burr! Cold Volt.

Now the Volt is subject to many of these effects, especially when operating in charge-sustaining (gas consuming) mode. But in all-electric mode, several other factors are at play. First, let’s consider battery performance as a function of temperature. If you charge any battery in a heated garage and then take it outside into freezing weather, the temperature of the battery will quickly be reduced to the ambient outside temperature and the electrochemical reactions that provide the current will occur at a slower rate. Thus the battery will seem to have lost capacity since as it is used the current will decline from a lower starting point and the battery will quickly fail to provide enough current at a given voltage to perform its function. Interestingly, if you then move the same battery back into the heated garage, the battery will recover as it warms and you can ultimately draw almost all of the original charge power out of the battery before you have to recharge it. So cold weather doesn’t really reduce battery efficiency in the sense that you put 10 kwh in and get only 6 kwh back. If you warm the battery back up to room temperature, you can get the missing 4 kwh from the battery again, or when you recharge it you will only need to provide 6 kwh to reach full charge again.

Efficiency aside, however, in an electric vehicle a cold battery will deliver less range than a room-temperature battery because of the lower electrochemical reaction rate. GM has addressed this issue in the Volt by using a sophisticated battery temperature control system aimed at keeping the battery at a good operating temperature. I do not know what the acceptable temperature range for the Volt’s battery has been set at, except that it has to be above 32 degrees F and below 100 degrees F to adequately protect any lithium-based battery and extend its life. But everything has a price, and the energy consumed to maintain the battery temperature in cold weather has to come from somewhere, so winter range is reduced. This effect is most severe if you don’t keep your Volt in a garage and don’t plug in the charger when you are not driving the car, since the battery temperature control system needs power from somewhere and if it took the power from the battery then all-electric range would be reduced even further just to keep the battery warm when the car is not being driven. In fact, it appears that GM has chosen to not drain the battery for battery temperature maintenance in cold weather when the car is idle and not connected to a charging station, which means that the system has to consume even more energy once you start driving to get the battery temperature up to a good operating point. At very low temperatures, the Volt will start the gasoline engine to warm up the battery more quickly, but this consumes energy of a different sort.

In fact, many of us have seen all-electric range of between 45-50 miles in the spring and summer reduced to 25-30 miles in the winter. Is that reduction all due to the battery temperature control system? No. A majority of the energy is lost in the human temperature control system, i.e. the cabin heater. In a gas-powered car, much of the energy in the gasoline that could be used to drive the wheels is lost as heat radiating from the engine, so providing heat for passengers is a simple matter of diverting some of that heat into the passenger cabin. An electric drivetrain car is much more efficient than one using a gas-powered drivetrain, so very little heat is generated by the electric motor and heat for passenger comfort has to be provided by passing electrical current from the battery through a heating element as you would in an electric stove. This is not a disadvantage of an electric vehicle, but rather a result of its higher operating efficiency. If we want cabin heat, we must use some of our battery energy to provide it.

These two winter energy consumers, the battery temperature management system and the cabin heater, are the primary reasons for the observed reduced range in cold weather. So is there anything we can do about it? For some of us, the answer is yes.

If we keep our car in a heated garage and keep it plugged into the charger when we are not using it both at home and at work, we will be using home heating systems or grid power to maintain the battery temperature and the cabin temperature while we are not driving. Starting both systems off at the right temperature doesn’t mean we won’t consume battery power to maintain them while we are driving, but it will save battery energy and extend our winter all-electric range. In an unheated garage, you can pre-heat the cabin using grid power by remotely starting the Volt (and the heater) before you leave for work (or from work if you can plug in there). One strategy to consider would be to preheat the cabin while connected to the charging station by setting the climate to “Comfort”, turning off “Auto” temperature control and turning up both the temperature and the fan. Then when you start driving you can turn the system back to “Eco” and “auto” to conserve energy and range. But remember, there is no free lunch. The extended winter range has to be paid for in additional electricity consumption while you are plugged in.

It’s probably a good idea to also limit your use of Sport mode in the winter, especially if your Volt has been standing idle in the cold and not connected to a charging station. And the use of L mode while driving is also a good idea, since it provides added braking under slippery conditions and regenerates power more effectively than D mode.

Volt engineers have found that heated seats use up less energy than does heating the cabin, so using the seats (if you have them) in cold weather and limiting cabin heating to the extent to which you are comfortable is another good idea.


A fleet of frozen Volts.

In charge-sustaining mode, the use of a low-viscosity synthetic motor oil, such as Mobil 1, in the Volt’s gasoline-powered generator would probably improve gas mileage because such oils flow much more easily at low temperatures. Happily, the Volt will divert heat from the gas engine to the cabin in this mode, so passenger heating is not as much of an issue in this mode.

It might be interesting to see if Mountain mode, which operates the gas generator more and therefore makes some gas engine heat available for cabin heating, might also be used intermittently during the winter to extend all-electric range.

I would be interested to hear of other strategies for cold-weather Volt operation. It would also be helpful to get reports from users on what all-electric range they achieve at below-freezing temperatures.

This entry was posted on Wednesday, August 24th, 2011 at 5:55 am and is filed under General. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.

COMMENTS: 63


  1. 1
    Bob_Livonia

    +1

     

    Vote -1 Vote +1

    Bob_Livonia
     Says

     

    Aug 24th, 2011 (6:24 am)

    I can definitely vouch for the fact that Li-ion batteries lose their capacity in the cold but they regain it when warmed up (no energy loss). I take my cell phone with me cross-country skiing (mainly to track my distance and total elevation rise using its GPS), and I am out for hours at a time when the temperature is below 10 degrees F. I take a second cell phone battery with me. But even after a battery causes the phone to shut down, when it is warmed up, it again has plenty of charge.


  2. 2
    Roy_H

    +1

     

    Vote -1 Vote +1

    Roy_H
     Says

     

    Aug 24th, 2011 (6:28 am)

    A very good article on cold weather performance. However I feel compelled to nit-pick at one detail.

    “This effect is most severe if you don’t keep your Volt in a garage and don’t plug in the charger when you are not driving the car, since the battery temperature control system needs power from somewhere and if it took the power from the battery then all-electric range would be reduced even further just to keep the battery warm when the car is not being driven. In fact, it appears that GM has chosen to not drain the battery for battery temperature maintenance in cold weather when the car is idle and not connected to a charging station, which means that the system has to consume even more energy once you start driving to get the battery temperature up to a good operating point.”

    The way this is written seems to imply that it would be more efficient to keep the battery warm when the car is not in use. This is not true. But using grid energy to pre-heat the car and battery is certainly desirable to get the most AER.


  3. 3
    Loboc

    +2

     

    Vote -1 Vote +1

    Loboc
     Says

     

    Aug 24th, 2011 (6:41 am)

    It’s pretty strange to think about cold weather when we are having record-breaking heat here in Texas. :)

    When you do a ‘remote start’ and Volt is on grid power, what happens? Does it ever start the ICE for any reason while on grid power?


  4. 4
    Tom W

    +1

     

    Vote -1 Vote +1

    Tom W
     Says

     

    Aug 24th, 2011 (7:49 am)

    If you had programmed to pre condition the car lets say 7AM, but there was a power failure, would the ICE start up in the garage and create a life threatening condition?

    I would hope there are no conditions where the ice would start up without a person in the car.


  5. 5
    Tim Hart

     

    Vote -1 Vote +1

    Tim Hart
     Says

     

    Aug 24th, 2011 (8:20 am)

    Thanks Bill for a good reminder of the issues for driving in the winter months. I’ll be getting our Volt about the time cold weather sets in so will miss the great summertime AER. Darn!


  6. 6
    Nelson

    +2

     

    Vote -1 Vote +1

    Nelson
     Says

     

    Aug 24th, 2011 (8:45 am)

    Remote start will automatically shut off after 10 minutes unless a time extension is done. While the remote start is active, the parking lamps will turn on and remain on. After entering the vehicle during a remote start, press the POWER O button on the center stack with the brake pedal applied to operate as normal. The remote start can be initiated two separate times between driving. For each remote start, the passenger compartment will be heated or cooled for 10 minutes.
    Chapter 2-9, Page 45. Volt Owner Manual

    NPNS!
    Volt#671


  7. 7
    pjkPA

    +3

     

    Vote -1 Vote +1

    pjkPA
     Says

     

    Aug 24th, 2011 (9:53 am)

    A local TV station reported that Prius owners in our area said they are getting 26mpg in the winter months in our area. The small engine and battery don’t like the snow .. cold… and hills of our area. My Buick gets 1 or 2 mpg less in the winter… 23-24 mpg in the winter… that’s in a very quiet smooth 200hp Buick … the Plug in Volt is a much better technology for our area since the commutes are about 10-15 miles each way for most commuters which means they will still be using mostly electric driving in the Volt .. even in the winter months.


  8. 8
    Loboc

     

    Vote -1 Vote +1

    Loboc
     Says

     

    Aug 24th, 2011 (9:59 am)

    Tom W: I would hope there are no conditions where the ice would start up without a person in the car.

    My 2009 Impala will remote-start in the garage. How’s it going to know it’s in a garage?

    My question @3 is: Does the ICE ever start when on grid power? In other words, if there is insufficient battery conditioning coming from the grid AND the user has pressed remote start, does the ICE come on to assist?

    Also, do you need to remove the charging cord to start the car (using the dash button, not the remote), or, does it allow you to start but you can’t engage ‘drive’ until the cord is unplugged. Is there some kind of visual or audio, or does it just not go into drive.

    These kinds of details are not in the manual.


  9. 9
    Slapshot28

     

    Vote -1 Vote +1

    Slapshot28
     Says

     

    Aug 24th, 2011 (9:59 am)

    One notion where some data would help is this statement: “If you charge any battery in a heated garage and then take it outside into freezing weather, the temperature of the battery will quickly be reduced to the ambient outside temperature.”

    I guess is depends on your definition of “quickly” but I think we are talking many hours here, even a day or longer. The Volt’s battery is quite massive from a heat capacity standpoint, and is well-insulated.

    Regardless, keeping the Volt in a somewhat warm garage will make a huge difference, no question. I think Consumer Reports proved this when they got only 20 miles of battery range after cold-soaking the Volt overnight outside in sub-zero temperatures. In contrast, my lowest range last winter was 28 miles, using an attached (but not heated) garage.

    One last point relates to comments above regarding Remote Start and turning on the ICE. There are a number of extensive and energetic threads on the Forum here regarding this topic. In my opinion, GM engineers are extremely safety-conscious, no worries. If you disagree, please read the forum posts before launching into a diatribe. For example, knowledgeable members here point out that modern catalytic converters eliminate most carbon monoxide generation, especially in just 10 minutes (the Remote Start time limit). Also, many of today’s ICE-based cars include the very same Remote Start capability as the Volt, which of course for an ICE-based car immediately starts the engine.


  10. 10
    PatsVolt

     

    Vote -1 Vote +1

    PatsVolt
     Says

     

    Aug 24th, 2011 (10:02 am)

    One thing that was not discused is the efficiency of the insulation around the battery. It is my understanding that it is very good, though we do not have any charts to show what the insulation characterisitcs are. Then the the idea came to me that if you are in cold weather it would be a good idea to delay chatrging until the last minute so that it is close to the time of departure. Depending on what charge level one is using, setting the charge delay so that it ends prior to departure will make sure the battery is warm for the drive. I know that the battery is conditionded during charging, and is most noticable during hot weather when the airconditioning compressor turns on to cool the battery. I will be trying this technique this winter.


  11. 11
    Slapshot28

    +2

     

    Vote -1 Vote +1

    Slapshot28
     Says

     

    Aug 24th, 2011 (10:09 am)

    Loboc,

    Yes, the ICE can come on even if the Volt is plugged in. I can only speak for 120 V charging; however, I know it happens when my garage is very cold, and the Volt has been plugged in all night and still is plugged in. With 240 V charging, there may be enough “juice” to keep the battery warm and avoid the ICE from coming on during a Remote Start.

    I think it is important to make sure everyone understands that the Volt’s ICE NEVER will turn on by itself, unattended and unprompted, under any conditions, period. The ICE requires some sort of user prompt, like Remote Start, open the hood while the car is on, etc.

    As to your second question, you can always start the Volt using the blue center console button, even if the Volt is plugged in. But you cannot get it out of Park until you unplug it, and the Volt tells you this right on the main screen, behind the steering wheel. (I hope my memory is right, because my Volt is 500 miles away from me right now…)


  12. 12
    George S. Bower

     

    Vote -1 Vote +1

    George S. Bower
     Says

     

    Aug 24th, 2011 (10:26 am)

    Bill,
    Another good article!

    ChrisC put together a very good table relative to this subject. Contained here:

    http://gm-volt.com/forum/showthread.php?5243-Volt-thermal-management-system-temperature-band/page13

    It will show you what the Volt’s TMS does as a function of battery temp for 3 conditions: 1) Volt parked and plugged in 2) Volt parked and NOT plugged in and 3) Volt is powered on (ie being driven)

    The interesting thing to note is that, if the battery temp is between 25 and 68 F the TMS DOES NOT heat the battery.

    Between -13F and 25F and you are plugged in the TMS WILL heat the battery (but only untill the battery temp gets to 25 F).

    Interesting things happen below -13F!!

    You MUST plugin to warm up the battery above -13F in order to start the car.


  13. 13
    George S. Bower

     

    Vote -1 Vote +1

    George S. Bower
     Says

     

    Aug 24th, 2011 (10:32 am)

    PatsVolt:
    Then the the idea came to me that if you are in cold weather it would be a good idea to delay chatrging until the last minute so that it is close to the time of departure

    I had the same question and asked it in the forum but I never got an answer.
    I would think that would be an effective way to help things out.

    Any owners have an answer on this??


  14. 14
    flmark

    +3

     

    Vote -1 Vote +1

    flmark
     Says

     

    Aug 24th, 2011 (10:50 am)

    I bring this up mostly in jest, but maybe someone could take this and run with it to develop a new line of clothing for EVs (but only if automotive seat makers ever embrace the idea). Today, a new range is being delivered to my NY home. After experiencing induction cooking in FL (and a convection oven, as well), my wife has been miserably frustrated with the electric range that came with this home purchase. So the range delivered today has an induction cooking surface.

    Induction cooking is the most efficient method of cooking; nearly twice as much as alternatives (including natural gas). The cooking surface does not get hot; instead, a magnet field interacts with the pan to make IT hot instead.

    The advent of EVs has auto manufacturers discussing the use of direct seat heating as a standard feature; it is fairly cheap to install seat heaters and they are much more efficient at heating up people than blowing hot air around the cabin. Of course, these heaters work like a conventional electric cooktop, using electrical resistance. And then, this ‘cooking’ must travel through multiple clothing layers to accomplish anything.

    Now imagine a scenario with induction coils in the seat, instead of resistive elements…and vehicle occupants wearing long underwear embedded with metallic fibers that respond to induction. Maybe I should patent the idea. If not practical, certainly amusing if you think about a guest in the vehicle (who didn’t wear the proper undergarments). I guess in this case, you could have seat covers which respond to induction that you could utilize when necessary.


  15. 15
    George S. Bower

     

    Vote -1 Vote +1

    George S. Bower
     Says

     

    Aug 24th, 2011 (10:53 am)

    PatsVolt:
    One thing that was not discused is the efficiency of the insulation around the battery.It is my understanding that it is very good, though we do not have any charts to show what the insulation characterisitcs are.

    What we need is a readout on battery temperature.
    The MDI would do that.

    http://gm-volt.com/forum/showthread.php?5328-Volt-Diagnostic-Tool


  16. 16
    Jackson

     

    Vote -1 Vote +1

    Jackson
     Says

     

    Aug 24th, 2011 (11:14 am)

    “An electric drivetrain car is much more efficient than one using a gas-powered drivetrain, so very little heat is generated by the electric motor and heat for passenger comfort has to be provided by passing electrical current from the battery through a heating element as you would in an electric stove.”

    In the early days here, when no actual Volt was available for inspection, many of us speculated that the car’s A/C might double as a heat pump (I know, this would be pointless in extremely cold weather; but a lot of us live in more temperate climes). I believe many of us were disappointed to hear of the resistance heater (and that we still hope that the more efficient heat pump will be a future enhancement).

    Unlike an air conditioner for a gas car, there is no need for the Volt’s compressor to be turned by a belt from the rotation of an engine; it is likely sealed with it’s own electric motor into it’s coolant loop like the unit in a refrigerator or house A/C. It should be capable of constant-speed operation, allowing the compressor to be smaller than an ICE car’s (which must deliver usable cooling even when the engine is idling). This is all good news for cabin-cooling efficiency. I would think that exploiting this system for heating (for temps in the 50 – 30 F range) would be a no-brainer (and all that would be needed for 95+ % of cabin heating in Atlanta, for instance).


  17. 17
    DonC

    +1

     

    Vote -1 Vote +1

    DonC
     Says

     

    Aug 24th, 2011 (11:19 am)

    Great article Bill. Lots of good information!

    Slapshot28: One notion where some data would help is this statement: “If you charge any battery in a heated garage and then take it outside into freezing weather, the temperature of the battery will quickly be reduced to the ambient outside temperature.”

    This stuck out for me. My guess is that the battery won’t go go to the ambient temperature at all much less quickly. First, the battery is well insulated. I think they parked the Volt in the freezer overnight at -30F or something and the pack was still above 32F or 0F or something the next morning. Obviously no amount of insulation will keep the temperature from dropping, just not quickly. Second the chemical reaction is exothermic so when you’re using the battery you should be generating heat.


  18. 18
    DonC

     

    Vote -1 Vote +1

    DonC
     Says

     

    Aug 24th, 2011 (11:27 am)

    Jackson: This is all good news for cabin-cooling efficiency. I would think that exploiting this system for heating in temps in the 50 – 30 F range would be a no-brainer (and all that would be needed for 95+ % of cabin heating in Atlanta, for instance).

    Just two words for you Jackson: Heated Seats (LOL)

    I believe the heating systems for the battery and the cabin are separate but the cooling systems are not. (Have to go back to WOT’s article on heating/cooling to confirm). For cooling, if high battery temperatures require that the cooling system engage, the system will also cool the cabin even if the cabin AC is turned off. That surprised some people. They’d be driving with the air conditioning off when suddenly the air flow would turn nice and frosty.


  19. 19
    BLIND GUY

    +3

     

    Vote -1 Vote +1

    BLIND GUY
     Says

     

    Aug 24th, 2011 (11:32 am)

    #14 FLMark Now imagine a scenario with induction coils in the seat, instead of resistive elements…and vehicle occupants wearing long underwear embedded with metallic fibers that respond to induction. Maybe I should patent the idea.

    Interesting idea but wouldn’t it be just as efficient to wear long underwear embedded with heating elements that can be plugged into aux. outlet? I think some motorcycle riders have something like this.


  20. 20
    Noel Park

     

    Vote -1 Vote +1

    Noel Park
     Says

     

    Aug 24th, 2011 (11:40 am)

    A non-issue here in sunny SoCal, I’m happy to say. although I did order the heated seats, just in case.

    The motorcycle guys use heated gloves, vests, and I think even socks or boots that plug into the bike’s charging system. There can’t be much of a power draw if a bike system can drive them. Plug ‘em in the Volt’s cigarette lighter. Sorry, convenience outlet.

    flmark: I bring this up mostly in jest, but maybe someone could take this and run with it to develop a new line of clothing for EVs

    So, to build off of flmark’s idea, this stuff actually exists already. While not as sexy as induction heating or whatever, it has the advantage of being off the shelf/catalog. Maybe there might actually be some applicability for you poor souls in the great white north, LOL.


  21. 21
    Noel Park

     

    Vote -1 Vote +1

    Noel Park
     Says

     

    Aug 24th, 2011 (11:42 am)

    BLIND GUY: I think some motorcycle riders have something like this.

    #19

    Beat me to it, LOL. +1


  22. 22
    BLIND GUY

     

    Vote -1 Vote +1

    BLIND GUY
     Says

     

    Aug 24th, 2011 (11:57 am)

    It sounds like very cold weather jumpsuits with Lithium-ion battery back-up embedded in suit might be a good option for keeping warm in extreme cold weather. Easy to put on over clothes and has portable battery for constant warmth.


  23. 23
    Jackson

     

    Vote -1 Vote +1

    Jackson
     Says

     

    Aug 24th, 2011 (12:06 pm)

    BLIND GUY:
    It sounds like very cold weather jumpsuits with Lithium-ion battery back-up embedded in suit might be a good option for keeping warm in extreme cold weather.Easy to put on over clothes and has portable battery for constant warmth.

    An electric jumpsuit you can plug in after you take it off indoors; yeah, I think that’s a good idea. And not just for EV jockeys. As a Southerner, I have a hard time imagining a Northern winter without a friggin’ Space Suit. Add a helmet to your jumpsuit, and a gizmo to heat the air in it, and I might come visit. Maybe.


  24. 24
    Rashiid Amul

    +1

     

    Vote -1 Vote +1

    Rashiid Amul
     Says

     

    Aug 24th, 2011 (12:06 pm)

    Bill Destler,

    This is an excellent article. Thanks for posting it.


  25. 25
    George S. Bower

     

    Vote -1 Vote +1

    George S. Bower
     Says

     

    Aug 24th, 2011 (12:13 pm)

    Jackson:

    I would think that exploiting this system for heating (for temps in the 50 – 30 F range) would be a no-brainer (and all that would be needed for 95+ % of cabin heating in Atlanta, for instance).

    Jackson,
    If you look at ChrisC’s table, the TMS takes no action in the heating department until below 25F battery temp and the heat pump probably wouldn’t work very well there.


  26. 26
    George S. Bower

     

    Vote -1 Vote +1

    George S. Bower
     Says

     

    Aug 24th, 2011 (12:18 pm)

    BLIND GUY:
    It sounds like very cold weather jumpsuits with Lithium-ion battery back-up embedded in suit might be a good option for keeping warm in extreme cold weather.Easy to put on over clothes and has portable battery for constant warmth.

    Good idea but I doubt many people would want to go to the effort. It’s a lot easier to use the seats or the cabin heat. That’s why they are in a car and NOT on a motorcycle!


  27. 27
    Jackson

     

    Vote -1 Vote +1

    Jackson
     Says

     

    Aug 24th, 2011 (12:26 pm)

    George S. Bower: If you look at ChrisC’s table, the TMS takes no action in the heating department until below 25F battery temp and the heat pump probably wouldn’t work very well there.

    I’m not talking about pack temperature. The TMS manages heating for the battery, not the cabin. The cabin temp is determined by a finger on a button. Yes, you’d still need a resistive element for the cabin below 30 – 40 degrees because of the limitations of heat pumps; and regardless of what the TMS does. (If the engine comes on, you don’t need a heat pump or an element for the cabin).


  28. 28
    Loboc

     

    Vote -1 Vote +1

    Loboc
     Says

     

    Aug 24th, 2011 (12:26 pm)

    BLIND GUY:
    It sounds like very cold weather jumpsuits with Lithium-ion battery back-up embedded in suit might be a good option for keeping warm in extreme cold weather.Easy to put on over clothes and has portable battery for constant warmth.

    Don’t even go there. I can see the Cavuto piece now. ..

    “Poor heater in Volt forces owners to use electric long-johns. ..”


  29. 29
    Mark Z

    +1

     

    Vote -1 Vote +1

    Mark Z
     Says

     

    Aug 24th, 2011 (12:31 pm)

    Cool topic. I will miss getting full battery range this winter. The EV range was less during Southern California winter nights 20 miles from the coast.


  30. 30
    Jackson

    +1

     

    Vote -1 Vote +1

    Jackson
     Says

     

    Aug 24th, 2011 (12:33 pm)

    Mark Z: Cool topic.

    I see what you did there. :-P

    … and I approve …


  31. 31
    Bill Destler

     

    Vote -1 Vote +1

    Bill Destler
     Says

     

    Aug 24th, 2011 (12:50 pm)

    George S. Bower,

    This is exactly the data I was looking for, but couldn’t find. Now if we can just get data on how effective the battery pack’s insulation is, we would know enough to draw firm conclusions as to when and under what conditions range will be seriously degraded. We do know, of course, that range is reduced significantly when operating below the freezing point, so the insulation can’t be perfect.


  32. 32
    Loboc

     

    Vote -1 Vote +1

    Loboc
     Says

     

    Aug 24th, 2011 (12:53 pm)

    Mark Z: Cool topic. I will miss getting full battery range this winter. The EV range was less during Southern California winter nights 20 miles from the coast.

    What’d it get down to? Like 67F. Brrrrr…


  33. 33
    Noel Park

     

    Vote -1 Vote +1

    Noel Park
     Says

     

    Aug 24th, 2011 (12:53 pm)

    George S. Bower: Good idea but I doubt many people would want to go to the effort. It’s a lot easier to use the seats or the cabin heat. That’s why they are in a car and NOT on a motorcycle!

    #26

    Well I dunno, there are some pretty serious hypermilers here, LOL. I bet electric gloves and a vest draw a LOT less current than heated seats. You might squeeze out a whole additional mile of AER, hahaha.


  34. 34
    Noel Park

    +1

     

    Vote -1 Vote +1

    Noel Park
     Says

     

    Aug 24th, 2011 (12:55 pm)

    Mark Z: Cool topic.

    #29

    No pun intended, of course. Tres drole! +1


  35. 35
    Noel Park

    +1

     

    Vote -1 Vote +1

    Noel Park
     Says

     

    Aug 24th, 2011 (12:58 pm)

    Loboc: What’d it get down to? Like 67F. Brrrrr…

    #32

    Hey, we saw 40F here a couple of times this winter. As I said, things are tough here.


  36. 36
    George S. Bower

     

    Vote -1 Vote +1

    George S. Bower
     Says

     

    Aug 24th, 2011 (1:22 pm)

    Bill Destler:
    George S. Bower,

    This is exactly the data I was looking for, but couldn’t find.Now if we can just get data on how effective the battery pack’s insulation is, we would know enough to draw firm conclusions as to when and under what conditions range will be seriously degraded.We do know, of course, that range is reduced significantly when operating below the freezing point, so the insulation can’t be perfect.

    Think MDI.

    http://gm-volt.com/forum/showthread.php?5328-Volt-Diagnostic-Tool

    We could write some pretty cool technical articles since we would have are the MG speeds and all the individual pack temps at our fingertips. I proposed a “group owned MDI” where we would split the cost of the unit and the subscription but so far it has not happened.


  37. 37
    Jackson

     

    Vote -1 Vote +1

    Jackson
     Says

     

    Aug 24th, 2011 (1:31 pm)

    Bill Destler,

    No disrespect or criticism intended, just curious:

    What happened to Jeff?


  38. 38
    Jackson

     

    Vote -1 Vote +1

    Jackson
     Says

     

    Aug 24th, 2011 (1:37 pm)

    George S. Bower: We could write some pretty cool technical articles

    Et tu, George? ;-)


  39. 39
    James

    +3

     

    Vote -1 Vote +1

    James
     Says

     

    Aug 24th, 2011 (1:40 pm)

    flmark,

    Hey Mark,

    I saw a write-up for a winter jacket in a magazine. It used micro thermal thread to spread heat throughout the coat – powered by small lithium batteries that attach/detach with velcro strips in the back area of the lining. I forget the brand-but they said the company does business with the military, where their tech is utilized, but with larger batteries. The jacket even has a jack in the pocket for your iPhone/iPod!!!

    It is nuts to have an article in August about winter EV performance, yet this is the time to start planning for Christmas when your business depends upon it. People with bright ideas can plan ahead-and hey, perhaps a line of “EV clothing” would sell big! One thing is for sure – with EVs ramping up slowly, anyone who starts planning now for such products will be WAY ahead of the game with patents, etc.

    If we place our EV clothing charger next to the place where we hang our charge cord, it would be handy to just insert the batt in a pouch or pocket located strategically on our jacket. The motorcycle industry already has vendors that sell heated clothing. One wonders ( James scratches goatee… ) just how large a market would be for threads that will allow one to preheat one’s cockpit less, only use defrost for several months of their year. I’m riffing here, but Nissan heats Leaf’s steering wheel, why not heated driving gloves?

    Anyway, it’s food for thought.

    PUMP OUT THE VOLTECS! ,

    James


  40. 40
    Loboc

     

    Vote -1 Vote +1

    Loboc
     Says

     

    Aug 24th, 2011 (1:53 pm)

    George S. Bower: What we need is a readout on battery temperature.
    The MDI would do that.

    http://gm-volt.com/forum/showthread.php?5328-Volt-Diagnostic-Tool

    http://www.boschdiagnostics.com/TESTEQUIPMENT/DIAGNOSTICS/SCANTOOLS/MDI/PAGES/MDI.ASPX

    It says it requires a GM tech subscription and doesn’t give pricing. Doesn’t anybody know a GM guy that has access to these kinds of tools?

    —-
    General Motors MDI
    Part Number: F-00K-108-322

    GM MDI (Multiple Diagnostic Interface) for wireless ECU reprogramming utilizing J2534. Hardware kit only.

    Note: Requires software subscription to GM SPS (Service Programming System), which must be purchased separately via the ACDelco Tech Connect website.

    Edit: The thing is $2400 bucks plus whatever the subscription is.

    Edit II:
    Option 1 – TIS All
    All GM Tech 2 diagnostic software and vehicle calibrations
    $1,395 per year

    Option 2 – TIS-SPS
    All GM vehicle calibrations
    $995 per year
    $275 for 3 months
    $55 for 2 days

    Option 3 – TIS-Tech 2 Updates
    All Tech 2 scan tool diagnostic software
    $750 per year

    Option 4 – GDS 2
    GM Global Diagnostic System PC-based software for some 2010 and newer GM vehicles
    $550 per year
    $225 for 1 month
    $55 for 3 days


  41. 41
    James

     

    Vote -1 Vote +1

    James
     Says

     

    Aug 24th, 2011 (2:15 pm)

    OK, I’m running with this:

    What about cooling EV clothing? Sharper Image sells that little fan that wraps around your neck – others sell those ice gel thingies that do the same. These things are easier for me to image in my mind since we’re having our “heat wave” the last couple days interspersed with Seattle’s ” La Nina/ El Nino ” weather cycles giving us a dismal summer at best ( we’re eyeing Florida ).

    Roof-mounted solar always appeal to techno junkies like us, although paying a premium for such hurts. Over at Priuschat, there’s threads on how effective their solar roof panels are and how to use them most efficiently. I think Toyota hits gadget guys head-on with it’s tech pkg.. You get lane-keep-assist, laser cruise and a solar roof – I believe even self park is available. From what I’ve observed so far – some of this *rap, or ( icing on the cake ) is useless. One lady I spoke to had just taken delivery of her 2010 Prius and was telling me the lane-keep was a real annoyance. Even with steering wheel control she said the way it operated was counter-intuitive and had to be switched on to make other features functional – always beeping even when she changed lanes.

    One wild idea I had was a seperate unit tied to a home solar array or wind turbine and battery storage that would be tied into your Volt while parked in a predetermined spot. This small system could start an accessory heater installed in the car yet not operated by the internal electrical system. The system could pre-condition your interior at set times or even with the flip of a switch or tick on your smartphone. The system could be especially small and not so expensive ( small thin film solar panel, small lithium battery ) – it’s sole purpose to heat the interior or cool it to 70-72 degrees. It would be interesting to see a cost/benefit analysis of such a device in extra EV miles added. Could the factory system be designed for owner designation of alternate shore power for just cabin conditioning?

    Why not just a very small squirrel cage fan and a flexible hose with a fitting at the rear of the Volt’s hatch for people with attached garages? This would be the redneck’s solution to pre-conditioning your car – just take the interior house temp and blow it into the car?

    Hmmmm….

    I have too much time on my hands today!

    RECHARGE! ,

    James


  42. 42
    George S. Bower

     

    Vote -1 Vote +1

    George S. Bower
     Says

     

    Aug 24th, 2011 (2:22 pm)

    Loboc,

    It’s been a while since I studied the thread but I think WOT said we should have a consumer oriented subscription available soon…..but I’d have to study it.

    I think WOT is keeping a list of guys that would be interested in being in the “group”.

    Group membership has qualifications TBD I think but the “I’m interested” thing is open to all.

    Anybody that’s interested send WOT a PM.

    He is “the man”.


  43. 43
    Jeff Cobb

     

    Vote -1 Vote +1

    Jeff Cobb
     Says

     

    Aug 24th, 2011 (2:26 pm)

    Jackson: Bill Destler,

    No disrespect or criticism intended, just curious:

    What happened to Jeff?

    What do you mean?


  44. 44
    Jackson

     

    Vote -1 Vote +1

    Jackson
     Says

     

    Aug 24th, 2011 (2:34 pm)

    Jeff Cobb: What do you mean?

    I guess I thought that Bill was subbing for you in every respect. My bad (I see where it says “posted by Jeff Cobb” at the top, now).


  45. 45
    Jeff Cobb

     

    Vote -1 Vote +1

    Jeff Cobb
     Says

     

    Aug 24th, 2011 (2:51 pm)

    Jackson,

    No worries.


  46. 46
    Jackson

    +1

     

    Vote -1 Vote +1

    Jackson
     Says

     

    Aug 24th, 2011 (2:54 pm)

    James: What about cooling EV clothing? Sharper Image sells that little fan that wraps around your neck – others sell those ice gel thingies that do the same. These things are easier for me to image in my mind since we’re having our “heat wave” the last couple days interspersed with Seattle’s ” La Nina/ El Nino ” weather cycles giving us a dismal summer at best ( we’re eyeing Florida ).

    The “Cool Suits” worn by NASCAR drivers could be a model for this; lots of little tubes circulate cool fluid near the body (underneath a thick protective coverall). Problem: they’re expensive (partly because they’re handmade, I expect). Also, any cooling thingie (without the insulated cover) needs a way to allow the wearer’s skin to “breathe;” so that means lots of small openings between the tubes. Would this make the garment more fragile?

    And finally (since I thought of refrigerated seats sometime back), you have to keep in mind the high humidity which the Southeast experiences: If cool enough to do any good, your wearer would quickly be drenched with condensate (my seat would have produced an even more embarrassing result ;-) ).

    Here’s a thought; come up with an air dryer based on a desiccant wheel or belt (recharged by waste heat from the engine, when it is on). Lowering the humidity makes even warm air feel cooler, as it magnifies the effects of perspiration (“but it’s a dry heat”).

    “This basic dehumidification process uses a special humidity-absorbing material called a desiccant, which is exposed to the air to be conditioned. The humidity-saturated material is then moved to a different location, where it is “recharged” to drive off the humidity, typically by heating it. The desiccant is usually mounted on a belt or other means of transporting it during a cycle of operation.”

    http://en.wikipedia.org/wiki/Dehumidifier (“Absorption/desiccant”)

    … you know, since we’re kind of throwing ‘out there’ ideas, well, out there.


  47. 47
    George S. Bower

     

    Vote -1 Vote +1

    George S. Bower
     Says

     

    Aug 24th, 2011 (2:58 pm)

    Loboc: http://www.boschdiagnostics.com/TESTEQUIPMENT/DIAGNOSTICS/SCANTOOLS/MDI/PAGES/MDI.ASPX

    It says it requires a GM tech subscription and doesn’t give pricing. Doesn’t anybody know a GM guy that has access to these kinds of tools?

    —-
    General Motors MDI
    Part Number: F-00K-108-322

    GM MDI (Multiple Diagnostic Interface) for wireless ECU reprogramming utilizing J2534. Hardware kit only.

    Note: Requires software subscription to GM SPS (Service Programming System), which must be purchased separately via the ACDelco Tech Connect website.

    Edit: The thing is $2400 bucks plus whatever the subscription is.

    Edit II:
    Option 1 – TIS All
    All GM Tech 2 diagnostic software and vehicle calibrations
    $1,395 per year

    Option 2 – TIS-SPS
    All GM vehicle calibrations
    $995 per year
    $275 for 3 months
    $55 for 2 days

    Option 3 – TIS-Tech 2 Updates
    All Tech 2 scan tool diagnostic software
    $750 per year

    Option 4 – GDS 2
    GM Global Diagnostic System PC-based software for some 2010 and newer GM vehicles
    $550 per year
    $225 for 1 month
    $55 for 3 days

    I think GDS-2 is what WOT was talking about doing.
    So if there were 10 guys in the group it’s almost affordable.
    139$ one time expense plus around 5$/mo for the subscription.


  48. 48
    Jackson

     

    Vote -1 Vote +1

    Jackson
     Says

     

    Aug 24th, 2011 (3:06 pm)

    James: One wild idea I had was a seperate unit tied to a home solar array or wind turbine and battery storage that would be tied into your Volt while parked in a predetermined spot. This small system could start an accessory heater installed in the car yet not operated by the internal electrical system.

    Hard to see how this would be any better than just charging the car with the current produced. The car would then parse the power out to precondition the cabin; without any extra gizmos to make your alternate-energy station power a separate electrical system. JMO.

    James: Why not just a very small squirrel cage fan

    … and a very small squirrel?

    j/k

    James: [ ... ] and a flexible hose with a fitting at the rear of the Volt’s hatch for people with attached garages? This would be the redneck’s solution to pre-conditioning your car – just take the interior house temp and blow it into the car?

    Hmmmm….

    This might work if the conditioned part of your house is very close to where the Volt sits in your garage; and if the hose is insulated.

    Maybe you could make a foam cutout the size and shape of a rear window when it is mostly open. Connect the hose though the foam, and roll up the rear window to keep the foam in place. Remember to ‘crack’ the opposite front window to allow air to exit.

    Be sure to use lots of duct tape.

    Then, take a picture to post here. Now that would be a hoot!


  49. 49
    George S. Bower

     

    Vote -1 Vote +1

    George S. Bower
     Says

     

    Aug 24th, 2011 (3:29 pm)

    James:
    This would be the redneck’s solution to pre-conditioning your car

    Hmmmm….

    I have too much time on my hands today!

    RECHARGE! ,

    James

    This might be good for someone that was “broke azz’ and living in a single wide .


  50. 50
    Jackson

    +1

     

    Vote -1 Vote +1

    Jackson
     Says

     

    Aug 24th, 2011 (3:54 pm)

  51. 51
    JohnK

     

    Vote -1 Vote +1

    JohnK
     Says

     

    Aug 24th, 2011 (4:01 pm)

    Loboc: Also, do you need to remove the charging cord to start the car (using the dash button, not the remote), or, does it allow you to start but you can’t engage ‘drive’ until the cord is unplugged. Is there some kind of visual or audio, or does it just not go into drive.

    If still plugged in you can “start” the car, but cannot put it into drive (and if you are still a little bit sleepy it will really confuse you).


  52. 52
    Loboc

    +2

     

    Vote -1 Vote +1

    Loboc
     Says

     

    Aug 24th, 2011 (4:09 pm)

    Jackson: take a picture to post here.

    I don’t have one for redneck heating, but, cooling… Got ya covered!

    CadillacGenerator.jpg


  53. 53
    George S. Bower

     

    Vote -1 Vote +1

    George S. Bower
     Says

     

    Aug 24th, 2011 (4:12 pm)

    Loboc: I don’t have one for redneck heating, but, cooling… Got ya covered!

    Good one Loboc!!
    Creative tail light too.
    This could catch on in Tonto Basin!!


  54. 54
    Jackson

     

    Vote -1 Vote +1

    Jackson
     Says

     

    Aug 24th, 2011 (4:25 pm)

    James: What about cooling EV clothing?

    Well, if all else fails, there’s always this:

    http://www.anti-strib.com/blog/save-the-planet-go-naked.html

    Not only cool, but “green” … and cheap as well!

    … still waiting for them to ban the fizz in soft drinks. It’s CO2, you know …


  55. 55
    Jackson

     

    Vote -1 Vote +1

    Jackson
     Says

     

    Aug 24th, 2011 (4:41 pm)

    James,

    “I’m not laughing at you, I’m laughing near you.”

    –Robin Williams


  56. 56
    IQ130

     

    Vote -1 Vote +1

    IQ130
     Says

     

    Aug 24th, 2011 (5:36 pm)

    OT

    Euro NCAP continues to test plug-in and electric vehicles and announces that the Opel/Vauxhall Ampera achieves an overall rating of 5 stars. The new range-extending EV reaches the maximum points in the side pole test as a result of a well optimized balance of structure, interior and restraint system.

    http://www.euroncap.com/results/opel_vauxhall/ampera/2011/443.aspx


  57. 57
    kdawg

     

    Vote -1 Vote +1

    kdawg
     Says

     

    Aug 24th, 2011 (7:16 pm)

    flmark,

    It could charge their cell phones in their pockets too. :)


  58. 58
    CorvetteGuy

     

    Vote -1 Vote +1

    CorvetteGuy
     Says

     

    Aug 24th, 2011 (8:13 pm)

    Jackson: Well, you never will guess what country has the worldwide lead in this area:

    Future clothing is the OT of the day?
    Hmmm….

    I would prefer the Nike shoes that tie themselves when you put your foot in them.
    Remember “Back to the Future: Part 2″ ?

    nike_future.jpg


  59. 59
    George S. Bower

     

    Vote -1 Vote +1

    George S. Bower
     Says

     

    Aug 24th, 2011 (8:26 pm)

    Bill,
    Thx again for the great article.

    You should consider the “group MDI”. I would be game even though I don’t have a Volt. Just reading you guy’s experimental results would be fascinating.

    A plot of battery pack temp as a function of time (hours) for various “cold soak temperatures” would be very interesting!!

    It might even be more interesting in the hot summer where the system does all sorts of interesting things.

    The Charles Whalen thread is esp interesting since he lives in Florida and it is very hot. He is a long time owner of a original Toyota Rav4 (and a current Volt owner I think) and he has some interesting tricks you can pull in very hot weather like we are having right now in PHx (115 degrees!).
    GSB

    PS Its the same thread that Chris C posted the table. go to the end and go backwards.


  60. 60
    Jackson

     

    Vote -1 Vote +1

    Jackson
     Says

     

    Aug 24th, 2011 (10:47 pm)

    CorvetteGuy: I would prefer the Nike shoes that tie themselves when you put your foot in them.
    Remember “Back to the Future: Part 2″

    This would be the more relevant gizmo from BTTF 2 …

    2qx1ano.jpg

    ” … your jacket is now dry!”


  61. 61
    James

     

    Vote -1 Vote +1

    James
     Says

     

    Aug 25th, 2011 (12:04 am)

    hahaha … the thread kind of went south, but what the heck!

    Sorry – but really – those shirts look GRRREAT!,……..don’t they?……….anybody?…….

    uh…………hello?………………don’t they………………………………..anybody?…………………………………………………………………………………………………………………………………………………………………………………………………………………………………………OK, I’m a geek!

    LOL,

    RECHARGE! ,

    James


  62. 62
    Chris C.

     

    Vote -1 Vote +1

    Chris C.
     Says

     

    Aug 25th, 2011 (12:08 am)

    I haven’t read the comments, will just jump in with this feedback.

    My Volt experience has been that A) in the hot Atlanta summer I consistently get about 35 miles of range, and B) in the cold winter I consistently GOT about 25 miles of range. Summer here is 95 and humid every day for 3-4 months straight, so the air conditioning is blasting. Winter here is 30-50 pretty reliably, with occasional excursions above and below that range. I drive with a lead foot.

    Back in December I put together a post in the GM-Volt forums that tried to document what we knew about the battery TMS temperature thresholds. If you’re interested in this, you really need to look at this table:

    http://gm-volt.com/forum/showthread.php?5243-Volt-thermal-management-system-temperature-band&p=48601#post48601

    It’s linked from my FAQ at:

    http://gm-volt.com/forum/showthread.php?5801-Frequently-Asked-Questions

    If anyone has specific information to add to that table (or that contradicts it) please post in that thread.


  63. 63
    James

     

    Vote -1 Vote +1

    James
     Says

     

    Aug 25th, 2011 (12:42 am)

    Jackson: The “Cool Suits” worn by NASCAR drivers could be a model for this; lots of little tubes circulate cool fluid near the body (underneath a thick protective coverall). Problem: they’re expensive (partly because they’re handmade, I expect). P>

    Here’s a link about how NASCAR drivers stay cool inside the heat of a racecar ( very interesting piece ). http://www.usatoday.com/sports/motor/nascar/2001-08-08-heat.htm

    It seems “cool suits” have gone by the wayside in favor of a more effective system where a small air conditioner pumps cool air into a tube entering the driver’s helmet – it says it cools mainly just the area around their mouth so that at least the air they’re breathing is cold ). $6k per unit and a Volt driver’d look pretty odd wearing a full-face helmet on the daily commute!

    RECHARGE! ,

    James