In a no gearbox serial electric transmission car, big high power torquey motors are needed for acceleration and hill climbing.
With good design these can have a very power to weight ratio,
infact better than ones in the Volt.

Note, In an IC car the gear box is allso a torque multiplier.

The Kw of the battery is not the limit on power output, but how many amps that can be pulled out of it, needs low internal resistance.

Example the 12volt starter battery in a car may only stores 750watts but the starter motor can deliver 5kw, the battery can do this for
0.75/5 hour i.e. not long.

Kw give you range not peak power. Range is limited by rolling resistance and overall wind drag. Lower these and the range goes up.

Weight just affects acceleration, very little else and on a good design 85% of the braking energy can be recovered and it makes little difference how hard you accelerate, the limit is wheel spin.

Same amount of power require (1/2mvSquared) no matter how quick you get up to cruise speed, infact an IC engine is best with throttle wide open as well. Less pumping losses.

Thats why the Volts is body is being reworked for a lower CD and may also come on special low rolling resistance tyres, as these are the things that will greatly affect the range.

The nice thing about the Volt is each system is seperate, motors, energy storage, on board power generation. Each can be optimised,
updated and changed to match which market it is being sold in.

Can’t do that on the Prius, to intergrated.

The Prius has always been a bit of a joke in Europe, as we have diesel cars that can do better, really just marketing by Toyota to look good and driven by the egocentric PC lot.

The Prius was the best that could be done 15 years ago and the concept is really past its sell by date. The Volt will be better but needs to be a little more radical, dump the inboard electric motors and mechanical brakes and go all electric, saves weight and space.

See this link and weep

http://www.pmlflightlink.com/archive/news_mini.html

This is what really can be achived with in wheel electric drive.
Makes the Volt look a bit old fashioned.

Spec 400 miles per charge, 900 miles using on board generator.
O to 60 mph 4.5 seconds, top 150 mph limited .

Volvo have a C30 in development based on this concept.

Thank You ThombDbhomb #101 for being the only reasonable relevent (to the post) comment on this thread. No offense intended for those reasonable non-relevent comments. Offense is intended to those dissing Lyle and his post.

This is HIS site dedicated to discussing the Volt, it’s development, and most importantly for prodding GM to produce the Volt. He does this in addition to being a doctor and family man. It’s ironic that Prius lovers would cast “bias” stones at Lyle from their own glass houses. The title of this post is a question, not a statement, and it is a very valid one at that.

Toyota’s official comments prior to the Volt were:
-they had no immediate plans to add plug-in capability and that the American public was not ready for plug-in vehicles.
-Li batteries were not ready for prime time

Now, this articles states that Li batteries and a plug are being considered. These changes may or may not have anything to do with the Volt, but posing the question is certainly valid based on prior history. Additionally Lyle gives due credit to the Prius in his comments. So, either the posters of detracting comments ingnored this or didn’t bother to read his post.

GM has acknowledged taking cues from Tesla and Toyota. Is it so unfathomable that Toyota is reacting to their competition? Large corporations take a lot of their direction from their competitiors, leading or lagging.

A higher energy battery and a plug is a good thing, regardless of where the impetus comes from. It’s telling, there weren’t many comments to this effect included with the stoning.

It strikes me as very likely that the induction motor could be entirely controlled and optimized by its own dedicated controller, which simplifies the central control algorithms.

Further, induction motors aren’t secret, either.

I spent a little more time thinking about the power electronics, motors and batteries this evening. I think the electronics are generally more sophisticated on these cars than we’ve been giving them credit for…

I know from the service manual that my Honda’s IMA system is 3 phase AC and there’s no 12V alternator, that system is powered by a DC-DC converter powered from the IMA. So, that’s probably one of the simplest hybrids and there’s quite a lot going on already.

I poked around and it appears the current version of the Prius actually uses a boost converter to up the voltage from the battery pack to the motor (this is a fairly technical article, folks):
http://www.techonline.com/product/underthehood/199501618
In a nutshell, they didn’t want to use enough batteries to make 500V, so they used a lot fewer of them to get 200V and just boosted the voltage using a converter. That makes the system more complicated than I’d imagined.

I was aware of some other electric car prototypes using ultracapacitors already… And after poking around I just noticed that the FCX Clarity no longer uses ultracaps. They switched to a Li-Ion battery, instead!
http://automobiles.honda.com/fcx-clarity/battery.aspx
That probably says a lot right there about the ability of these new lithium ion batteries to handle impulse power, although it also says a lot about the high power output of Honda’s new fuel cell, too.
(Private note to Honda: Didn’t you guys get the secret memo? You were just supposed to fiddle with fuel cells for 20 years, not actually make them viable in the short term!

Kind of makes me wonder what GM might be cooking up in the electronics for the Volt. When you start looking at it, there’s a lot of ways to set up the batteries and electronics. Heck, there’s a lot of ways to set up the converters, too…

Going back to the ultracapacitors for a moment, just off the top of my head I think if I were going to do a circuit with ultra capacitors I might try to use something like a buck converter to charge them on regen, and use the ultra caps themselves in a switched stacked capacitor arrangement for boosting the voltage for output and pass the power back out through another buck converter. The really fun thing would be to figure out how to flip the polarity of the buck after the capacitors are stacked using all the same circuitry for charge/discharge.
(for those following along at home, buck converters are very efficient and can dump huge quantities of current, but can only be used to reduce voltage, not increase it. Stacking the capacitors refers to an efficient but typically low power switching supply technique that can increase voltage by charging capacitors in parallel then switching them into series, much like what you would do when charging AA batteries individually in your charger then stuffing them in pairs in series into your mp3 player or electric toothbrush

Hmmm. I could use something like that on my solar system… (the power converter, not the toothbrush I might have to think about that some more.

What do you think GM is hiding from Toyota about the Volt? This is an engineering exercise. Once GM explains the basic layout, the only thing Toyota won’t know are GM’s (presumably) proprietary algorithms for powertrain control. And they’re likely simpler than the algorithms that manage the Prius. Motors, batteries, discharge rates, charge rates, controller efficiency… none of that is going to be particularly secret. Toyota will be comfortable with understanding all of that, as it’s about half – maybe two-thirds – of a Prius.

Jeff M, 112,

The Prius is a larger, faster, much safer, more comfortable, more reliable car. You could time the Metro 3-cylinder’s 0-60 times with a sun dial. The 3-cylinder was the high-mpg version. And the Prius does better in city driving, anyway.

You’re facile with the nonsense.

In 1976 the very epitome of a small fuel efficient car was the venerable VW Beetle. In 2009 the very definition of the worst gas guzzling SUV is the Cadillac Escalade.

How come I can order a model of the Biggest, Baddest, Gas Guzzler SUV, that gets 31% better mileage than the Bug, by not your fond recollections, but by the official record keeper, the CAFE custodians, the NHTSA.

They haven’t changed their measuring stick all these years so thy can compare a vehicles from different eras. The ‘76 Bug got 16 mpg. The 2009 Cadillac

escalade SUV gets 21 mpg.

The Caddy has to lug around a lot of stuff that the Bug never did. Airbags, front, side, rear, and curtain for example. Safety systems too. Bumpers, crumple zones, side impact beams. Did I mention disc brakes, traction control, ABS, Stabiltrack anti-skid and anti-rollover systems too.

On top of that the Caddy removes 999 times the pollution emissions that the old Bug emitted. That’s what the the EPA Lev II requirement is: 99.9% better than a non catalytic converter equipped car. Lots less NOx, SOx, CO, VOCs. So it takes a 1000 Escalades to emit more poison than ONE ‘76 Bug did.

Did I mention that the Caddy tunes itself automatically, hundreds of times a second, like every car, and even has a option for an automatic tire pressure gage to continuously check air pressure in the tires.

Both things the doofus, Our Savior, Obama-san, who doesn’t know his ass from a hole in the ground, urges that you do. Which will presumeably save the Country and World; and provide energy independence.

Yeah sure. We’ve stagnated all right… NOT!

It’s hard to realize how much slow steady progress adds up.

You don’t need to justify your decisions with me. I was not trying to be mean, just pointing out that we all make decisions based on our desires and needs (money comes in handy also)

I would love to own a BMW, Hummer, Prius, Volt, etc. Unfortunately for me the money part of the equation will trump most of my desires.