- #460 of 544
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Re: Volt battery testing [larsb]
by corvette
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Jun 13, 2009 (8:00 am)
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Replying to: larsb (Jun 10, 2009 8:46 am)
I will say this: It used to be that lithium ion laptop and cell phone batteries would degrade significantly within about 18 months after they were manufactured. Newer models seem to have a longer lifespan. My father has a 30 month old notebook that still holds 90% of its rated charge. Apple introduced a new notebook last week and claimed a five-year lifespan on the battery.
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- #461 of 544
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Should GM take note?
by pf_flyer HOST
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Jul 14, 2009 (4:21 pm)
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While it's not surprising that the lights in the Volt group have basically been switched off while GM reinvents itself (could resist the pun  ), I think it illustrates that the Volt, or any other EV with limited range and a high price tag for that matter, is NOT the answer for what ails the North American auto market.
The Volt seems to be an answer to a question that nobody is asking.
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- #462 of 544
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Re: Should GM take note? [pf_flyer]
by dmathews3
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Jul 15, 2009 (4:29 am)
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Replying to: pf_flyer (Jul 14, 2009 4:21 pm)
The more info I get the more I feel the Volt is not what I want. I want a car that not only gets great mpg around town but can also most importantly get it on a drive across the U.S. What I'm getting from the bits and pieces is that once the electric runs out and it switches to the gas engine that in order to make enough electric to run the car at freeway speeds it would have to run at max RPM's. If this turns out to be true than that engine isn't going to last very long. Is everyone else seeing this too?
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- #463 of 544
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Re: Should GM take note? [dmathews3]
by michael2003
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Jul 15, 2009 (6:00 am)
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Replying to: dmathews3 (Jul 15, 2009 4:29 am)
The only thing that would seem to make sense is for the generator to make sufficient electricity to power the car at highway speeds and still allow some energy to be put back into the battery at I would guess 1/2 speed.
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- #464 of 544
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Re: Should GM take note? [michael2003]
by dmathews3
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Jul 15, 2009 (10:29 am)
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Replying to: michael2003 (Jul 15, 2009 6:00 am)
In order to run at highway speeds this article said the gas engine would have to run at max in order to make enough electricity to power the car and none to recharge the battery. Now if that means running at max on most generators they are governed and always run at a certain RPM no matter what where as a couple I know of idle low and ramp up depending on how much juice is required and then they don't go over what the governed one do which is around 3600rpm's which wouldn't be bad. Whether it was a poorly written explanation or if it is the way I took it to be than that car won't last long and there will be a lot of people very unhappy with it. I'm hoping it is governed at a certain rpm no where near max engine speed so it will last a few hundred thousand miles.
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- #465 of 544
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Re: Should GM take note? [michael2003]
by gfr1
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Jul 15, 2009 (7:41 pm)
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Replying to: michael2003 (Jul 15, 2009 6:00 am)
It sounds like you may have not read where GM has changed their philosophy while designing the Volt. It was to let the battery deplete and then crank the ICE for power to recharge the batteries. But, some time ago, they decided to let the battery run down to min voltage and then crank up the engine for motive power only!. This, I guess, will give the driver the incentive/requirement to minimize the ICE use and maximize the EV batt. only mode. I suppose that would maximize the EPA values, for advertisement and corporate mileage. But, I guess if you then have to go up a grade (think about taking an interstate out of LA, northbound!), it will likely be a 25 mph ride, sounding like a gas powered lawnmower, for an hour, or so! Also, it was originally thought to be a 500 total mile vehicle (per tank). Then it was to be a 400 mile vehicle. Now, I guess it probably won't be a 300 mile vehicle. I think the only in-motion battery regen. will be braking regen, and maybe for cost reduction, that might not happen either. -- GFR
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- #466 of 544
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Re: Should GM take note? [gfr1]
by dmathews3
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Jul 16, 2009 (4:12 am)
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Replying to: gfr1 (Jul 15, 2009 7:41 pm)
In other words it is going to be like everyone is saying a joke just like their first electric car.
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- #467 of 544
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Link to Volt website
by michael2003
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Jul 16, 2009 (4:39 am)
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http://chevroletvoltage.com/
Here's another location to gain some insight on what's happening.
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- #468 of 544
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Re: Should GM take note? [gfr1]
by michael2003
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Jul 16, 2009 (5:27 am)
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Replying to: gfr1 (Jul 15, 2009 7:41 pm)
I understood that it only takes around 50 hp to maintain highway speed; i'm sure it's a little higher depending on the grade and speed. The engine being planned for the Volt seems to be capable of generating significantly more than 50 hp, meaning (to me anyway) that it should be quite capable of generating sufficient hp to maintain the vehicle at highway speed and still be able to trickle excess energy back to the battery, even at low rpm's.
I understand that GM doesn't want to recharge the battery to a significant degree, in order to increase the life-cycle of the batteries. On a long downgrade I would expect that it's possible that the engine would even be able to shut down for a period of time.
At higher rpm's the currently planned motor should be capable to generating sufficient energy to handle all reasonable travel conditions. It wouldn't make sense for GM to not follow this plan if they expect the vehicle to have no compromises and be useful as a single vehicle for a family.
I found the following link to give a better description of how the engine/battery should work once the battery reaches its depletion point.
http://gm-volt.com/2008/08/25/what-happens-in-the-chevy-volt-past-the-customer-d- epletion-point/
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- #469 of 544
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Re: Should GM take note? [michael2003]
by gfr1
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Jul 16, 2009 (7:55 pm)
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Replying to: michael2003 (Jul 16, 2009 5:27 am)
You may have missed the point. My comment about the changes in regen. philosophy makes your article reference obsolete, because they've decided they want a electric vehicle and only want the ICE to get the vehicle home, if necessary, so to speak. No ICE regen. is planned, as of a couple of months ago. This came from an article (might be Popular Science, I don't recall) from the magazine's engineering editor while visiting the GM research facility. It's not what the can do, but what they've decided is the best course for their objectives, whatever they may be. It has nothing to do with the typical battery operating range of 30 to 80% thing. In this case, unless they change their minds again, when the battery gets down to 30%, as an EV, the electrical propulsion is off-line until recharged from a station. Anything can still change, but your reference has been superceded, as it stands now. -- GFR
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