Monday, December 5, 2011

Chevy's problems go from bad to worse with the Volt

Regular readers of my blog will no I'm no big fan of the Chevy Volt, right from the beginning when Chevy kept insisting it was an electric vehicle when it is, in fact, a Hybrid with very little difference (electro-mechanically speaking) from the Toyota Prius. They lied about the whole electric vehicle thing and now I wonder if they bit off more than they could chew. Toyota have been producing the Prius for ages and there are no worries about battery pack fires or leaks. The design is nearly a decade old now. Yet Chevy's all-new Volt has apparently got some design flaw in the battery pack that can allow it to catch fire after an impact. This hasn't happened just once - it's happened several times now and Chevy are so worried about it that two weeks ago they offered to provide free loaner vehicles to owners worried about the battery fire problem. Now they've stepped that up a notch and are offering to flat out buy back the cars from their owners.
So why the sudden change? Why would a company the size of Chevy, not famous for it's customer care, now be offering to buy back cars from owners? My guess - C.Y.A. I think they've discovered some sort of critical design flaw that they know is going to embroil them in a huge lawsuit and they're trying to limit the damage ahead of time by offering the buyback scheme.
Let's face it, GM doesn't have the best reputation with electric or hybrid vehicles, dating back to the whole EV1 fiasco where they forcibly cancelled leases, and literally stole the cars back from their owners to destroy them. If you're interested in that whole nauseating mess, Who Killed The Electric Car is a great documentary on that very topic.


Vlad said...

Hi Chris,

I've just watched the documentary "Who killed the Electric Car". Very enlightening! The conclusion as I understood it, it's that they had a viable solution which they then chose to discard because of the long term implications (they wouldn't have get as much profit as they were by selling petrol engine cars).
So I think the EV1 wasn't a fiasco in terms of design?
Also I must credit their "genial" (note the ironical tone here) idea of steering the attention towards the hydrogen fueled cars (which were many times more expensive to produce and required at least 25-30 to reach a point where they could be mass produced).
I hope for a better future!


Paul said...

From what I have read the Volt :took part" in crash tests and three of them caught fire after side impact testing. The interesting part is that one caught fire 7 days(!) later, another 3 weeks later!.
Two articles...
Note the date, February this year.

Chris said...

Paul - correct. Which means something got split or broken and was working its way towards a fire for quite some time. Now obviously this is always a possibility when you have that much voltage, that much current and a huge trough of acid in the middle of the car. Heck - people's cellphone batteries catch fire. But to have it happen in this manner, twice, to the same design of car implies a design problem either with the safety structure of the car, or the design of the battery itself.

Justin said...

Hi Chris, I've been reading your blog for a while but this is my first time commenting on it. As a mechanical engineer that has worked on some hybrid electric vehicle projects, I just wanted to clarify a few things. The Volt uses Lithium Ion batteries, the same type used in laptops (remember the Dell fires) and cell phones. This type of battery is more prone to catching on fire when physically damaged than other types of batteries due to the very reactive nature of Lithium. They are not like normal car batteries and there is no acid inside. The Prius uses Nickel-metal Hydride batteries which are much more stable and less fire-prone than Li-Ion but heavier and have lower energy density.

The fact that so far the Volt cars involved in crashes did not immediately start on fire is a good thing, and a testament to solid structural design. The Volt batteries starting on fire some time after the crash is more of an issue of how to properly deal with and dispose of damaged batteries at wrecking yards. The batteries need to be discharged in some manner to reduce their possibility of fire. It would be nice if this feature was built in to the car, which is probably what GM is going to have to do.

Chris said...

That's interesting. Thinking back it's obvious the batteries aren't lead-acid - the damn thing would never move if it had that much weight in it :)
It's also key, I suppose, to why crashed Prius' seem to fare better in the battery department than the Volt. As you say, Li-Ion is more volatile than NiMh. I wonder if this will ultimately lead to GM having to go with NiMh instead and sacrificing the energy density for "safety" ?

Paul said...

In one of the articles I posted it mentions that, within 48 hours of being notified that a Volt has been in a crash, a team from GM is dispatched to drain the battery. The notification is via Chris's favorite mirror... On-Star :-)