The Chevrolet Volt Battery Pack Fires 12/1/11 by Merkel F. Weiss
This past week, the National Highway Traffic Safety Administration (NHTSA) opened an investigation into battery fires in the Chevrolet Volt, one of the most important cars ever built by General Motors. The reason for this is that the Volt takes a fresh and technologically innovative approach to electric car design. The car is actually a type of electric/hybrid vehicle in which the electric motor runs the vehicle, powered by a battery pack of Lithium-ion batteries supplied by South Korea's LG Chem Ltd. When the battery pack has been sufficiently depleted, a gasoline engine turns on to run a generator and recharge the battery pack on board. The gasoline engine does not directly power the car, except through the battery pack. This makes it very difficult to assess an equivalent miles per gallon figure for the car, even though it does, at least to some indirect extent, run on gasoline. This car is intended to be the platform from which GM launches their assault on the coming Corporate Average Fuel Economy (CAFÉ) regulations which currently require some 54.5mpg by 2025. Using the strategy of electrification as in the Volt, I’d estimate that say, a Cadillac CTS-V Coupe performance car could achieve an equivalent 50mpg in the EPA city cycle.
The Volt was undergoing side impact testing at NHTSA in which it scored quite well. The wrecked car was then examined and stored. Some three weeks later, the car caught fire from within the battery pack. NHTSA engineers tried the test sequence three more times, and on two of these occasions the car caught fire again. Seeing a repeat of the condition that can only be called an internal defect in the battery pack, they issued a safety investigation notice.
General Motors immediate response was that the car was completely safe, but if anyone was not satisfied they’d buy the car back. Presumably, that goes for all three cars sold. I have not seen more than one Volt on the road here in Southern California at this date. I cannot believe that they are selling very well; after all it’s a compact $40,000 car of questionable, even experimental origins. Clearly, the Volt is the most recent GM innovation in a company known for innovation years ago, but of late has been falling farther and farther behind world standards in engineering and design. Example: most of the world’s prestige brands incorporate direct cylinder fuel injection to their engines in order to keep the cylinder to cylinder combustion as consistent as possible, thereby reducing the exhaust pollution generated and hence the exhaust pollution controls necessary to keep the engine within compliance. I have not seen any yet at GM.
You may have heard of or seen a Tesla Roadster on the street. It’s a battery powered car based on a Lotus Elise that has a mid-ship battery pack. As I understand it, the car is made by a Silicon Valley company familiar with computer construction, and so naturally, knowing that the battery pack can sometimes catch fire in a small computer, Tesla took steps to be confident that the batteries wouldn’t overheat. Essentially, they designed a cooling system that runs around and through the battery pack permitting the temperature control. Admittedly, the Tesla Roadster costs $100,000. A hefty price for a small car, but I submit that $40K is also a lot of money for the Volt. To my eye, it’s only a $25K car. The point here is that the design engineers at Tesla saw a problem and they designed a system to address that problem. This was not done properly in the case of the Volt. Apparently the battery pack coolant in the Volt leaked out and the coolant itself caught fire.
Listening to the feedback from Mary Barra, GM’s global product development chief, I see some notable quotes such as
“We are looking to say, 'Are there some design changes we can make, something even more robust in this location or that location or with this component, If we have to do something, we will. “
“There are a few avenues that we think could increase the robustness for this specific condition"
"We understand one of the very important premises of the Volt is the EV (driving) range and we plan to protect that,"
All this leads me to believe that there is still business as usual at GM. They learned very little from their bankruptcy and near death experience. True, America loves a winner and indeed is equally willing to forgive a loser who gets back on the right path. With this car GM has placed themselves on the path alright. This is the most innovative product that they have made since the days of the Chevrolet Corvair, Oldsmobile Toronado, Chevrolet Citation, Pontiac Fiero, and Saturn SL1. It’s a good product for GM, America, and for the industry in general. While this is a new car, it’s been GMs past history to put their design problems on the street and to let the public be their development engineers. Eventually the problems would be fixed alright, but after a time of evaluation, retest, and corrective action. Consider the difficulties in some the cars listed above, or if you prefer, how about the GM 5.7 liter Diesel engine, or the Cadillac V8-6-4?
It’s always been corporate arrogance that has caused GM market share to slowly erode from 48.3% in the 1960s to the current level of about 19.3%. Product design flaws were not even disclosed let alone addressed in a timely manner. I see much of that same corporate performance here and to those current GM customers who are not driving Oldsmobiles, Pontiacs, and Saturns for whom there is simply no hope whatsoever, I say to you: Good Luck.