The media and the anti EV crowd have been getting quite worked up lately about the Chevy Volt battery pack and perceived yet unrealized dangers from fire. Two Chevy Volts were parked in garages that happened to burn down, just as happens to many ICE vehicles every year, yet in the Volt cases blame was automatically placed on the hybrid vehicles, presumably because they are something new. However in both cases the Volts and their batteries were found not to be the source of fires.
Then in May NHTSA ran a side impact test on a Chevy Volt. This test consists of sliding a vehicle sideways into a solidly mounted pole which totals the vehicle. The Volt passed the test for occupant safety.
Three weeks after the test, which damaged the battery pack, the pack caught fire. (Interestingly when the same test is done on conventional ICE vehicles the tank is drained, probably because NHTSA doesn't want gasoline flying all over it's facilities.) This seemed to be an isolated incident as other tests done by other organizations did not result in any fires. To further investigate NHTSA ran more tests on Volt battery packs, bare packs not in a vehicle. The packs were penetrated, further than in the original crash test, then rotated to simulate a rollover. In the first test nothing happened. In a second test there was a temporary temperature increase initially, then a week later this pack caught fire. In a third test the pack smoked and sparked but did not catch fire. At this point it seems that leaking coolant for the batteries can cause some short circuiting if the pack is not drained after a severe accident. There have been no fires in actual use during a crash of the Volt, and NHTSA considers the Volt to be a safe car which has a 5 star crash rating. GM is working on some upgrades which will further protect the pack and address this battery issue which would only happen in extremely rare circumstances.
There are over 200,000 vehicle fires a year in the US, all of them ICE vehicles, yet because the Volt is a new product people are trying to paint it as more dangerous than it really is. Any vehicle has risks, any energy storage container, be it battery or fuel tank, has the potential for mayhem, and nothing can be made completely safe. However, in the real world, the Volt has proven to be safer than most other vehicles on the road, and with the planned upgrades it should be safer still. I'd be much more concerned with the Volt's gas tank in a crash than it's battery pack. The LEAF, an EV with a larger, but air cooled battery pack, has had no issues in any crash test or real world accidents. Nor have any of the crashed Tesla Roadsters, with even larger yet liquid cooled packs. At this point EV's are proving to be statistically safer than ICE vehicles, as I would expect, and that trend is likely to continue.
Coolant cause of shorts