MIT’s Technology Review puts forward the question: If one battery exploding in a laptop can cause so much damage, what sort of destruction can be caused if the 6831 batteries in the Tesla Roadster explode due to overheating or being in an accident? It’s a legitimate question, and one that Tesla CEO Martin Eberhard does well to answer.
Apparently there are a number of safeguards for this. Firstly, the batteries are used in blades, with each having a separate point of failure. This means one electrical problem won’t cause all the batteries to malfunction.
According to the article:
They have also included overcharging protection, three layers of fuses, and sensors that will trigger the batteries to disconnect in the case of high-temperatures, a sudden impact, or a roll-over. In fact, the decision to use many small batteries rather than a few very large ones was in part a safety consideration -- each battery and its relatively small amount of stored energy compared with the entire system is isolated and protected within its own steel case. And the entire system is also encased for protection in the case of an accident.
Read the whole article here.
Edit: Also note the hilarious conspiracy theories in the comments that this article was sponsored by the oil/car companies. Our take? It's a legitimate concern and we're glad to see Tesla have thought about it before putting the Roadster to market.