If it wrecks and the batteries short it's going to suck -- badly.

It is basically impossible to put an electrically-fed fire out unless you can cut off the energy. In the case of a battery fire until the energy in the battery is expended, forget about it -- it's going to burn.

Lithium cells are especially nasty in this regard because the heat from one of them burning will cause the separator (which is basically a plastic) in nearby cells to melt, which shorts THEM. This is a cascade-failure that will run until the entire pack is consumed, and since the pack is inherently buried in the vehicle you can forget about being able to draw enough heat away from it (e.g. with a firehose) to actually put it out.

Oh, don't get all excited over graphene batteries. Yes, IF they can make them work and IF they can manufacture them they promise materially higher energy density (good) and extremely-low (nearly zero) internal resistance, which means their charge acceptance rate is nearly infinite.

HOWEVER, this also means that IF one shorts internally it will not heat up -- it will electrically explode, since the available amperage will be very close to infinite. In other words the energy will all be released at once, which tends to result in what is sometimes called "rapid unplanned disassembly."

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