Getting clost to being explosive...
As batteries get more "efficient", they approach being explosive devices. The problem is that the batteries are self contained energy devices, whereas common fuels (diesel, petrol/gasoline) need to be supplied with oxygen form the air to be useful.
Another way to have self contained energy sources, is to use hypergolic fuels (rockets use these). At least they are binary in nature and need both parts to generate heat.
This is the reason that batteries catch fire/explode all by themselves. Not fun.
Biting the hand that feeds IT
