I've some links about that, but can't post here

 

I've tried several times but can't find what's the error to post it here ?!?

 

I am doing some research on the methods used by Electric Vehicle manufacturers to minimize the possibility of electrocution of emergency workers and occupants of cars involved in a serious collision.
Most seem to use normally open relays, to switch the high voltage lines, probably activated by an accelerometer, and all powered by a 12V battery.
Is this the only method currently used. ?