[RedDevil]

Oh, I dig that design.
Moving the magnet in a straight coil works fine for the milliWatts a flashlight needs, but we want several thousand times as much from the shock, while it usually travels far less than the flashlight magnet does.

This new design will spin up a rotating coil.
It has double merit; this way it converts the extreme high pressure but low travel of the shock to a fast moving coil, which will keep spinning once the shock stops. Instead of a sharp peak of several hundreds of kW that the batteries can't handle it gets smeared out over a longer period; the coils will not deliver more energy than the system can take, and just spin a bit longer then.