This would be a battery that turns on and off, pscn to turn on, nscn to turn off. This would be useful in some machines in order to store data, such as RAM and ROM in computers.
We already have switchable battery power. Take a CRAY, set its ctype to BTRY, its tmp and tmp2 to 1 and put a PSCN next to it. If you spark the PSCN the CRAY spawns a battery, if you spark it once more the battery is removed.