In reply to The Potato:
i'm not a camera expert by any means but electronics are my bag. i'm guessing this camera didn't used to drain the battery but the problem had recently manifested itself? if so there is a battery drain while it's switched off and this is most likely caused by a short to ground on the circuit board, water damage perhaps shorting a pos to a neg or a leaking capacitor (leaking a pos feed to ground)
These days schematics for these devices are impossible to find or simply are not available and repair costs are financially unviable.
just switch off by removing battery until such time you get a new camera.
