Ok so I looked trough the board again (but non specificaly on tank circuits), and I bumped onto this :
12-24V adjustable 5A regulator
This seems to be able to solve my problem am I correct?
If it is I guess I'd have to go fetch one of those things at a local electronics shop they should be able to get something like that easily no? Does someone know of a manufacturer of those types of devices in Europe?
However same question will this drain any battery while in standby mode on carpc?