Ghosts in the machine

Well, it’s been an expensive few days. The voltage regulator blew and zapped our house battery bank with >16V for about 30 minutes before I noticed something was amiss. When I topped them up, I had to add 3 liters of distilled water. That’s for two golf cart batteries. Yes, they are now dead. I guess it was time to replace them, they were eight years old, which is pretty good.

However, during my trials and tribulations, I checked what the current through the batteries is with the house battery switched on (and starter off), and the main circuit panel breaker switched off. This should have been zero, but it was 2 amps. (I use a clamp on ammeter). Two amps of ghost current, going who knows where is worrying. All that should have been connected is two bilge pump circuits (the switches have a small LED, and we use a WaterWitch which has a low current draw). I looked around and could find nothing that should have that kind of load.

Has anyone else made this measurement and found such a large current?

The wiring is mostly original, but the PO made a number of mods so there are lots of unidentified wires running around.

Just thinking for a moment, 3 liters of water is about 3000/18 = 166 moles. Each mole of hydrogen is 22 liters at STP, so that episode liberated about 3.6 cubic meters of hydrogen. I’m glad I don’t smoke. That’s scary. At least the engine is sucking out 100 cu ft per minute (about 2800 liters per minute) so I guess the engine would have sucked it out as it was formed and it probably never was dangerous.

Anyway, curious to know if other people have ghost power theives on board.

Van