Today I noticed (according to the Xantrex battery monitor) that the batteries were being drained at a rate of -40A.
The Xantrex also said the batteries were at 37% of charge, and at -275Ah (for 4 Trojan T125s). Normal high draw rate is -10 to -15A.
These are new batteries, installed 2 weeks ago. They were charged to 75% yesterday. I shut off ALL power (refrigeration, bilge fuse, main breaker, battery switch) and still the drain was -40 A. I started the engine, which normally shows that +40 A is going into the batteries. Xantrex showed -8A, and battery percentage and Ah still dropping. That then changed to -40A with engine still running.
I turned off the engine, and the voltage was 13.0, the voltage draw was -74A!!!! And battery at 17% charge. And this is with everything turned off.
The battery ground to engine looks fine. The bilge pump fuse was pulled. Refrigeration turned off. Still -40A to -74A drain.
Any ideas of what to check next? Maybe the Xantrex is wrong? It has been flashing "Charge Battery Full" all of the time, full or not, since batteries were replaced.
Meantime I have disconnected the batteries to keep them from draining. But this is not ideal, as I am a live aboard.