I guess you do not have a battery monitor
which shows used ampere hours. Since if you have a battery monitor
, the negative terminal of the battery may only be connected to the shunt, and all loads and chargers should be connected to the other terminal of the shunt.
If I remember correctly, in the non-evolution Mahé, one of the big M8 screws on the starboard side of the battery box
is the negative/ground connection. But I sold our mahé more than 2 years ago.
Just keep on checking, every hours spent investigating is useful in the long run. Better than watching TV.