Originally Posted by jr_spyder
Thanks all. Had to get off the boat for a while to get warm and read more. I found some info in an obscure paragraph in the manual about needing to use an external charger if the batts get too low. So that advice above was correct - thanks. Will try that tomorrow and then search for the cause of the drainage, and disconnect the banks physically when I'm off the boat.
Most all "smart" chargers have a low voltage cut off. This keeps them smart. Charging
into a low voltage can mean the batteries have an internal fault or shorted cell. Charging into a fault can have the potential to blow the batteries up. This can be annoying but is really a good safety
When on he hard ALWAYS disconnect the neg or pos battery cable from the bank to prevent parasitic loads from killing the bank. I find disconnecting the neg side on many boats easier due to less terminals on the battery post.. Most boats have some level of parasitic load whether from a stereo, LPG sensor, battery monitors, combiners, Echo or Duo type chargers, solar
controllers or a myriad of other devices...
Also be sure to charge them to 100% capacity before leaving them. With the temps over the last month your batteries may recover but if they do will likely have a diminished capacity..
Get a dumb charger to bring the voltage up then let the Trace take over.