We recently upgraded our two house banks on our sailboat to Lithium. All standard install processes were followed and a pair of 18V DC-DC chargers were added to replace the ACR's attached to the two engine batteries and associated alternators. The boat's generator is also attached to one of the start batteries as it is used to provide starting power for the device. We already had 2400W of solar onboard and the only changes made to that element and our inverter/charger were to reflect that the batteries were no longer AGM but Lithium (software changes). Final aspect of our configuration is that all of the solar controllers, DC-DC chargers, and shunts monitoring our system are Victron products. The inverter/charger is not Victron but was originally installed with the AGM setup and worked fine.
The issue/weird challenge we are seeing on the two BVM-712's monitoring the banks is that I would expect a draw (in amps), either individually or combined (they are connected to a switch allowing to combine or use independently) as a negative number when DC power demands are placed upon them. Conversely, I should see a positive number on the monitors when energy is being placed into them from solar, DC-DC, or generator power supplying voltage to the charger. Unless demand is higher than what is being put back in and I am not. I am seeing the opposite. We even ran a few tests by turning off all DC power draw sources and still had a negative draw being displayed on both 712's. I am seriously confused. Nothing was changed in our setup with the exception of the actual batteries, the addition of the DC-DC chargers, and the appropriate new gauged wiring, CB's, etc. for the new battery system configuration.
