My setup is a few years old now and it was working flawlessly till I let the rig sit a while last year. Now the BVM712 is constantly showing dropping SOC, no matter what charger is being used and even when the Victron IP67 is showing full battery, the BVM showing negative current yet the SOC on the BVM712 is dropping. My Renogy MPPT controller shows correct SOC…not sure what the deal is. Any ideas?
Your Renogy can't show correct SoC. It's voltage based and is garbage unless the system has been completely dormant for 10+ hours (no charging or discharging at all).
Is the ONLY thing attached to your battery (-) the shunt? If you have attached a charger directly to the battery terminal, the shunt can't see the incoming current, and it will only see the outgoing current.
It is critically important that all loads and chargers be attached where I have labeled "everything attached here"
Is your system wired like this?
