I have a Xantrex Prosine 2 inverter. It works great, and we have had it for several years without issue. I have started noticing, however, that the battery voltage on the panel of the inverter reads .4 volts higher (12.8 vs 12.4) than my cheap multimeter. I put the multimeter on other batteries and power sources, and it reads correctly.
I have a charge controller that reads the same voltage as the Xantrex panel.
So, I assume it is the multimeter, but the fact that it reads correctly on other things with a known voltage (vehicle batteries, etc), makes me think that maybe there is an issue with the inverter and/or charge controller connection.
Any thoughts?