It would be rare to have all meter read the same. Wire length, wire gauge, connections, just the accuracy and quality of one meter to the next will give different readings. I know that when looking at voltage values in the C26 the Garmin, Volvo EVC, Blue Sea analog, and the Kisea inverter all had slightly different readings. The true battery bank reading would be best read directly at the source as Dan stated. You are not going to do this every time but a 1 time reading will give you an idea of which meter on board gives you the best true battery voltage. Knowing this gives you your answer. My method of reasoning of what my battery voltage was at anchor, averaging in my head. While on the hook I would generally have the Garmin on ( anchor alarm) my inverter on and the Blue sea analog is always providing a value. I never worried about battery voltage when the Meter readings were 12.5 or above. When I would see the Garmin reading 12.3 I would start averaging. Garmin 12.3, Kisea 12.0 and analog 12.5 I would consider it time to start the generator and start charging batteries. Myself, I think old school! Which meter is reading directly from the battery? The Garmin is not, the Kisea is not, EVC no, the solar panel is not. All the readings are from a processor in the unit. Accurate? Yes! The analog Blue Sea Meter is hard wired to the battery and the reading is direct from the battery. The Garmin, Kisea, EVC.... are using communication cables. I know!! Old school thinking ! So far it has worked for me. I'm the guy that could not quit using my Simpson 260 analog Multimeter. When the evolution of Fuel injection and advance electronic engine troubleshooting all testing procedures was done with digital. I broke down and purchased my first Fluke! I should not be posting this!!! I'm getting old!!
