Kevin Means
Site Team
I'm curious... what kind of RV do you have, and why do you want to power your 120 volt AC appliances differently than the way it came from the factory?
You said your batteries started indicating 12.2 volts five minutes after you connected your charge controller to the batteries. That 12.2 volts is NOT an indication of the battery-bank's voltage, it's an indication of the charge controller's output voltage, which isn't very much voltage for charging. (Maybe a cloudy day?)
You can't use a volt meter to accurately determine the SOC of a battery-bank when a charger of any kind is charging your batteries. The readings you get will be an indication of the charger's voltage - not the battery-bank's voltage. If you want to accurately measure the battery-bank's voltage, disconnect the charger and all loads from the battery-bank, let the batteries sit for about 30 minutes, and then hook a volt meter up to the batteries. That will give you a pretty good indication of the battery-bank's voltage.
If you want to know your battery-bank's SOC while it's charging, or discharging, you need a battery monitor (like a Trimetric RV 2030.) They're installed with a shunt and programmed for your battery-bank's AH rating. In my opinion, if your goal is to boondock, a good battery monitor is a necessity.
Kev
You said your batteries started indicating 12.2 volts five minutes after you connected your charge controller to the batteries. That 12.2 volts is NOT an indication of the battery-bank's voltage, it's an indication of the charge controller's output voltage, which isn't very much voltage for charging. (Maybe a cloudy day?)
You can't use a volt meter to accurately determine the SOC of a battery-bank when a charger of any kind is charging your batteries. The readings you get will be an indication of the charger's voltage - not the battery-bank's voltage. If you want to accurately measure the battery-bank's voltage, disconnect the charger and all loads from the battery-bank, let the batteries sit for about 30 minutes, and then hook a volt meter up to the batteries. That will give you a pretty good indication of the battery-bank's voltage.
If you want to know your battery-bank's SOC while it's charging, or discharging, you need a battery monitor (like a Trimetric RV 2030.) They're installed with a shunt and programmed for your battery-bank's AH rating. In my opinion, if your goal is to boondock, a good battery monitor is a necessity.
Kev