While camping without power hookups, it is important to closely monitor how much power you are drawing from your batteries and how much reserve power remains. I installed this TriMetric Battery Monitor in my RV to give me real time accurate measurements from my battery bank. In this video I'll walk you through the features and tell you all about it.
Bogart Engineering TriMetric Battery Monitor for RV (TM-2030-RV)
This is the latest version of the unit we installed in our RV. This unit measures your current state of charge in amp hours or percent full, charging/discharging amps (or watts), and current voltage level. It can also measure voltage level of a second battery. I use it to measure my chassis battery level as well.