Warrants watching. Mine never goes below 13.2 when on shore power, and up to 13.8 or 9 when its charging. The engine alternator runs the voltage as high as 14.2 or 3 when on the road, and charging, down to low 13's when charged. I only see mine under 13 volts when its not on shore power or being charged by the engine alternator.
__________________
|