Interesting, I have been logging voltage and temps while commuting. My voltage right after startup drops to 11.8 then after 5 seconds or so settles down on 14.1. Once warmed up she sits pretty steady at 13.9 regardless of load (all lights one and AC or no lights and HVAC off). Seems like 12.8 is a little low, what is the voltage of the battery with engine off? Hopefully others with more experience will chime in.