Hi there. I have been running my 75/15 in my car for over 12months, I have a 250w 36v PV on the roof, and up until last week, it run perfectly, keeping my crank and AUX batteries fully charged. My monitoring system alerted me to the fact my battery (AUX) was almost flat, so I checked out the system and found the PV input was only reading 13v, it should be reading 36v or so. Further investigation just now, shows 36v at the panel, 36v at the cables into the 75/15 when they are unplugged, when they re connected however, it only reads the 13v which I assume to be battery voltage. I am 99.9% sure this PV input reading is always 36v-40v when its daylight, irrespective of that, my batteries went flat.
Anyone offer some advice on what could be wrong here? Should I factory reset my 75/15 or is there another option or something I am missing.