Dead batteries with almost nothing on

[Jack_Hall]

I came home 150 miles with only the refrigerator on, and arrived home with dead batteries (2 each deep cycle 12V marine flooded batteries). At least I THINK the batteries are dead. The RV is a 24 foot Holiday Rambler pull behind trailer with added on solar panels (2 190 watt panels), and Bogart Engineering battery monitor and charge controller The interior house lights are dim, and the battery monitor has no lights. I have done NO testing yet- it is wet, dark and cold. In thinking about it, I came up with the following possibilities:
1) Bad diode in solar charge controller
2) Bad diode in either of my 2 solar panels.
3) Broken battery case, causing electrolyte loss.
4) Loose connection of a main power wire either plus or minus.
Has anyone else had this happen? If so, what was the problem in your case?

[okcnewbie]

I would check the voltage at the batteries. If dead, install a charged battery and then use your battery monitor to troubleshoot the charging situation. Does it charge via alternator, inverter/charger, solar, etc.

Do you have a generator? Does your big boy solenoid work?

[153stars]

Are you sure something else wasn't sapping juice , cycling water pump will drain some batts down. Did you unplug recently and expect them to be fully charged when you left? Is solar only charging while driving or are batts charged via trailer plug as well.? Depending on size of solar array , many good low cost MPPT charge controllers out there if it's dead. Price goes up quick after 30 amp size.
Most multimeters will series amp test to 10 amps through them.

[Old-Biscuit]

Do you have a battery disconnect switch?
Is it ON?

Tow vehicle.....does it have 7 pin connector with 'charge line' that is actually HOT?

Refrigerator ON.....
What type of fridge ?
All electric---an Electric/LP or a Electric/LP &DC
IF DC was it operating in DC Mode?