Robust electrical system issues

[TreeMoonGirl]

Hi-

Absolute newbie here and am learning by leaps and bounds every day I have my 1972 Airstream Overlander.

Solar system was installed last year and specs are:
-5 flexible solar panels at 100 watts each on the roof, -4X475 watt batteries with 1600 amp hours,
-4000 watt inverter,
-charge controller,
-battery monitor system

The trailer wasn’t being lived in while I got it set up and solar seemed fine-never used a lot of power, so didn’t notice any issues. Now that someone is staying in it and we had a cloudy day yesterday, the system seems to not be functioning properly. I connected it to shore power today and the batteries charged up hut as soon as I switched the shore power off, the battery level dropped to 80% and kept going down despite sun shining bright. What is happening? I’m worried the battery charged went below 50% and screwed them up.

Have a call into a solar specialist, but don’t want to do any (more?) damage.

Help!

[richard5933]

Give us more information about the batteries...brand, model, etc.

What ongoing/consistent loads are in the trailer?

Do you have a shunt-based battery monitor?

[LilPeanut]

Couple of quick things to check. There should be a disconnect switch next to your solar charge controller. It is intended to shut off power from solar so you can work on things without the solar power shocking you. Make sure it is turned on. If it is on, there is also a fuse on that line, make sure the fuse is good and the solar controller lights are lighting up as they should. If there are no lights, no power is being sent to the batteries from the panels.

Also, that is a pretty quick drop in state of charge. Did you have heavy loads going?