It didn't work again. It was performing as if not plugged in. With battery connected the red yellow came on then went to red. Did this whether plugged into wall or not. Tried on two different batteries. As soon as the sun came up and getting small solar charge the charger works. This is the...
I didn't read the whole thread so forgive me if info is irrelevant. On my boat the start battery does nothing except start engine. The house batteries charged from solar power everything. I have a 9 amp DC to DC charger so I can charge start battery or any other battery from the house batteries...
1 solar panel on the roof would be more discreet than an extension cord. My compressor cooler is very efficient. You could probably get by with 100 amp battery and a hundred watt solar panel.
You need to balance them. You can't do it with the charger you have. What is the voltage of the batteries now. You should probably be testing them out now in case there is any issues with them.
Put a switch or breaker between solar panels and charge controller. Turn panels off before switching from one battery to the other then turn panels back on.