I have just completed the install of my RV's solar electrical system.
I've got 6 used 6Volt Crown industrial batteries. Each is rated at 325AH. That should be a total of 975AH for the 12 volt system.
They are all charged up to 1.225 or higher SG and measure about 12.4 volts for each set.
However, when I turn on the lights and am running a 225 watt load, the voltage drops to 11.9 volts.
If I try to run a 1000 watt load, the voltage drops to 10.5 volts.
My guess is that the batteries are sulfated and can't supply much output.
Does this make sense? Or am I missing something?