Low Voltage

Thanks Wolfe10. But sealed batteries. I'll charge until morning, let it sit a couple of hours and check voltage. Should I disconnect after charging?

I was thinking maybe like the LED lights I put in the outside fixtures that have exposed circuit boards. But they are not on.
Good thought though.

mabell wrote:
Here is what I did.
I left the charger off. Had all the lights on for a while.
Went back out and had 11.9 at the battery. OK.

OK, let's start with the root problem.

11.9 is a COMPLETELY discharged 12 VDC battery. 12.2 is 50% discharged.

Start by fully charging the battery(s).

If wet cell, after charging, check SG (Specific Gravity). You can find them for under $10.

Look for a 12v lamp that is wet, like maybe in the shower or outside.

Here is what I did.
I left the charger off. Had all the lights on for a while.
Went back out and had 11.9 at the battery. OK.
Pulled fuses at the panel for different lighting areas and verified 11.9 volts at the fuse base. But, at each bulb base, it was lower. Like the main lighting (10 bulbs) the light base socket showed 10.2 volts. Other areas with less lights showed slightly more, like 11.2 but still less than battery voltage.
So I flipped the charger back on and all the lights brightened, as you would expect. Batteries showed 14.2 volts, as did the fuse bases. The light socket bases showed more voltage than before, but not a full 14.2. More like 12.9 on the main lighting bank.
Is this normal. Less voltage because of the draw?
Will see if batteries come up to a full charge and hold that charge.
They are sealed batteries so I assume they can't be checked. Two group 24 batteries
I should add the trailer and batteries are 3 years old.
Thanks in advance.

You have resistance between the batteries and the loads.

It could be a loose connection, corroded connection, too small a wire gauge to lights, etc. You need to find out where the voltage drop occurs between battery and lights.

Be aware that 12.4 suggests that you are NOT on shore power with the converter or inverter/charger keeping the batteries charged. If you are plugged in with these readings, we need to dig deeper-- starting with what kind/number of batteries you have.