Battery Voltage - charging
MS44Houston - 2015
I am learning about my rig and how the battery charging system works. During this process, I am plugged into campground power.
First, Battery voltage is 13.7v
Next, I removed the red disconnect switch and 6 hrs later, the batteries discharged to 13.2v as expected.
Next, to get the voltage back to 13.7v with a solar panel. So, with red disconnect still removed, I connected a 18W solar panel to the batteries with a charge controller. 24 hours later, but the battery voltage was still 13.2v
So, to get the voltage back to 13.7v, I removed the solar panel, and replaced the red disconnect switch to ON. 24 hrs later while connected to shore power, the battery voltage is still 13.2v. 3 days later, still 13.2v.
Why is it not charging back to full charge?