My portable solar experience...
So, I bought a tri-fold, 150 watt solar panel and have been using it to charge my batteries. The trouble was the most I could get out of it was 13 volts. Calls to the company did not result in any good advice and was told that 13 volts was good. Reading the pamphlet for the charge controller told me otherwise. The charge controller is mounted on the back side of the panel. So, the wires going to the batteries were carrying the voltage needed to charge the batteries. With a 10 ga wire, it just wasn't enough charge to get the job done. I decided to remove the controller from the panels and rewire things so that the controller is right there at the batteries and the long cord is carrying the full voltage from the panels. Now, I am getting a full charge everyday. I plan to upgrade the wires to 8 ga and maybe get a better controller. My new golf cart batteries are getting better everyday. I have seen them fully recover from the water pump being used for several minutes.