Originally Posted by
Ridefreemc
I had an odd experience charging (trying to) my phone with a 5 watt solar panel. It was overcast and the phone actually discharged. I heard that could happen overnight, but not on a fairly bright, but cloudy day.
Solar panels for marine use (which is mostly for trickle charging the marine batteries) HAD that problem in the past (discharging at night). Most of them now are wired with a simple diode that prevents current flow the discharging way.
You may wish to look for these.