Regarding my questions above, I need the battery power for cloudy days (drats). I want to use solar as much as possible, but cannot avoid the need for batteries. I have been experimenting using any salvage battery I can find, but I bought some new 2500 ma Ni-mh batteries and want to do a respectable job of caring and feeding them. If overcharging defined as pumping in more amps than needed or using too high a voltage or both? Wish I knew this subject better, but I am listening, reading and trying. Thank you for your time.