Hi I am an electronics dummy, but I still like doing my own work, so here's my problem. I have a solar charger (output 5.5 volts @ 500 ma). It has self contained batteries. When I connect it to my phone or usb battery charger it will charge for a minute (give or take) then shut off. My guess is that it thinks the batteries are fully charged, since depending on how low the batteries are it will go longer b4 it shuts off. What can I do to fix this? Can I fix it with some kind of inline fix?