How to use a solar panel without frying a battery when it's done charging?

I am curious to know if i need a component that will stop my homemade solar panel USB charger to stop charging a device when the battery is full. could the solar panels over charge the battery when it's full? Will the unneeded voltage just turn into heat? I also would like to know if I can hook multiple devices that each use 5v and 500MA with a solar panel that puts out 5v and 8 amps without slowing the charging speed. Im sorry if I can't phrase the question right... please try to decipher my description of my problem

Re-design7 years ago
If you've got 8 amps coming out of the solar panel you have to be careful using it to charge any usb type battery. That is over 16 times what usb is rated at.
nepheron (author)  Re-design7 years ago
I would have a voltage regulator of 5v and .5amp. is it possible to fry a battery by over charging it with the solar panels?