Almost every hand held electronic item we all use (game systems included) have 12-volt charger. Most things run from 6-volts and the car chargers step the 12-volts down to the 6-volts needed to charge and run the game or electronic item.

I have a palm pilot and it runs on 5.2 volts, this is close enough to 6-volts. I made a 4-d battery pack that will charge and run my palm pilot for over a month of use, it just happens it’s the same voltage and plug type to charge my cell phone, so I get double use out of it.

Doing something like this can keep your kids games up and running for a long time. Add a solar charger for D-Batteries and you have power indefinitely. You do have to part out a car charger to make one of these, and lots of people seem unwilling to chop up a $20.00 item, but it never bothered me to do it if it gives me something I want or need.