This circuit current limits to 2.1 A for charging my 3400 MAH battery at .6 C. If you have a larger or smaller pack you can adjust the resistors for different current limits. If you build this be careful of your resistor power dissipation, I'm using SMD 2w thick film resistors just because I had them laying around. They are a little expensive so if you wanted you could parallel a few resistors to get the power dissipation you need. Also if you want to be able to play and charge at the same time with the official gamecube power supply you might need to reduce the current limit to not over current the power supply.
