Replacing the NiMh batteries for Li-On batteries in a pack?

[Notyu Oviosly]

I found this weird screen and battery add-on bundle for the gamecube on the web, but the battery pack is NiMH and lasts 1.3 hours long and takes around 8 hours to charge.

Is there any way to replace the internal batteries with Li-on ones? I know this thing must contain a big pack of these, but how could I go about replacing them with something a little more....mmmmmmm......useful?

[snowpenguin]

Well, you can. Get a li ion or lipo battery at the correct voltage that you know will fit in the old battery housing, and attach it in there, don't forget the protection circuit. Then, add a charge port on the outside accessible area of the battery pack.