this might be useful to everyone on a budget with an H camera. Here's my attempt to replace the dead battery in one of the grips that came with my H2.
All you need is (not enough money for a new grip ) the battery housing, a battery cage that takes AA batteries and some Li-Ion batteries that have proper dimensions such as these:
4 x 3.7V 1200mAh 14500 AA R6 Mignon Lithium Li-ion Regenerierbar Batterie Akku | eBay
Battery cage: Batteriehalter kompakt, 2x Mignon AA mit Anschlusskabel | eBay - Increadible how cheap both things are...
I think these images are pretty self-explanatory. Open the housing. Remove the battery but make sure to cut one wire at a time to avoid short circuiting the battery. Even if it's dead, there might still be some charge left. Connect the battery cage properly and and add two 3,7V Li-Ion batteries. Reinsert everything into the housing and seal it with the black piece of plastic. Before doing all this I checked the polarity with a volt meter. The positive terminal is the one that is close to the charger attachment (just connect red with red and black with black.. ).
I'm sorry for the bad quality of the photos, I only had my cellphone at hand.
The new battery grip works flawlessly. Like the specs of the batteries above suggest, it doesn't last as long as the original grip but nevertheless I get about 500 exposures out of it. It charges with the original charger and is lighter than the original grip.
I suggest using this resurrected grip with an H1, H2 or H4X camera. It will also work with the H3D, H4D etc. but since these cameras have DBs without power supply the battery will be drained even faster. So I doubt it'll be worth the hassle.