Get a holder from radio shack for 4 cells or two cells and charge them really slow, like 0.1 amp, then discharge them at the same. You might have to do this a couple of times. Then hit them at an amp for one charge, and discharge at 0.1 amp. Then charge them up and see what happens. You might get them to be usable again. Basically all you are trying to do is give them a good deep cycle.