I have tons of NiCd battery packs and tons of (sometimes) corresponding cordless drills. Only with a complicated discipline, involving several chargers, I can count on enough performance for a hard day's work. I did rejuvenate the individual cells by zapping; some packs improved, some packs died. The 'electric hubcap' site : http://members.shaw.ca/Craig-C/, states that a home made NiMH battery battery pack (several chains of 10 cells in parallel) can be charged and re-charged hundreds or thousands of times, and have a better performance than Lead-Acid... Is it worth the investment???