What are the differences in Nickel-Cadmium (NiCd) and Nickel-Metal Hydride batteries (NiMH)?
A) "NiMH is a type of rechargeable battery similar to a NiCd battery but has a hydrogen-absorbing alloy for the anode instead of cadmium. Like in NiCd batteries, nickel is the cathode. A NiMH battery can have two to three times the capacity of an equivalent size NiCd and the memory effect (defined below) is not as significant.
NiMH batteries perform better with moderate drain devices such as digital cameras, flashlights, and other consumer electronics. Because, NiCd batteries have lower internal resistance, they still have the edge in very high current drain applications such as cordless power tools and RC cars.
Memory Effect - is an effect observed in some rechargeable batteries that causes them to hold less charge. NiCd batteries gradually lose their maximum energy capacity if they are repeatedly recharged after being only partially discharged. NiMH batteries will see very little memory effect. "