NiMH stands for nickel-metal hydride, which is one of the most successful batteries in history. It uses the same nickel-hydroxide positive electrode and KOH electrolyte as the Nickel-Cadmium battery but uses hydrogen gas to replace the cadmium in the negative electrode. The nickel-hydrogen battery is mostly used in low-orbit satellites, which charge and discharge the batteries on every pass around the earth, and requires a long cycle-life battery. Nickel-hydrogen cells have a cycle life of tens of thousands of cycles.
There are a number of charging methods that can be used with nickel-metal hydride batteries, although sometimes this isn't as straightforward as other types of cell or batteries. NiMH cells, similar to NiCds require charging with a constant current with the rate of charge typically specified on the case of the cell, with this rate not to be exceeded. Within the boundary of constant current charging, there are a number of techniques