A nickel metal hydride battery, abbreviated NiMH or Ni–MH, is a type of rechargeable battery. The chemical reaction at the positive electrode is similar to that of the nickel–cadmium cell (NiCd), with both using nickel oxide hydroxide (NiOOH). However, the negative electrodes use a hydrogen-absorbing alloy instead of cadmium. A NiMH battery can have two to three times the capacity of an equivalent size NiCd, and its energy density can approach that of a lithium-ion battery.
Pros
- Longer lifespan than LiPos, usually into the 1,000 cycles range
- Much less sensitive, and doesn't usually pose a fire risk
- Simpler chargers and
- routines required for use.
Cons
- Much heavier, and limited on size.
- Lower average capacity, and less efficient overall.
- Lower discharge rates; they lack tremendous punch.
