Originally Posted by Rock 'N' Roll Outlaw
NiMH is Nickel Metal Hydride, the chemical composition of the battery itself. Others are NiCd (Nickel Cadmium), LiPo (Lithium Polymer), LifePo (Lithium Ferrite Polymer) among others.
Just to let you know, it's not Lithium Ferrite Polymer. The composition is LFP/LiFePO4 or Lithium Ferrite/Iron Phosphate. As of now, it's got the highest abuse tolerance of Lithium batteries while still having better/comparable life cycle/discharge & charge rates/nominal & max voltage/etc as the other Lithium batteries. These are most commonly used in DIY electric cars and such where high safety is priority.