HTC Fuze, Touch Pro OEM Extended Battery - 35H00117-04M: This Battery is an original advanced Lithium-Ion (Li-Ion) battery that is super light-weight, highly efficient cell composition with zero "Memory Effect". Lithium Ion batteries are a rechargeable power source that provide greater charge per pound than nickel metal hydride and do not require full discharges to keep the battery healthy. OEM Original Lithium Ion batteries are better with frequent, shallow discharges before charging again and unlike NiCd batteries or NiMH batteries, lithium Ion batteries should be charged early and often. Lithium batteries should not be stored in extreme heat.