Answer by
kevincai96 (669)
Not-all-batteries-are-created-equal, so-first-determine-its-type. Ask-your-local-hobby-store, or look for a label. Use this table:
NiCd = Nickel Cadium (Just-charge-and-discharge-completely-a-few-times,should-fix-it)
LiPo = Lithium Polymer (You're-screwed, go-buy-another-battery. Be-careful-too, they-are-explosive)
NiMh = Nickel Metal Hydride (See-Nickel-Cadium)