identify / clarify difference between these batteries? Ask questions and find answers on all aspects of tools including hand & power tools.

[veletlen]

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Two B&D 18v NiCad batteries. They both fit my old 18v B&D EPC18 drill, but only the 2-pin/prong A18E battery works. The 3-pin ML:HPB18 is completely dead in the drill, but, after testing, seems to be fully charged. So, could anyone clarify the difference between these two batteries - at least in terms of what tool the useless-to-me 3-prong one is intended for, to that i can offer it to someone who could maybe use it...?

[veletlen]

... a little more googling and i'm inclining towards 'faulty' rather than 'incompatible', but still not clear what to do. The HPB18 is completely dead in the drill, but, after testing, seems to be fully charged (16.6V = OK for a not-new battery?). So, what kind of 'faulty' would fully-charged-but-not-working be?