Patent ID: 8548633

Claim:
A battery pack control circuit operable with interchangeable first or second battery packs, each having a different battery chemistry and first and second terminals for connecting to said control circuit, comprising: first and second drive circuits respectively coupled to first and second operative loads; first and second user-operable control switches in said battery pack control circuit for controlling operating modes of said first and second operative loads; a control processor coupled at outputs thereof to inputs of said first and second drive circuits and having first and second signal terminals respectively coupled-to and responsive to the operating state of said first and second switches, said control processor further having a sense terminal responsive to a terminal voltage of said interchangeable first and second battery packs; and a program operative in said control processor to select the level of a drive current to each of said first and second drive circuits responsive to said terminal voltage, said operating state of said first and second switches, and an operating state of said first and second operative loads.