Patent ID: 7394225

Claim:
A multiple cell battery charger comprising: a regulator for receiving an input voltage and supplying a regulated supply of DC voltage at its output; a plurality of charging circuits for charging a plurality of battery cells, each charging circuit configured to charge an individual battery cell, said plurality of charging circuits electrically coupled to said regulator and connected in parallel with respect to each other, each charging circuit comprising: a pair of terminals for coupling to a battery cell; a switching device serially coupled to said pair of battery terminals for selectively connecting and disconnecting said pair of terminals from said charging circuit, said pair of terminals and said serially coupled switching device forming a serially coupled charging circuit, wherein said plurality of charging circuits are coupled in parallel with each other; and a microprocessor operatively coupled to said pair of terminals for periodically monitoring the current applied to each pair or terminals of a battery cells and the time that such current is applied to said charging circuits and selectively controlling the switching devices so that the product of the electrical current applied to each battery cell and the time that such electrical current was applied to each battery cell is the same for all of said battery cells during a time period in order to charge all of said battery cells to the same charge level.