Patent ID: 7944181
Filing Date: 2011-05-17
Classification: B25F,G01R,H01M,H02H,H02J,Y02E

Abstract:
1. A lithium-ion battery pack configured to be interfaced with a handheld power tool, the battery pack comprising: a battery pack housing; a plurality of terminals configured to be interfaced with corresponding terminals of the power tool; a plurality of rechargeable lithium-ion battery cells arranged within and supported by the housing, each of the battery cells having a respective state of charge, the battery pack having a state of charge, power being transferable between the battery cells and the power tool; a control circuit mounted on a flexible printed circuit board positioned within the housing, the control circuit operable to control a plurality of functions of the battery pack including discharging functions, the control circuit including a controller, the control circuit configured to control at least one function of the battery pack based on a monitored state of charge; and a switch configured, when open, to disable transfer of power between the battery cells and the power tool, the switch further configured, when closed, to enable transfer of power between the battery cells and the power tool, the switch including at least one field effect transistor (FET).