Patent ID: 7646169
Filing Date: 2010-01-12
Classification: H02J

Abstract:
1. A method for protecting a battery pack from a current overdrawn condition, comprising the steps of: a) turning a discharge switch off when a large current overdrawn condition occurs; b) generating a control signal at a switch control circuit formed by a charge PET connected back-to-back to a discharge PET, the charge PET being connected by a charge driver and the discharge PET being connected by a discharge driver, the control signal having a predefined maximum level; c) generating a trickle discharge current under control of the control signal, the trickle discharge current having a threshold current level and being capable of preventing the large current overdrawn from the battery pack; d) detecting whether the large current overdrawn condition still exists according to the trickle discharge current, the threshold current level and the predefined maximum level; e) repeating the steps of a) to d) if the large current overdrawn condition still exists; and f) turning on the discharge switch if the large current overdrawn condition is removed.