Patent ID: 7560900
Filing Date: 2009-07-14
Classification: H01M,H02J,Y02E

Abstract:
1. A rechargeable lithium battery protection device for controlling an external circuit to charge or discharge a plurality of rechargeable lithium batteries, the protection device comprising: a plurality of diagnostic circuits, each of the diagnostic circuits electrically coupled to only one of the rechargeable lithium batteries, respectively, wherein each of the diagnostic circuits checks the voltage of the chargeable battery connected thereto and outputting a detect signal for checking the voltage of the single rechargeable lithium battery and outputting a detect signal; a plurality of light coupling circuits, each of the light coupling circuits electrically coupled to an associated diagnostic circuit for adjusting an impedance of the light coupling circuit according to the detect signal output from the associated diagnostic circuit for disconnecting the connection between the rechargeable lithium battery and the external circuit or charging or discharging the rechargeable lithium battery; and a plurality of resistors, each of the resistors parallel connected to an output port of one of the light coupling circuits, wherein the resistors have resistances different from each other; whereby the rechargeable lithium battery protection device can identify at least one abnormal rechargeable lithium battery by measure the overall resistance of the resistors at the output ports of the light coupling circuits.