Patent ID: 8823322

Claim:
A battery pack, comprising: a secondary cell battery; a current detection element for detecting a discharge current flowing from the secondary cell battery or a charge current flowing to the secondary cell battery; a monitoring section for inputting a current signal of the discharge current or the charge current through the current detection element and for inputting a voltage signal of the secondary cell battery; and a control microcomputer for performing discharge control or charge control based on the signals from the monitoring section, wherein: the current signal through the current detection element is input to both the monitoring section and the control microcomputer; and when a first difference between the discharge current signal transmitted from the monitoring section to the control microcomputer and the discharge current signal the control microcomputer acquires from the current detection element exceeds a first defined value, the control microcomputer stores a data showing abnormal discharge current is detected and outputs a signal for stopping discharging; or when a second difference between the charge current signal transmitted from the monitoring section to the control microcomputer and the charge current signal the control microcomputer acquires from the current detection element exceeds a second defined value, the control microcomputer stores a data showing abnormal charge current is detected and outputs a signal for stopping charging.