Patent ID: 8674660
Filing Date: 2014-03-18
Classification: G01R,H01M,Y02E

Abstract:
1. An electric tool battery, comprising: a plurality of cells; a lead plate that is connected to electrodes of the cells; and a plurality of voltage monitoring elements capable of multiple monitoring of the voltages of the individual cells at the time of charging and discharging; wherein the lead plate has a plurality of voltage signal extraction portions respectively corresponding to the plurality of voltage monitoring elements, wherein the voltage signal extraction portions and the voltage monitoring elements are electrically connected to each other respectively via different conductors, wherein the plurality of voltage monitoring elements comprises a first monitoring element and a second voltage monitoring element electrically connected in parallel to the first voltage monitoring element and operable independently from the first voltage monitoring element; the first voltage monitoring element and the second voltage monitoring element respectively allow setting of an upper limit set voltage at the time of charging, such that when the voltage of the cells become higher than the upper limit set voltage, the first voltage monitoring element and/or the second voltage monitoring element output a voltage upper limit signal; and the upper limit set voltage of the second voltage monitoring element is set larger than the upper limit set voltage of the first voltage monitoring element.