| 摘要 |
PROBLEM TO BE SOLVED: To provide a battery pack having a protective circuit for preventing an abnormal temperature rise during discharge, and a power tool using the same. SOLUTION: The battery pack is provided with a battery set comprising a plurality of battery cells 109-111, an overcharge/over-discharge detection means 123 that detects an overcharged state, in which a battery voltage exceeds a prescribed charge value, on the basis of the battery voltage of the battery set so as to output each control signal LE, LD showing overcharge or over-discharge, and a temperature-sensitive switch means 107 that is provided in a charging path for the battery cells 109-111 so as to cut off a charging current by opening the charging path when a temperature of each battery cell rises beyond a prescribed temperature value. When the temperature of each battery cell 109-111 exceeds the prescribed temperature value during discharge, a charging path between a terminal 101 and a terminal 102 is opened by the temperature-sensitive switch means 107 while a discharge stop signal is outputted as the control signal LD showing over-discharge by an output circuit 140. COPYRIGHT: (C)2009,JPO&INPIT |
