BATTERY PACK FOR POWER TOOL, CONTROL CIRCUIT, AND PROGRAM

A battery pack for electric power tool is provided with a battery and a control circuit. The circuit includes a condition satisfaction determination unit, a continuation satisfaction determination unit, and a sleep-mode transition unit. The condition satisfaction determination unit determines whether each of at least one predetermined sleep-mode transition condition is satisfied, and determines whether an all-condition satisfaction state is present, which is a state wherein all of the at least one sleep-mode transition condition are satisfied. The continuation satisfaction determination unit determines whether the all-condition satisfaction state has continued for a predetermined period of time when the condition satisfaction determination unit determines that the all-condition satisfaction state is present. The transition unit stops part of operation of the circuit to shift the circuit to a sleep mode when the continuation satisfaction determination unit determines that the all-condition satisfaction state has continued for the predetermined period of time.