BATTERY FOR ELECTRIC-POWERED TOOL

摘要

PURPOSE: A battery for electric tools is provided to calculate an elapsed time since the battery is manufactured. CONSTITUTION: A battery for electric tools comprises a micro computer(24). The micro computer is converted into an active mode by operating peripheral circuits(21,22,26,27) in a normal service condition. In a non-normal service condition, the micro computer is converted into a sleep mode by stopping the peripheral circuits. The micro computer is regularly converted into the active mode in the sleep mode. The micro computer operates the peripheral circuits. The micro computer detects a battery state through the peripheral circuits.