| 摘要 |
<p>PURPOSE:To shorten the time required for decision of the lifetime of a battery by monitoring the discharged voltage of the battery for a fixed time in order to automatically decide the battery lifetime. CONSTITUTION:When the lifetime of a battery is decided, a maintenance control circuit 11 instructs an AC/DC conversion & input switch circuit 1 to separate an input power supply and also to discharge the batteries 9a - 9n. When these batteries are discharged, an internal pulse generating circuit 72 of a battery switch circuit 7 works to oscillate the clock pulses in a fixed cycle. Then the lifetime of each battery is decided after a fixed time. In this case, the discharging voltage curve of each battery is monitored by a battery voltage monitoring circuit 10 for a fixed time. Then the voltage curve is compared with the specifications of the lower limit voltage level of an estimated battery discharging voltage curve. If the discharging voltage curve is lower than the voltage level specifications, it is judged that the lifetime of the battery is exhausted. Thus it is possible to shorten the time required for decision of the lifetime of a battery.</p> |
