Patent ID: 8148994

Claim:
A device for determining replacement of a storage battery comprising: charging means for charging not less than one storage battery as a determination target; voltage measuring means for measuring a voltage change value of the storage battery in a predetermined period of time after the end of charging the storage battery; and temperature measuring means for measuring a surface temperature of the storage battery at the end or an intermediate interruption of charging thereof; derivation means for obtaining a relationship between the surface temperature of the storage battery measured by said temperature measuring means and the voltage change value of the storage battery; calculation means for calculating a reference voltage change value based on the relationship between the measured surface temperature and the measured voltage change value of the storage battery and based on said measured surface temperature when the residual capacity of the storage battery is less than a replacement reference capacity; and determination means for determining that the storage battery needs to be replaced, when the voltage change value has become not less than a reference voltage change value consecutively a predetermined number of times which is not less than one.