Patent ID: 6545449
Filing Date: 2003-04-08
Classification: B60L,H01M,H02J,Y02E,Y02P,Y02T

Abstract:
A method for controlling charge to a secondary battery for an automated guided vehicle, the method controlling a charge amount of the secondary battery mounted on the automated guided vehicle and used as a power source of an electric motor for running, the method comprising:charging the secondary battery at a charging current value of not less than 0.5 C and not more than 4.0 C; detecting current that flows in the secondary battery and calculating the remaining capacity by accumulating at least the detected current; completing the charge to the secondary battery when the calculated remaining capacity is not less than a threshold value, which is pre-set to not less than 60%, and not more than 95%; detecting a temperature of the secondary battery; detecting an output voltage of the secondary battery; calculating a voltage gradient of the detected output voltage with respect to the time; and completing the charge to the secondary battery when, excluding the time right after the charge is started, the calculated voltage gradient is not less than a first threshold value corresponding to the detected temperature and the detected output voltage is not less than a second threshold value corresponding to the detected temperature.