Method for controlling charge to secondary battery for automated guided vehicle

A method for controlling charge preventing an operation of a valve during charging and suppressing the false detection of the upper limit charging voltage due to the memory effect at the charge side in a secondary battery mounted on an automated guided vehicle is presented. The method includes charging the secondary battery at a charging current value of not less than 0.5C and not more than 4.0C; detecting current that flows in the secondary battery and calculating the remaining capacity by accumulating at least the detected current; and completing the charge to the secondary battery when the calculated remaining capacity is not less than the threshold value that is pre-set to not less than 60% and not more than 95%.