A charge accumulating system of the present invention comprises a nonaqueous electrolyte battery unit including a nonaqueous electrolyte containing an ionic liquid, a negative electrode and a positive electrode, a temperature detector which detects an ambient temperature of the battery unit, a first controller which lowers a maximum battery voltage of the battery unit when the detected temperature from the temperature detector exceeds a standard ambient temperature, and a second controller which controls a maximum charging amount Qmax of the nonaqueous electrolyte battery unit at a constant level, or lowers the maximum charging amount Qmax when the detected temperature from the temperature detector exceeds the standard ambient temperature.