Patent ID: 7254353

Claim:
A control method for an image forming apparatus including a fusing unit having a heating element to which a commercial power source is supplied and fusing a toner image formed on a transfer material, a rechargeable battery capable of supplying power to a load other than the heating element, a power supply controller which controls power supplied from the commercial power source and the rechargeable battery to the load other than the heating element, and a fusing controller which limits power from the commercial power source to a limit level corresponding to a control state by the power supply controller, comprising: a destination temperature detection step of detecting a temperature of the fusing unit at turn-on or upon returning from an energy saving mode; a first adjustment step of causing the power supply controller to supply power from the rechargeable battery to the load and causing the fusing controller to increase the limit level accordingly, when the temperature of the fusing unit which is detected in the temperature detection step is less than a predetermined temperature; and a second adjustment step of monitoring the temperature of the fusing unit which is detected by repeating the temperature detection step while power from the rechargeable battery is supplied to the load, and when the temperature of the fusing unit is not less than the predetermined temperature, causing the power supply controller to supply power from the commercial power source to the load, and causing the fusing controller to decrease the limit level accordingly.