Image forming apparatus with power supply control for fusing control circuit

An image forming apparatus comprising:

• a fusing unit having a heating element to which a commercial power source is supplied and fusing a toner image on a transfer material;
• a fusing controller which limits power from the commercial power source to a limit level and supplies the power to the heating element;
• a rechargeable battery capable of supplying power to a load other than the heating element;
• a voltage regulator circuit which outputs an output voltage from said rechargeable battery upon stepping-up the voltage to a predetermined voltage;
• and
• a power supply controller circuit which controls supply of power from the commercial power source and said rechargeable battery to the load other than the heating element,
• wherein said fusing controller adjusts the limit level in accordance with a control state by said power supply controller.