Method for controlling the emergency power supply and the emergency power supply system, in particular for a vehicle occupant protection system

An emergency power supply system for a vehicle occupant protection system, comprising:

• at least one control unit;
• a firing device associated with an autarchy time period;
• a first energy storage device for supplying energy to said control unit;
• a second energy storage device for supplying energy to said firing device;
• a controllable switch;
• and
• an energy source for supplying energy to said first energy storage device and to said second energy storage device;
• when said energy source fails, said first energy storage device and said second energy storage device supplying energy to said control unit and to said firing device during predetermined autarchy time periods;
• said control unit associated with an autarchy time period being longer than the autarchy time period associated with said firing device;
• and
• said controllable switch for connecting said second energy storage device to said first energy storage device so that residual energy available in said second energy storage device is available for supplying power to said control unit.