Circuit for storing electrical energy

The storage circuit (10) has capacitors (12, 14, 16, 18, 20, 22) i.e. double-layered capacitors, and a positive temperature coefficient thermistor (24), which charges the capacitors and defines current flow during a charging process. A diode (32) discharges the capacitors without current limitation by the thermistor. The capacitors and the thermistor are arranged on a lead frame. The thermistor regulates charge current independent of a charge condition of the capacitors. A resistor (30) is provided parallel to the thermistor. An independent claim is also included for a method for retrofitting a motor vehicle.