The invention relates to the field of electrical engineering. An electricity supply system for a transport vehicle contains an electric network (1) with negative and positive wires, to which are connected an accumulator battery (2) and an electric starter (3); a capacitor bank (4); a bidirectional converter (5), which is connected between the capacitor bank and the electric network; a regulator (6); and a temperature sensor (11). Voltage from the capacitor bank is fed to an input (10) of the regulator, an additional input (12) of the regulator is connected to the temperature sensor, and outputs of the regulator are connected to control inputs (7, 8, 9) of the bidirectional converter, which bidirectional converter, in accordance with a signal at the control inputs, is capable of changing the parameters of its own volt-ampere characteristics at the outputs on the side of the electric network. The regulator is carried out in a way that the maximum current flowing from the bidirectional converter to the electric network is a decreasing function of the temperature-sensor temperature. The invention extends the service life of an electric starter and enhances the reliability of an electricity supply system.