NOVELTY - Present invention relates to electrical engineering, particularly to a power installation with an electrochemical generator. According to the invention, the power installation has an electrochemical generator, voltage converter, whose inputs are connected to the terminals of the electrochemical generator, and the outputs are meant for connection to a load, control system of the electrochemical generator and the voltage converter. The terminals of the electrochemical generator are connected to a diagnostics unit, which comprises a voltage sensor and a circuit of series-connected key element and a current sensor, all connected to the terminals of the electrochemical generator, and a control unit, the inputs of which are connected to the outputs of the current sensor and the voltage sensor, and the outputs respectively connected to the control input of the key element and the on/off input of the voltage converter. The method of controlling the power installation involves converting voltage of the electrochemical generator to voltage of a given shape and level using the voltage converter. The modes of operation of the electrochemical generator and the voltage converter are controlled using the control system. Periodically at a given time, the voltage converter is disconnected from the electrochemical generator. The terminals of the electrochemical generator are closed and opened. When the terminals of the electrochemical generator are closed, short circuit current is measured, and open circuit voltage is measured when the terminals are open. The values are compared with given values. If the short circuit current and/or open circuit voltage is below the value, the terminals of the electrochemical generator are periodically opened and closed at a given frequency and pulse ratio until the current or voltage reach the given level, after which the voltage converter is connected to the terminals of the electrochemical generator.    USE - Electrical engineering.    ADVANTAGE - Increased reliability, improved energy characteristics and operational life of the power installation. 2 cl, 2 dwg