Introduction. For the efficient use of non-traditional and renewable sources of electrical energy, it is necessary to ensure their operation at the maximum power point, which is possible if the load resistance is equal to the output resistance of the source. To match the load resistance with the output impedance of the source, a matching switching regulator is connected between the source and the load. Very often, the amount of energy received from such sources depends on external conditions. To ensure a uniform supply of electrical energy to the load, a battery operating in buffer mode is connected at the output of the switching regulator. Problem. In this case, the load of the switching regulator is the battery, and the input impedance of the regulator will perform the role of the load of the power source. This resistance depends on the voltage of the battery, the type of switching regulator and its mode of operation. In such cases, the maximum power extraction mode from the source can be provided by selecting the appropriate operating mode of the switching regulator. The aim of the work is to analyze the conditions and determine the modes under which the transfer of the maximum possible amount of electrical energy from the source to the battery is ensured, as well as the features of the switching regulator in these modes. Methods. For this purpose, the regulating characteristics of step-up and step-down switching regulators were determined and analyzed, taking into account the presence of an accumulator at their output. Taking into account that in the maximum power transmission mode, the output resistance of the source and the load resistance are of the same order of magnitude, when determining the regulating characteristics, the internal resistance of the source was taken into account. Results. As a result of the analysis of the obtained regulating characteristics, the conditions were determined under which the transfer of energy from the source to the battery is ensured, and the parameters of the operating mode of the switching regulator were determined, under which the maximum power will be taken from the source of electrical energy. Novelty. The originality of the work is the consideration of the internal resistance of the source of electrical energy in determining the regulating characteristics of pulse regulators. Practical value. The obtained results made it possible to indicate the appropriate range of battery voltages for different types of pulse regulators, as well as to give practical recommendations for choosing the mode of operation of the pulse regulator depending on its type, as well as the amount of voltage on the battery.