The article describes the device for telemetry and control of the technical state of chemical current sources. The controlled parameters are the residual capacity, voltage, discharge current, temperature of current sources. The article presents a functional scheme of the device, its feature being galvanic isolation of the current source circuit and the monitoring device. To provide galvanic isolation, the authors propose a circuit solution for non-contact current measurement in order to reduce the error in measuring currents of various magnitudes. An asynchronous parallel-serial data transfer interface is used for the exchange with the upper-level system. The article describes the algorithm of telemetry device operation, which is implemented for the 1887VE4U microcontroller. When developing the device, the main difficulty was the need to ensure the minimum weight and dimensions and use only domestic-made electronic components to comply with the import substitution strategy in the Russian economy.