The automotive thermoelectric generator (ATEG) produces electrical power by converting heat energy of engine exhaust gasses. The transfer of this electrical energy to a vehicle’s electrical system should be done with minimum losses. The electrical parameters of thermoelectric modules (TEMs), which are installed in the ATEG, are changing due to non-stationary ATEG operating conditions. This fact leads to a mismatch between ATEG resistance and equivalent electrical load resistance, causing the issue of generating maximum energy. One potential solution to this problem is a maximum power point tracking (MPPT) method. MPPT controllers provide harvesting maximum power from the ATEG. In this way, MPPT application is required for thermoelectric systems with variable heat flow. However, any MPPT controller has its own conversion losses, which affect overall ATEG system efficiency. These losses depend on MPPT controller working conditions, i.e. TEMs output voltages and currents. Therefore, the simulation of the electrical circuit should be done during driving cycles to evaluate the total efficiency of the entire system. This evaluation helps to estimate the effectiveness of each element of the electrical network. In this paper, we elaborate our theoretical and experimental studies of the ATEG electrical network and do comprehensive discussion over the design for it. © 2019, The Minerals, Metals & Materials Society.