In this publication, in addition to focusing on the engineering component in creating our own test bench for trying various modes and the overall performance of solid polymer fuel cells with electric power of more than 2 kW, the features of the result of the operation of a liquid-cooled fuel cell in the field of heat transfer are displayed. It is known that its performance and service life depend on a properly tuned water and thermal balance of the fuel cell. The problem area is described in the insufficient moisture content of the supplied air to the fuel cell and the excess heat in the fuel cell. In this case, the negative consequence is that additional resistance to the rate of the electrochemical reaction is created, as a result of which the generated power decreases. A possible way to solve this problem is proposed: so, according to the heat balance equation, by increasing the temperature difference between the incoming and outgoing heat carrier, more heat energy can be removed. The temperature difference was achieved using a water-air radiator. The increased removal of thermal energy allowed the condensation of part of the moisture inside the fuel cell, maintaining the humidity and conductivity of the membrane, but not allowing flooding of the channels with liquid water, which otherwise could lead to a decrease in performance. During the tests, it was possible to increase the removed power by 321 w, which is 8.4% in excess of the maximum power. Based on the obtained experimental results, dependencies were constructed that are expressed by the current-voltage characteristic, power curve, the amount of heat removed by the water from the fuel cell, and a graph of the change in water temperature at the inlet and outlet of the fuel cell at various stages of operation.
