Performance analysis of a lead-acid battery/supercapacitors hybrid and a battery stand-alone under pulsed loads

The effect of lead-acid battery/supercapacitors combination on battery service life is addressed in this paper. With the help of a cycling bench, accelerated aging tests of VRLA batteries were carried out. Pulsed power and smoothed power profiles were applied to the battery under 40°C. These tests reproduce the battery operation with and without supercapacitors hybridization. For the hybrid system, the supercapacitors smooth the power applied to the battery which in turn charges the supercapacitors at a low load rate. So, the supercapacitors satisfy significant peak power demands of the application. After 150 of pulsed power cycles, a decrease of 20% of the initial battery capacity was observed indicating its end of life. On the other hand, smoothed power applied to the battery enhances with 1.7 times its lifetime compared to a stand-alone battery. The fade of the battery capacity and the increase of the internal resistance are shown to be slowing down. In our study, the improvement of battery service life was experimentally quantified, which represents the novelty of this work.