Balancing of Supercapacitors

Balancing of Supercapacitors

Technical Article

Supercapacitors (SCs) generally operate at low voltages of about 2.7 V. To achieve higher operating voltages, it is necessary to build up a cascade of SC cells connected in series. Due to variations in capacitance and insulation resistance caused by production or aging, the voltage drop across individual capacitors may exceed the rated voltage limit. Therefore, a balancing system is required to prevent accelerated aging of the capacitor cell.

In the following, the effect of unequal voltage division in such series circuits will be explained in principle. For a better understanding, balancing strategies are discussed for using a series connection of two capacitors.