Voltage problems of supercapacitors

Supercapacitors will be charged and discharged in series according to the internal capacitors under the condition of plugging in. This charge and discharge current is called leakage current, which endangersthe life of the lithium battery of the supercapacitor module . Similar to some new secondary batteries, the working voltage of supercapacitors must also be balanced when applied in series. Due to the leakage current of supercapacitors, the size of the internal capacitors in series determinesthe working voltage distribution on the supercapacitor modules connected in series.

When the working voltage of the supercapacitor is stable, the working voltage on each module will change with the leakage current, not with the resistance. The larger the leakage current, the smaller the rated current, on the contrary, the smaller the leakage current, the higher the rated current. This is because the leakage current will lead to the charging and discharging of the supercapacitor module, reducing the working voltage, and this working voltage will then endanger the working voltage of other modules connected in series with it. Apply the same stable working voltage power supply system.         

In order to better compensate the leakage current change, the commonly used method is to connect a resistor in series with each module to control the leakage current of all modules. This kind of method reasonably reduces the series transition of the corresponding capacitors in the middle of each module. Another highly recommended method is the active module equalization method. Using this method, each module will be actively monitored, and when there is a change in the operating voltage, it will be balanced with each other. This kind of method can reduce all the additional loads on the module and further improve the work efficiency.