Understanding How to Measure Supercapacitor Leakage Current


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A supercapacitor has a very high resistance, but it still has a leakage current. The leakage current is equivalent to the charging current required to maintain the supercapacitor at the specified voltage value. This leakage current’s measured result will be influence by the temperature, the voltage at which the device is charged and its aging conditions.

Most supercapacitor datasheets show their leakage current performance at a rated DC voltage applied and at room temperature, such as this AVX’s SC series supercapacitor’s information for example.

The following example shows how to measure the value of your supercapacitor’s leakage current by using a multimeter with high internal impedance across a resistor.

DCL%20test

  1. Charge your supercapacitor at the datasheet rated voltage at room temperature for 72 Hours
  2. Disconnect the parts from supply voltage by opening the switch, SW (Stabilize for 10 Minutes)
  3. Measure the voltage across a known valued resistor (1K Ohm)
  4. Calculate leakage current = V/R

For more supercapacitor technical information, please check out the following threads: