Charging at Constant Cell Voltage

This suggests that even if the supercapacitor is fully charged, extra current density is still needed to overcome the self discharging caused by R. However, if the leakage reaction does not occur, i ai can be simplified 

In this case, the charging current will approach zero when t that is, i-ceii 0/ suggesting that no extra current density is needed to overcome self discharging. In practice, is normally much larger than that is, Rp R 5 so Equation (2.38) can be simplified to Equation (2.40). 

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