You can set up a fix the current density experiment. You might fix the current density and set enough potential range(you can get potential range from CV results) for the maximum working potential of working electrode to undergo self discharge.  The galvanostat uses a three electrode system, in which a current is applied between the auxiliary and working electrodes, and the potential of the working electrode (measured with respect to the reference electrode) is monitored. The basis of controlled current experiments is that a redox (electron transfer) reaction must occur at the surface of the working electrode in order to support the applied current.  The parameters of potential range including than the maximum working potential of working electrode required for a discharge experiment and the current value and the time must be set..

Alternative to what is explained above, we apply and hold the maximum potential of the working electrode for a fixed time which is approximately twice longer than the time for charging the working electrode to the maximum potential in a GCD experiment. This potentiostatic pre-conditioning process is to ensure the working electrode is fully charged, and avoid any unwanted damage to the electrode materials due to overcharging. After that, the circuit is disconnected, and the working electrode potential is monitored against the time. In this way, the decay of the working electrode potential is in a linear relationship with the amount of charge remaining in the electrode.