I have ordered a 2.7V 500F double layer capacitor and as it makes its way to my workshop, I wish to prepare myself with some mathematics.

If charging to 1 time constant can be approximated as

Power * Time = (Capacitance * Voltage^2) / 2

And if 5 time constants the capacitor is nearly "full" (do real capacitors ever fully charge or deplete?)

How would I go about controlling the time parameter to find an unknown capacitance, providing that I am able to control and measure the other parameters.

Thank you and I hope this day finds you well.

Regards,

Mark