  Understanding how electrolyte-filled porous electrodes respond to an applied
potential is important to many electrochemical technologies. Here, we consider
a model supercapacitor of two blocking cylindrical pores on either side of a
cylindrical electrolyte reservoir. A stepwise potential difference $2\Phi$
between the pores drives ionic fluxes in the setup, which we study through the
modified Poisson-Nernst-Planck equations, solved with finite elements. We focus
our discussion on the dominant timescales with which the pores charge and how
these timescales depend on three dimensionless numbers. Next to the
dimensionless applied potential $\Phi$, we consider the ratio $R/R_b$ of the
pore's resistance $R$ to the bulk reservoir resistance $R_b$ and the ratio
$r_{p}/\lambda$ of the pore radius $r_p$ to the Debye length $\lambda$. We
compare our data to theoretical predictions by Aslyamov and Janssen ($\Phi$),
Posey and Morozumi ($R/R_b$), and Henrique, Zuk, and Gupta ($r_{p}/\lambda$).
Through our numerical approach, we delineate the validity of these theories and
the assumptions on which they were based.
