How to Install a battery in a system where a capacitor already exists.
It comes down to the voltage of the battery at the time of installation. The closer you are to the voltage of the supercap the better. If your new battery is over the resting voltage of the super cap by 1V then you will get a significant spark happening. If the new battery is at the same voltage level or .5 ~ 1V lower than the supercap there would be a faint spark if any. The closer you are to the same voltage as the supercap the better.