[suicideneil]

Pleb head.

Look up capacitor on google or wiki- it'll explain what is is and does- its basically like a mini battery that stores current, then releases it (quickly) when its required. It also helps to absorb ripple currents that can harm the esc from the batts. You can solder it to the deans, but ideally you want it as close to the esc as possible to get the most benefit- you can see how people added cap banks to their esc from lutach in his HV esc thread for a better idea.