long story short.. capacitors store energy.

when amperage is drawn from a source (battery) in huge amounts, (hungry servo's) the voltage or potential decreases, and could shut down the receiver, giving it finicky performance, or delayed response.

if your into car audio, and bass systems, and huge stereo setups, cap's, batt. caps.. are very common due to the amp draw from large amplifiers drawing current for its equipment. capacitors store the extra vars needed to support the watts needed to move the current.

lol, i know 1/2 that shit didn't make sense right.. ::shakes head::