actually, if you do know anything about electrical, and alternators, caps can do damage, though only when the system is already in a strained state. they do transfer current both in and out differently than a battery. batteries will "choke" the current during recovery coming back to floating voltage, and a cap will let it just flow in full bore up to the point the alt has achieved setpoint voltage. keeps the alt at full output more continuously. the effect could be seen as miniscule, but still there.
.... i'm supprised this hasn't been mentioned: "more/bigger batteries make more power"
....and, "make the power wire bigger, because it has all the voltage. only need a little ground"