Which capacitor would I need in order to dump 150-175 amps ~12vdc for ~2 seconds?
i hate to tell your wrong but. most all modern alternators are strait dc. if you pull one apart there are 6 diodes 3+ and 3-. the battery is there for starting and to supplement power when the load exceeds the alternator output.Basically that is what the battery in your car does, your alternator does not make straight DC, but pulsating DC, and the battery acts as a capacitor to straighten that pulsating DC to more of a straight DC, if you are worried about weight on a racecar keep the battery but make it a Braile or one like it, these new batteries are so light you could throw it across the room! Dave