Originally Posted by CODY_YARBER07
I guess what my main question is, can I get by with the old alternator?
You'd need to list all of the accessories you want to run in order to tell. The power formula is P=IE, (P is Power, I is Current and E is Volts). Nothing is 100% efficient, so unless the amps state their draw vs output, assume they're about 60%. 300W/ch is 600W total and if it's 60% efficient, that's about a 70A draw if the voltage is 14.4, more if the voltage drops (which it does at low RPM and when the alternator and battery are under heavy load.