Is a 270 amp alternator enough?

[rockFord_Expedition]

And in you analogy of the wattage formula, remember that amperage pulled from a battery can only be multiplied by the voltage available. If it is below your charging voltage then your alt isn't keeping up so your output number drops. So your example of 900A x 14.4V = 12,960 W is the power the amp receives, not what it puts out.

Good thread, good conversation. I like it.

That's true about the voltage dropping, what I was getting at was that you were considering the wrong amperage for that equation. Even if you want to factor in the voltage drop it'd still be 900A*12.0V=10,800 watts before efficiency and all that good stuff.

And I get what you're saying, but to answer the OP's original question-yes, a 270 is enough especially considering that's all you can fit in the vehicle lol. You just need to compensate with a bigger reserve.

As for what you're saying about the reserve only making much of a difference when the car's off and you're playing it does the same exact thing when the cars on and playing. The only difference is that you have a 'charger' charging them as you drain them. It just doesn't keep up with the drain 100%. But you do have more time to play when you have a bigger reserve regardless of the car being off or being on and alternator charging a fraction of what's being drained.

I agree. Yes the alt is enough assuming everything else is done right.

Not sure if we see eye to eye regarding what the batteries do, but I think we are close. I agree extra batteries are good, but the ONLY component keeping everything running at 14+ volts is the alternator. Whe you exceed the limits of the alternator you are then using battery power. 12V battery power. That's when you drop below the alts charging voltage.

Good stuff man.

[Zak Massey]

Right on! Now it's just to set this all in motion... Bass is an expensive ass hobby

[truthsayer]

Rockford has given very good info and advice, my theory alt can always be better. Get a mechman 370 amp 6 phase Elite series

300 rpm turn on speed

200 amps @ 500 rpm

250 amps @ 800 rpm

370 amps @ 1800 rpm

Twin rectifier plates

12 press fit high amp diodes

$749

[Miguels]

a battery charger will be your best friend in this situation. top off your batteries nightly and also turn your system down a few minutes before you get to your destination. the last thing you want to do is turn your car on with dead batteries

[Zak Massey]

a battery charger will be your best friend in this situation. top off your batteries nightly and also turn your system down a few minutes before you get to your destination. the last thing you want to do is turn your car on with dead batteries

T God that hasn't happened yet! But yeah I may have to invest in one!

[Zak Massey]

Rockford has given very good info and advice, my theory alt can always be better. Get a mechman 370 amp 6 phase Elite series

300 rpm turn on speed

200 amps @ 500 rpm

250 amps @ 800 rpm

370 amps @ 1800 rpm

Twin rectifier plates

12 press fit high amp diodes

$749

I would consider that if they had one that fit an '03 cavalier. there is a wopping 0 extra room around the alt for absolutely any differences. I know this because something very minor was different with the DC alt and it didn't actually fit.