170 amp alternator

I have a 170a alternator. How Do I calcutate how many amps I can draw off the alternator. I want to run a 2200watt system. Will 170a alternator and a kinetic battery be enought.

Hmm. Amps = Watts/Volts 183 = 2200/12 Now this is sort of a tough question. This depends an awful lot on a number of things... far to many to really give you an adequete answer. My inclination is to tell you that with a deep cycle battery and an alternator that big, you ought not have big problems.. even with a draw like 180 amps... (keeping in mind that you might as well increase that to 225 - 250 accounting for amplifier inefficencies) .. you certainly aren't going to be pulling that all the time.... Of course, your alternator is not going to be producing 170A all the time... generally alternators reach full output somewhere slightly above a crusing rpm.. So eh.. your in the right neighborhood but this really is kinda one of those things you have to hook up and find out. "I'm finished!" - Daniel Plainview

alternators dont run at 12 volts, they generally run a little above 14 volts

Hmm. Amplifiers are *not* going to be seeing a constant 14.4v, particularly under the load of 2200watt stereo. Just because the alternator's native voltage hovers a hair above 14v doesn't mean that is what his stereo will see, or, for that matter, what his vehicles voltage will be. Like I said, lotsa stuff plays into this. Ultimately, math really isn't the point. He'll still have to hook it up and find out."I'm finished!" - Daniel Plainview

adix5689 wrote: I have a 170a alternator. How Do I calcutate how many amps I can draw off the alternator.

There's no calculation here.  It's a 170 amp alternator.

Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

I want to run 2200rms on a 170amp alternator.

OK, Pay attention, this is testable material : 2200 watts (OUT) times 1.33 = 2926 watts (IN) divided by 12 volts (nominal, NicP) equals 243.3 amps. Does 243.3 amps "fit" into a 170 amp alternator? No. are you going to be running 2200 watts ALL THE TIME? NO, and I GUARANTEE that... I have close to 6kW in my trunk, and I am using a 165A alternator... not a single problem. BUT, to answer your question in an absolute fashion, no, it will not be big enough. sedate told you there are mitigating circumstances to this answer, and I have told you that I am running FAR more than one woud think would be possible on my alternator... (Also keep in mind this 170A is probably a clod rating - you need to derate by a MINIMUM of 10 to 15% for hot output...)It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Youre more correct than you think about being testable material ;) Why would you use 12 volts? most amplifiers are rated at 14.4v, if you use 12 volts it is most likely that the amplifier will not be putting out 2200w But as everyone else said there are too many factors to give you a calculated answer, we dont know how much of the power the car and accessories will be using, we dont know the inefficiency of the amplifier (thus how much current it will really draw) and we dont know what the realistic output of your alternator will be Having said all that itll probably be fine you dont plan to drive around with 2200w of power and have it on full volume all the time now do you?