Alternator amperage.

[97chameleonbird 10+ year member]

If an alt says it puts out 300 amps max and 100 amps idle how does that work?

If my system needs a 300 amp alt would it be fine at idle? Im not too sure how they work, still working on gaining some knowledge.

Send me your teachers!

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[InfinitePeace 10+ year member]

Most HO Alternators just don't put out as much at lower RPMs, which is why you have good batterie(s) to pick up the slack. It really depends on what you're running though. If you're looking at 300a alternators, you're going to need extra batteries anyway.

 

[97chameleonbird 10+ year member]

I was planning on running a FI BTL 2000watt rms sub with matching amp alonng with a 6 speaker system off of a 6 channel amp. I will have a kinetik battery(the biggest one they have, 2400 or something like that) dedicated to the audio and probably an optima battery up front. should this be able to work when my system needs a 300amp alternator and it idles at 100?

 

[audioholic 5,000+ posts]

Not only will you not need a 300 amp unit, I wouldn't recommend one that big. The bigger the alt gets, the worse its idle capacity tends to be. I started off looking at 300 amp units too, and settled on a 260 amp because its idle performance was better.

An alternator creates energy from the motion of spinning (think the opposite of an electric motor). The faster it spins, the more power it can create, to a point. Hence when the engine is running at 'idle' RPM's (usually 500-1k rpm), the alt's output capacity is less than at higher rpm's. The dual ratings is a way of giving potential customers more information than a simple max output capacity under ideal conditions.

 

[IgnoreMe 5,000+ posts]

If an alt says it puts out 300 amps max and 100 amps idle how does that work?
If my system needs a 300 amp alt would it be fine at idle? Im not too sure how they work, still working on gaining some knowledge.

Send me your teachers!

if that alt puts out a true 300a, and a true 100a at idle, thats pretty **** impressive. most 200a units put out around 100-120 at idle anyways. mind supposedly does 120 and its a 200A unit.

 

[97chameleonbird 10+ year member]

well what would be reccomomended for my system? 2000watts for the sub and sub amp. however much a 6 channel amp would be (not sure what im getting for that yet) for my speakers. and ill probably be running a car computer with that also.

 

[IgnoreMe 5,000+ posts]

well what would be reccomomended for my system? 2000watts for the sub and sub amp. however much a 6 channel amp would be (not sure what im getting for that yet) for my speakers. and ill probably be running a car computer with that also.

depends on the price. im a big fan of "buy the biggest that you can afford, so long as its quality". you wont need a 300a unit for 2kw, i can tell you that though.

what company are we talking about anyways.

 

[terra 5,000+ posts]

why not run more power on that btl? then you can really use the 300amp..

 

[97chameleonbird 10+ year member]

isnt the btl rated at 2000 rms?