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Discussion Starter #1
how many amps does the b5 have on the altanator? and about how much is used at normal driving conditions without an amp or such
 

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90. Normal driving, I'd say 60 or so?
 

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What type of amp is it? Class A, class AB, class D? Or just post what amp it is. :p
 

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Don't worry about it. Amps don't have a steady current draw like a defroster or A/C condenser. I've built a lot of systems in a lot of cars and I've never *needed* a larger alternator in *any* of them. Sure, a few of the comp cars got them to get a few extra points, but they didn't need them. My wife's Jetta has a 60 amp alternator and when it was still my car I had almpst 2000 watts in it and it worked just fine. 133,000 miles later the original alternator is still going strong. Save the money and do another mod or something.


Paul :thumbup:
 

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Generally speaking when they design cars, they calculate all of the current draw for all of the standard electrical components, and then double that to determine the nessecary alternator rating. So the factory 90 amp alternator is only seeing about a 45 amp draw normally, unless you're driving with the cruise control on, your monsoon stereo on full blast, with your cd changer going, and your wipers on high, adjusting your seat, have the heater on high, with your seat hearter on high as well, and also the rear window defroster.....and you're rolling your windows up and down and up and down. lol.....I thinkyou'll be doing just fine to add a 700W amp.

If that amp is 70% efficient then at most it would draw about 65 amps at 13.8V. The problem comes when you are straining your system so bad that the voltage drops too low, and consequently the demand for current goes up. This is when you either blow a fuse, or worst case damage electronic devices because of lack of power...It's amazingly unlikely in a situation with only a 700W amp, but that could be good information for you to know if you do plan to keep adding amplifiers in the future.
 
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