I recently upgraded my audio system, but after I done this, I have noticed in the higher volume my lights start flashing- what eventually means the car audio drains too much power from my alternator. I have visted the car audio shop, they have told me just one of my amplifier drains nearlly all power available from my alternator, what I think it is about 75 Amps. They advise me to upgrade my alternator from 150 to 200 Amps. And this is the point when I cant find any designed alternator for my car( Jaguar s-type 2003, 4.2 l base). I dont think I got enough space to fit 2 alternators either.

Would any of you could advise me some kind of alternator with 200 amps, what I could easily adaptate to my car.

 

Um... don't think that's an option... sorry..

 

From my time powder coating I have a good friend who builds high output alternators. This guy is very good, but not cheap. But nothing in this field is.

High Amp Alternators, Hi output dual alternators, spl-comp alternators, and other custom auto-electrical products. all with free shipping at Rush Power Systems

 

Have you tried a capacitor?

 

The battery is acting as a sort of capacitor- but apparently it's being drained to the point that the lights are dimming.

I've always wondered when I see (actually hear) one of the cars going by- how can the occupants hear anything going on outside like ambulances, police, fire siren etc. Maybe the dimming lights are a cry of help from the car?

 

Yeah I know. I mean a capacitor in addition to the battery. IIRC the PCM controls the output of the alternator. So even if he were to get & install a HO alternator, the cars electronics would be trying restrict the output to factory levels. Maybe a tune would help, but I'm not so sure. If it's just for an amp & bass-box combo, I would think that it would be better to use an in-line cap to feed it. I could be wrong though...

 

If this were to be a problem, he could just run separate voltage regulator like old style cars.

 

If he "needs" more power a capacitor won't help.

 

I got a boss capacitor with 35 farads, but it seems do not make any difference. I asked for it in the audio shop and they said the capacitor do more damage than profits, becouse it drains power as well.

By the way, I found online the formula: If I got the battery with 90AH and alternator with about 75 amps:
90AH x 13V =1170WH
1170 x 0.7 = 819V

then I got 2 amplifiers one with 2400w, and second with 1600w, whitch gives me
4000 w

4000/0.7 = 5714,3
5714.3/13v = 439.6A what I need to power my system

Becouse I got 75A alternator and it uses mostly 60% for the car then:

75A x 0.6= 45A

In total 439.6A -45A = 394.6 A
This looks I need 400AH battery to helps me out with the system and this do not include charging this battery up.

 

I think the standard S-type battery is 700AH or more, so a 400 is the wrong direction.

 

I believe he is talking in addition to the stock bat.

If you can install/ work on car electronics on your own, there are some things to do before putting in the bigger alternator.

1 st check to make sure the power and ground cables are of good quality, and the correct awg for how much power you are using. Make sure there are no lose connections, and that there are the minimum number of connections in the power and ground wires. Each connection is about a .2 voltage drop, even if made correctly. make sure the ground wire is as short as possible, and grounded to bare metal that has been scraped off with a wire brush in your drill ect.

Do the "big three" Which involves upgrading the wire coming from the alternator +, the battery to ground, and engine ground.

If you look around on the 12volt you can find lots of info on what I'm talking about.

 

It's maybe easier to work in A (amps). The alternator you already know in A. The battery can deliver up to maybe 600A but only briefly (seconds) and the volts will drop. It can't deliver anything at all on the average because you'll flatten it, so ignore it and just consider the alternator.

2400W amplifier is roughly 200A (at 12V) if run flat out. It is also a crazy thing to fit in a car!

I understand an orchestra playing flat out is under 10W so to need a 2400W amplifier means either something very weird or staggeringly inefficient speakers.

 

I think you're right, but additional batteries won't forestall the inevitable. The OP's sound system is extracting power from the alternator faster than it can be replaced. Dead car on the side of the road is inevitable. I'd just turn the volume down to something reasonable but that's not the point.