? About Amplifier Power Supply

[the wrath]

I Want To Know If I Have A System That Is 200amps Total And I Am Running 2 Yellow Top Optimas One In Front One In Back And A 2.4 Farad Capacitor And A 140 Amp Alternator Am I Going To Kill The Alternator Should I Eliminate Something Or Add Oh I Am Running 0 Gauge Wire Ground And Power My Lights Still Dim I Tried A 200 Amp Alternator But It Doesnt Produce Enough Amperage At Idle

 

[6APPEAL]

I for one have never liked the Optima batteries. They never held up in any system they were put in. I alway had great luck with Champion and Duralast (Autozone) batteries. I never used caps in any system I installed either. An extra battery would handle the load much better. I don't think you'll find any alternator that will keep up with your max system load at idle. Alternators are not designed to put out that amount of amperage at idle speeds.

The 1st thing I would look at is the ground. Make sure it is a good clean connection on the frame. Also check you ground from your front battery. Check the voltage from your alternator and look at upgrading the charge wire to a larger wire guage. Were your batteries bought at the same time? If one is much older than the other, you will only get as much power as the average of the two. This will get you by without spending any money. You could try replacing the cap with another battery. HTH
John

 

[grocerygetter]

you are pulling 200 amps at idle? That's full tilt volume?
you can get a GM large case altenator tweaked to do that at idle...it won't do very well at WOT shifts frequently though. I would say get a custom alt...around 150 idle current and get a couple of nice Kinetic batteries. Forget Optima.
I just can't believe you are pulling that much current at idle...if so, you're def or have some very inefficient amplifiers. Sorry. What I'm getting at is that if you have an amp that has 60A of fusing in the end of it...that thing may only pull 10 or 15 amps at normal listening volume.

 

[the wrath]

what i did was add up all of the fuses on both amps to get that 200amp rating and who makes a alt that produces 150 amps at idle

 

[6APPEAL]

No normal alternator supplier makes an alternator that will do 150 amps at idle. As Grocerygetter said, you will have to get a custom built alternator. You might succeed in burning up the electrical system in the car with an alternator that big. If you want to be able to sit around and pound on the system at idle, forget using any of the electrical system in the car. You need to build a seperate charging system/electrical system for the stereo that uses a custom battery bank of 4 - 8 batteries. I done this many times in systems I've built for folks that turned the knob wide open, then ripped it off. Most of them are deaf now, but they have extremely loud systems (150+ db). I'm not trying to be sarcastic, just trying to explain physics as simply as possible.

 

[grocerygetter]

the only way you won't burn up your elec system when buying a custom altenator from someone like Ohio Generator or Wrangler is to adjust the regulator so that the thing won't charge over 15 volts...so I'd say go externally regulated. I think you are under a bad misconception though with how big of an altenator you acutally need. You realize you are getting ready to spend $350-800 for an altenator? IMO...get a GM large case off a Tahoe or something with a little more output than ours have and run two batteries...two good size batteries. Minimum two 800cca batteries.

 

[soundguy]

ok. first. How do you come up with the I'm pulling 200 amps? 200 amps in a stereo system equates to approx 5500-6000 watts of power. Analog amps are about 30% efficient which means only 30% of the current pulled reaches the speakers, other 70% goes up in heat.
To the reply about not using a cap since a battery will handle the load better, capacitors are not used to handle load. they are used to "stiffen" the low end response because batteries simply cannot deliver current as fast as a bass note spike (typical musical amperage draw) requires. Lack of a cap on higher power systems gives that "muddy" bass sound. The cap simply stores the energy and releases it to the amp instantaneously then recharges each musical peak.
As for alternator requirements, forget it. in order to keep your engine running, you would not only need that 200 amp output, you would still need approx 60-80 amps depending on how many electronics the car has. Without that, you are drawing on the battery and will soon kill it. The old school fix alot of competition people did that pushed 10k watts plus was to have dual alternators. One would handle all car funcions and the engine. The second was dedicated to the stereo system. Of course this means fabricating custom mounting brackets and pullies to drive the second alternator.

 

[the wrath]

hey soundguy this is what i am running i am running a jbl 1200.1 mono amp and a power acoustik 960 watt 4 channel amp and the lights still dim i have added a 4 guage ground to the battery to the body too that helped but didnt solve the problem one amp s 1200 x 1watts rms and the other is 100 x 4 rms

 

[the wrath]

i was just wondering if i should take out one of the yellow top batterys and just leave the cap in the rear

 

[soundguy]

Only thiing dual batteries is gonna do for you is buy more time before they die. Any more amperage draw than the alternator can supply is taken from batteries. The cap in the rear in NO way provides more available power, it simply supplies its stored energy much faster than any battery ever will ( capacitors discharge in microseconds) during those bass spikes in the music. If you hear a high volume system that sounds muddy and the speakers aren't bottoming out like alot of peeps drive them to, its cause the electrical system couldnt supply enough amperage fast enough for that musical peak.
Only way I see you running reliably is to have a custom alternator wound and mounted as a secondary unit , leaving the stock alternator to drive everything else in the car. Also, if you do this, run the head unit off the same alternator and battery as the amps, not the car's electrical. If you do all you are doing is causing a ground loop between 2 seperate electical systems, and this can lead to alot of unpleasant side effects.

 

[grocerygetter]

Everyone has opinions...mine considering your system isn't that big is to buy a dual output 150-200 amp altenator (GM Large case). Use one post for the normal stuff on the car and the main battery. Use the other post for the other battery or batteries in the trunk. Run all of your stereo off the dedicated 'stereo' batteries. All of the batteries in the vehicle need to be the same.
Rule of thumb...1 cold cranking amp for every RMS watt of output power for serious systems. (that is above and beyond your car's requirements). This is what most competition type SPL set ups use. I think it is overkill in your situation...but, you'll be able to jam on it.

 

[GNandTTA]

You are forgetting that just having a battery hooked up draws power. Roughly 15 amps depending on battery size and condition. I myself love Optima's specifically the yellow tops. Last one I had lasted 9 years. No regular conventional battery can do that. The best thing is to keep the batteries in or very near the engine compartment. All batteries charge better in a warm environment. That is part of the reason why cars have trouble starting in the winter, besides thick oil obviously. I'd keep just one yellow top upfront in the engine compartment. You would be OK keeping the factory alternator and using a solenoid to create isolation between the batteries when the car is off. I've had this setup since purchasing my TTA in 91' and never had any problems.