Brand New on ebay for 120 plus shipping. Anyone use one, are they any good, yadda yadda. Looking to upgrade. Wish I knew of a kit to just rebuild and upgrade mine....

No,

My $0.02, get yourself an PowerMaster ALT. I would not buy autoparts off of EBAY.

I GOT A 140AMP ALT FROM EBAY.. AND I CRAPPED ON ME.. I WOULDNT BUY ANOTHER ALT FROM EBAY..

same here, ebay, crapped after a year.

Early death may or may not point to a problem in the alt itself. What typically dies in an alternator is the regulation circuitry. These off-the-shelf-type alternators (this includes most of the high-current models) are NEVER designed for a 100% duty cycle, but that's exactly what they get from high powered audio amps. Now...I don't know if that's your setup, but if you're buying a 180A alt, then I'd expect as much. My current audio amp has a potential draw of 270A. A 90A alt (which I *think* is our standard in late 80's-early 90's models) normally only has to come online to recharge every few minutes; depending on the load of the car which varies based on a variety of factors. What I'm saying is...the regulators never have a chance to cool down when they're in constant use. For setups like mine (& even my old one rated @ 80A), the alt regulators never get a chance to shut off and the device fails in short order. On my older system, I'd replace an alt once a year. If I was lucky, it would happen within the warranty and I'd get a free year. I was 18 and delivery driving. I had my radio cranked about 70-80 hours a week; about 10 hours at a time. I'd consistently get right at a year -- just like clockwork.

The point of all this is: the e-bay alt may be crap or it may not. The fact that it died within a year is not all-inclusive to the fact that it may have been crap. That said...I'd have my old alt core professionally rewound for high current and have an extra alt on hand to swap out when the current one died from my audio system.

You are full of it. If what you were saying is true, then most alternators would only last a few years. The fact is when your car is running the Alt. not the battery is constantly supplying current to all electical devices. The only time that the battery every gets drain, is when you start your car. If your alt. cannot supply all of the current needed to supply power to all of the electical devices, then the power has to come off of the battery.

So whenever the engine is running, your alt is working.

The orginal GM alt. that came on my 82 lasted for 100,000 miles. On my first failure, I replace the diode bridge and regulator, and it lasted till 1998 when I installed the TPI 350 204,000 At that time I went with a higher current Advance Alt. because of the extra electical load from the dual fans, fuel pump etc. Since 1998 until this past year, I have replace the alternator about ever 18 months. I have finally went with a PowerMaster. The main problem with the Advance Alt. is when heated up, they would no longer put out the current. I don't have the heating problem with the PowerMaster. And PowerMaster gets plenty hot.

So the moral of the story is, if you want dependable electical, don;t but cheap after market parts. Go with the OEM or get a PowerMaster.

You stated it most directly when you said "I don't have the heating problem with the PowerMaster. And PowerMaster gets plenty hot. " GOOD aftermarket parts will have upgraded rectifier/regulation circuitry. Just because a part gets hot does not mean it's overheating. Overheating is stated in the spec sheet of the part in question. These devices are not 100% efficient meaning that some of the power they process is always lost as heat. The more power they process; the more power they lose; the more heat is generated. Your statements are in part correct, but not wholly unless you can show me an LDO regulator which is 100% efficient. Believe me, you will not find one. This is one of the MANY reasons why higher current loads cause these devices to fail more early than normal loads. If you don't believe me, read up on the theory and practice of these semiconductors and you'll see for yourself.

Also, as I said before, it's typically the regulator which goes out. You demonstrated that your factory unit lasted 100,000 miles and the replacement circuitry lasted 104,000 miles at which point you proactively replaced it...sounds about right to me.

My alternators which only lated a year were OEM -- I just stressed them past their specified limits.

Perhaps to be more forthcoming, I should have edited my previous statement to say: "What I'm saying is...the regulators never have a chance to cool down when they're in constant *HARD* use"

I do fully agree with your statement: "...if you want dependable electical, don't but cheap after market parts. Go with the OEM or...".

And as a final word: you can be more respectful. I'm all for the truth even if I am to be proven wrong, but you sound as though you have some other agenda. If so -- keep it to yourself.

let me simplify this without writing a book.

my car is performance only, no BOOMBOX in the back, just all american muscle. i hoped something that strong wouldn't give me a problem with my electrical equipment and keep me rolling a little longer. HAH, i was wrong.

yo phlax, you talk about showing respect my man, but when you jump on a forum talking like your the *** of what is being talked about and typing a bunch of nonsense that we already know, someone is bound to get a little upset and take it the wrong way. we've all had our experiences we're just sharing them not describing how to build one. and by the way, i never seem to have a regulator problem, just the bearings seize and my belt burns.

My 2 cents

Capacitors are not just for big booming sytems, if you are expecting a huge draw on your alt. from a sound system to a radically modded car i would try to install a cap. Couldn't hurt.
Not that i have tested that theory but the way a cap works is it feeds the system when the system drops below a certain Volt/amp setting. If you are looking for extra energy i would try that.

I don't know really.

L8R,
J.P.

This link should answer most basic charging system questions.

http://www.bcae1.com/charging.htm

I'm just trying to help. In my first post, I may have come off as a bit too verbose and if so, then it's probably because one of the things I do at my job is author technical manuals and I have the explain things such as this all the time in a vcery matter-of-fact way. Sorry if I came off the wrong way. In my second post, I did have an attitude and what set me off was the comment, "You are full of it.". That's just rude. It's OK to disagree with someone; just have a little tact.

That said, no one had previously mentioned that it was the bearings which died. Since this was a conversation about higher power output, I assumed that was what was dying. If the bearings are going out, then either the alt was out of line with the rest of the pullys on the belt system or the belt was too tight or the bearings were crap to begin with.

12V x 270A = 3240 Watts

14.4V x 270A = 3888 Watts

Are you sure about this? Thats a lot of watts.

If you are pumping that kind of power 100% of the time, say goodby to your hearing.

One thing to keep in mind is that these amps used switching DC-DC supplies and are PWM modulated based on the amount of power needed to reproduce the signal. Under average conditions you may only be drawing ~5-20 amps. The max current rating are for full power output. This current when demanded by your amp, can be supply by your battery without any problems.

Actually high current spikes can have problems. If you dont have another battery or a cap right next to your amp power inputs, you will see your volts jump up and down. And probably kill your alternator eventually.

And I disagree, because.
The voltage of the circirt will never fall below the battery voltage. The fact is the requlator of of the ALT will only allow a certain max amount of current to be pump out, and then it not pump out any more.

Think of an Alt as a battery with a current limit function.
A 70 amp alt will pump out 70 amps and thats it. As I said before if the power required by the electical system is more then the alt. can supply then it will come from the battery. Use of a Cap may help. But most likely the caps in the AMP already has been sized for that AMP.

Please note the cable used to connect the battery to the amp, has resistance in it. So when you current draw goes up, the voltage drop across the cable will go up and the voltage at the amp will fall. Thats why the voltage is going up and down. As I said before, if you are drawing that kind of power all of the time, then you have reduced / lose your hearing.

I agree with the voltage drop being across the line though.

And it doesn't matter how many watts you have. You can lose your hearing by listening to music too loud on headphones.

Yes it is...unfortunately, a lot of the power is wasted as heat. Assuming my class A/B amp is about 60% efficient @ 920W & the class D is 70% @ 1490W, that should be about 265A @ 13.8VDC (which is typically what my charging system seems to like to put out). Of course, this is assuming that I did all my math correctly.

I don't think I'll EVER run the system this high unless I'm at a drive-in & providing bass for people sitting outside the car. Hopefully, I won't be popping fuses because I have a 250A in there right now and since they're $10/each I haven't gotten around to stocking any spares.

Originally posted by Firebat
Actually high current spikes can have problems. If you dont have another battery or a cap right next to your amp power inputs, you will see your volts jump up and down. And probably kill your alternator eventually.
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Originally posted by BruceEmbry

And I disagree, because.
The voltage of the circirt will never fall below the battery voltage. The fact is the requlator of of the ALT will only allow a certain max amount of current to be pump out, and then it not pump out any more.

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Okay so if your alt is supllying about 14v to your batt and you get a current spike you will see a voltage drop across the battery terminals right? Then the reg in your alt. adjusts and for the extra current load and then goes back to normal because it was just a spike. Seems like a chain affect to me. I can't imagine if your having current spikes that it doesn't affect your alt., I don't care how good your alt is.

I just love how this was supposed to be a simple question thread turned into a bunch of wannabe scientifists' lounge. Kwiksilverz28 asked about a certain alternator, not all the technicalities of all the alternators produced in the world today. How this turned into a science fair, well, I'll leave that alone, don't want to be too harsh on people.

And I was speaking of current not voltage. Because it is current that runs though the load that causes voltage to appear on the load. And due to internal resistance of the battery and alt, every thing is in a dyanamic state. We are driving way too deep into this subject. I recommand closure of this topic.

Gentlemen,
Let's please keep this on topic with the original post and not get into a lengthy debate on the principles of physics and electrical engineering.

Thanx!!!!!!!!!!!!!!