Hello guys. I am hoping that somebody or even better, multiple somebody's with the knowledge and expertise can help out.
My buddies and I have an argument going about alternators and batteries. The basic question I have been required to ask is..." If you have a car with an alternator and no battery and, another car with both and alternator and a battery and, you also have a totally controlled "so-called perfect world" where no other possible mechanical or technical problem can arise except in the alternator. If both were started and then set free driving as usual with normal wear and tear in this perfect world to see what alternator failed first, which one will fail first?
Will the car with just an alternator last longer or will the car with both alternator and battery last longer in our perfect world?

Can you please explain your answers aswell.
Also if any answers have to due with the resistance of the battery in the field can you explain that aswell.

Also... Does a alternator vary its output of power due to the battery being some sort of resistance in the field?

Also ... If the battery is removed from the vehicle when running will it cause the alternator to surge and create full power, and will this wear your alternator and potentially damage electrical componenets?

Also...Do alternators work differently in modern times as they did 25-30 years ago?( I dont mean single vs triple coil either) I mean the basic all around function?

Also... Can an alternator work at different levels of internal stress that will LEAD TO PREMATURE FAILURE? Will an alternator that produces more power wear quiker that one that produces less?

Thanks alot to all that help/ you are settling a HUGE argument!!!!

 

Well if you have just a alternator and no battery....the alternator will burn out relatively fast from charging full bore nonstop. The alternator with a battery will not charge full capacity all the time if the battery is there to support its work load. Without a battery your headlights will be dimmer. Often one going bad will shorten the life of the other.

 

Mute point, no batt=no start. Sounds like a discussion I may have been in back in the 70's while doing drugs. Sorry, couldn't resist.

 

Why don't you just study some basic theory here:

Alternator - Wikipedia, the free encyclopedia

 

WoW! WTF kinda answers are those? R U KIDDING ME!!! Did you seriously say something about the battery starting the vehicle. Wow your an idiot. You know exactly what I ment. and, If I didnt put it proper i will try again... 2 cars 1 with just an alternator and the other with both alternator and battery. YOU START BOTH CARS!!!! IDONT CARE HOW. JUST START THE THINGS then run them in a controlled perfect world where no other possible failure can occur but the alternator.

As far as theory goes... I UNDERSTAND FULLY!!!! I am trying to settle a 1000$ dollar bet if you must know between two of the guys in the shop. They agreed to settle it by posting in a forum where WE THOUGHT we could find intelligent answers. Except I find some wize azz big mouths quipping about the battery needed to start the vehicle and another joker telling me to learn theory!!! WTF? i UNDERSTAND THE DIFFERENCE BETWEEN A HAND CRANK AND GENERATOR AND STARTER/BATTERY/ALTERNATOR! I ALSO UNDERSTAND THE BATTERY ONCE REACHING FULL CHARGE ACTS AS RESISTANCE IN THE FIELD CONTROLLING THE AMOUNT OF AMP OUTPUT DISTRIBUTED BY THE ALTERNATOR THUS GREATER LOADS WEARS ALTERNATOR FASTER!!!!!!

IT AINT ABOUT ME THO!!!!!! WE ARE TRYING TO SETTLE A BET WITH MULTIPLE INTELLIGENT RESPONSES.

THANKYOU!!!

 

If we go there, in theory the alternator would have less load without a battery, since it doesn't have to charge the battery. A battery is 12v. A alternator is designed to run at approx 13.5-14.5 volts, so it's always putting a little something in the battery. The battery contributes nothing to the vehicle unless the voltage of the system drops to 12v or below.

Also if any answers have to due with the resistance of the battery in the field can you explain that aswell.
I don't know what this means, but the battery and the alternator are two separate entities. The alternator looks at the voltage in the system, and determines what it needs to do from that. The battery is also hooked to the system through the same set of wires, but it's just storage for the next time the car needs to be cranked over. And it does add a little bit of stability to the system, since if the voltage does drop below 12v for some reason, it will start to contribute. It's also a good noise sink for any high frequency noise that may be riding on the 12v system.

Also... Does a alternator vary its output of power due to the battery being some sort of resistance in the field? No. Like I said before, the alternator just looks at the voltage level in the system(in reality the regulator does this, and controls the alternator, if you want to get picky about it).

Also ... If the battery is removed from the vehicle when running will it cause the alternator to surge and create full power, and will this wear your alternator and potentially damage electrical componenets?
It could cause a small surge, because the alternator needs to react to the change in load when you take the battery off. If the battery was really down on charge, and the alternator was working hard to charge it, it could take a split second for it to react and trim back. Now if the regulator was faulty and the alternator is running wide open, the battery will be the only thing trying to hold the system down to a reasonable voltage, and will be boiling in the process. In this case if the battery is disconnected, yes components will be ruined because the faulty alternator will send the voltage sky high.

I have got to go to supper...I'll be back.

 

Also...Do alternators work differently in modern times as they did 25-30 years ago?( I dont mean single vs triple coil either) I mean the basic all around function?
They work the same as the always did, a field winding rotating inside a stationary winding which generates 3 phase alternating current. There have been improvements in the electronic parts of the alternator, and some different physical configurations of each component, but they all still work the same.

Also... Can an alternator work at different levels of internal stress that will LEAD TO PREMATURE FAILURE? Will an alternator that produces more power wear quiker that one that produces less?
I would say yes, an alternator with more load would be more prone to failure and have a shorter life. I say this because;
1. More load creates heat. More power generated in the windings heats the windings, and we all know heat over a period of time will shorten the life of various materials like insulation, and the electronics will be going through more heat cycles, such as the diodes.
2. More load makes the alternator harder to turn. This creates more load on the bearings of the alternator as the belt is trying to turn it. I think we all have had a squealing alternator belt at one time, and know how tight the belt has to be to keep it from squealing right after cranking the engine.

I believe abusing a alternator could lead to premature failure, but obviously the alternator is designed to do a job for a reasonable amount of time before it fails. They all will fail eventually, but I believe the a "babied" alternator would have a longer life.

 

Thats what I am talking about!!! Franklin... YOU ARE THE MAN!!! Intelligent,concise, your post is an example of professional excellence! thank you

Ok.. side point... what I ment by the Battery being a resistor in the field is this.... The battery, when not at full charge, does not provide the resistance to resist the alternator, ( it is not a draw but a passive resistor till fully charged) therefore, the alt charges the bat until full charge then, the amount of resistance is reached in the bat and the alt cant push through the resistance and the alt backs off amp out put due to the regulator sensing this. Thats how I understand it at least. And... if the battery was removed from the field the reg on the alt senses no resistance and cranks the amps out as if the bat was full dead. And the alt has no real mech parts that will fail due to added electrical load... it will be a diode or reg failure or the coil will burn...possibly the fan...

Like i said tho... If these idiots would let me settle it , it would be done. But ,we needed to do this...

I appreciate your time Franklin!!! I hope others with the expertise will jump in... Thanks in advance guys!!!!

 

Srry to double post but, in the interest of personal knowledge and friendly debate I would say this...

Franklin, when you have the vehicle running and you remove the battery from the field why would there only be a short spike in power? whats the difference from the battery removed from the field and a totally dead battery? Does the regulator or PCM decipher the load and resistance variation that would be present with a battery either in or out of the field?

Remember... THIS IS ALL FRIENDLY!!!

 

Friendly? Your response to the other posters in this thread in post #5 was far from that. Name calling, personal attacks and foul language...I'd suggest you read the forum guidelines again (you did read them you registered on the site, didn't you?) And be thankful I didn't issue you an infraction for your inexcusable and uncalled-for outburst. Just because you didn't get exactly the response you wanted is no reason to go off on people like that. Not a good way to start off around here...

 

Applause for the TigerDan!


The way the questions are framed indicate a need for the OP to take a few introductory course in basic electricity / electronics theory.


A selection of them is found here:

http://www.techlearner.com/AZTopTutorials.htm

 

I believe you are getting confused from this "resistance" theory about the battery. The only reason a battery is considered a resistor sometimes, is to explain it's behavior when doing mathematical calculations.

In the real world, the alternator sees the battery as a load, just like it would see the heater fan or any other draw in the vehicle as a load. The alternator is it's own part of the system, and the only thing it looks at is the voltage level of the system, so the only way it can "see" a load is by the voltage drop the load creates. If the battery is down, it pulls the voltage level of the wiring down, and the alternator reacts to this, nothing else. It doesn't see "resistance" it looks at the voltage of the system.

So if you still want to think of the battery as a resistor, then the resistor when placed in the system, would create a load and drop the voltage, and the alternator would react to this. If you disconnected the battery, you would be pulling the resistance out of the system, which would be pulling the load out, and the voltage of the system would rise, and the alternator would "relax" and trim back it's output.

 

A battery is does have what is termed "internal resistance".

Internal resistance - Wikipedia, the free encyclopedia



Internal battery resistance

 

The car with just the ALT will last longer as it has slightly less load and thus lower amp output, which could means less brush wear. In the big picture it is really to close to call and thus you should just cancel the bet. Normal wear is an ALT is just brushes, I don’t think this slight difference in amp output would change normal brush wear pattern.

Also... Does a alternator vary its output of power due to the battery being some sort of resistance in the field?
NO, The battery is not in the field circuit. A small percentage of the ALT power output goes back into the field circuit


Also ... If the battery is removed from the vehicle when running will it cause the alternator to surge and create full power, and will this wear your alternator and potentially damage electrical componenets?
NO, the voltage regulator controls the amp output of the ALT, removing the battery can only cause the ALTs amp output to go down.

Also...Do alternators work differently in modern times as they did 25-30 years ago?( I dont mean single vs triple coil either) I mean the basic all around function?
I have seen more ALT using DELTA windings vs a Y configuration in the stator, delta will produce higher current output. The stator is still just a 3 phase AC output. There have been improvements in the field and voltage regulator circuits.

Also... Can an alternator work at different levels of internal stress that will LEAD TO PREMATURE FAILURE? Will an alternator that produces more power wear quiker that one that produces less?
YES, higher outputs causes higher internal heat. Heat is the biggest enemy of all solid state electrical circuit. Poor heat dissipation is a close second. The G2 ALT bridge rectifier is the best example of poor heat dissipation I can think of, this ALT should only be used at 50% of it rating for constant output, loads (edit.. "over") **** 50% should be of short durations.

So my answers are the same as Franklin2…. Is case you needed further input.

But I do have a question… how can guys working in an automotive shop be able to afford a $1000 bet. Maybe you should charge the customers less.

 

50% is actually pushing it with the loads people are running --- tuners, towing, no cooldown, heat...

You mean loads of over 50% should only be for short durations.


They can afford $1,000 bets, afford to be foul mouthed in making demands on forum members because of what they pay us to answer the questions.