Big Alternator vs. Second Battery

[Corollacrazy42]

No worries, I know this has been talked about several times but I need to explain my story.

So the other day I was talking with a mechanic I know that was going to test the Highlander Alternator I got awhile back. Never got around to testing it though because he did not have that specific adapter.

Anyways, here is what he told me as a mechanic (and from a friend who usedto be the master tech for Toyota here)

He explained to me that the alternator in these cars is designed specifically for the needs of the car. (this didn't boggle me because 'DUH'). But then he continues to go on saying that, "Since the car only needs 80 amps, that is all it will draw even if a bigger alternator is added"

Now this boggled me and my brother. So we questioned him on this. He now says, "his friend was a master tech for toyota and has heard some horror stories about people frying their computers of their cars." So in return we both say, "well several companies out there make high powered alternators, so whats the deal. They wouldn't make them if they couldn't be used"

Even after our argueing he still stuck to his idea. So now being that I am persuaded pretty easily when someone tells me something directly to my face, I'm kinda scared about even getting a big alternator. The highlander one I put in sucked and seemed to have werid surges of power. he told me that was a pretty good sign that the alternator was not getting accepted into the normal electrical system. I dont know that the electrical systems work like this in a car, but I also know nothing about it.

He was also telling me about ho if it were an older car it would be fine. Saying, "with an older car you can run as big an alternator in your car, because it doesnt have a computer to regulate the amount of power its putting out. He goes on saying that it would be perfectly fine to run a big sound system in this type of car.

Now, while were talking he asks me to pop my hood to look at the alternator I have in it already and what kinda wire and stuff I'm running. He already doesnt like my big 1 gauge wire. Although this is the size my amp requires. Anyways, after this he see's that I have an optima Blue Top. He also doesnt like this, He goes one saying, "You dont want a blue top in here, it has the wrong charging system for this sota thing, you should be running a red top." So now I feel like I have done everything wrong with my car by this point.

Now his solution was for me to buy an isolator and run a second battery to the back. He said my Blue Top would work great as the second battery and then I can just run my stock battery up front again. That's all well and good but, from what I have learned a stock alternator can't charge two batteries. Plus I have a good feeling the Blue Top will die very shortly under that sort of situation.

Now I am pretty confused as to which way to turn.

So now TN I ask you... Is anything this man is saying true? I dont really know what to believe now. I knwo everyone on these cars sites sudjest a big alternator before anything else, so it seems like the smart thing to do. To me it seems that only the pro's that need gob loads of power for a short time run more batteries...

Help me out guys I'm confused...

[Corollacrazy42]

Well apparently I'm not the only one who knows nothing...

[Corollacrazy42]

So no one knows..

[Anshu]

that sounds pretty bogus to me. Ive heard of, been recommended, and have reccomended ppl to put in bigger alternators. I mean all the companies that make them dont supply you a chip aswell that puts the computers to change. Also it doesnt sound like the guy knows anything by commenting on your audio setup.
Do the bigger alt first, the 2nd battery is really only going to help if you like to play it with the car being off alot.

[Corollacrazy42]

He knows audio setup's pretty well surprsingly. But I dont really know anyone that has used a big alternator.

So now also I'll add... If anyone has used a bigger alternator and has seen it in action, let me know as well.

[Delay_FTB]

Check out some audio shop websites and they have installs on there. I know I've seen some with two and three HO alts for systems, especially in large suvs/trucks, and never heard mention of needing to regulate the alternator's supplying of power. And then, since you're audio system essentially bypasses the ECU or anything else anyway, by connecting directly to the battery, it wouldn't matter what the computer said, unless you reprogrammed it to allow for the aftermarket stereo, but that seems like a lot of work. From there, the fuses should protect from power surges and whatnot.

He's right that the car itself will only draw the needed amps, but he must not know electical systems at all. Since the car's electrical system only needs to supply the usual (ac, hu, power anything, starter, etc...) power, thats all the car would consume. Now the audio system is seperate from the car's needs, and has its own power requirements, which is where it bypasses the camputer and feeds itself as it sees fit.

I call bs, also, on the idea that since the car only draws what it needs, then how would the computer "fry"? If the computer knows it only needs 80 amps, then it should draw only 80 amps, and be good. He contradicts himself, unless I'm misunderstanding either him, or my entier (limited) knowledge of a car's electrical system.

I would say that overall, adequate fusing of the wires leading from the alt. should be sufficient protection.

And I must not be able to read correctly, what did he say about your setup?

And no offense to him, but just because he knows mechanical stuff doesn't necessarily make him an electrical expert, even if "his friend was a master tech for toyota"

[Corollacrazy42]

Originally Posted by Delay_FTB

Check out some audio shop websites and they have installs on there. I know I've seen some with two and three HO alts for systems, especially in large suvs/trucks, and never heard mention of needing to regulate the alternator's supplying of power. And then, since you're audio system essentially bypasses the ECU or anything else anyway, by connecting directly to the battery, it wouldn't matter what the computer said, unless you reprogrammed it to allow for the aftermarket stereo, but that seems like a lot of work. From there, the fuses should protect from power surges and whatnot.

He's right that the car itself will only draw the needed amps, but he must not know electical systems at all. Since the car's electrical system only needs to supply the usual (ac, hu, power anything, starter, etc...) power, thats all the car would consume. Now the audio system is seperate from the car's needs, and has its own power requirements, which is where it bypasses the camputer and feeds itself as it sees fit.

I call bs, also, on the idea that since the car only draws what it needs, then how would the computer "fry"? If the computer knows it only needs 80 amps, then it should draw only 80 amps, and be good. He contradicts himself, unless I'm misunderstanding either him, or my entier (limited) knowledge of a car's electrical system.

I would say that overall, adequate fusing of the wires leading from the alt. should be sufficient protection.

And I must not be able to read correctly, what did he say about your setup?

And no offense to him, but just because he knows mechanical stuff doesn't necessarily make him an electrical expert, even if "his friend was a master tech for toyota"

I have seen these two and three alternator applications.. It seems most often though competion guys use more batteries because they want alot of useable power all at once.

I know basically nothing of electrical parts. So anything I learn is something new to me.

But given the first instinct I would say the big alternator would be a better choice then a second battery.. only because im not competeing, and have no care to. I just want a good sounding system I can listen to for along time.

So what are you saying about the fuses though? Run one from the power wire off the alternator to the battery too?

I think I'm definatly gonna stick to the big 3 first of all anyways, because I know that will help.

[Delay_FTB]

Well, I believe that you're supposed to do it anyway, but lots of people don't since they run stock alts. - but when you do the big 3, the wire that goes from your alt. to your batter is supposed to have an in line fuse rated to whatever the alt. is (I think) so that if a power surge from the alt. does happen, it will blow the fuse and protect the rest of the electrical system.

The battery thing is used for when the car/engine is not running, and you're essentially using the reserve power to run things. What you may not be seeing is that under the hood they do indeed have a larger or multiple alternators. A multiple battery setup will need more energy to charge all those batterys, and seeing as how if you completely drained a stock battery, the (stock) alternator would always be playing catchup in order to recharge it. So adding multiple batteries would involve having an alternator that could keep up with the system drain and constantly be refilling/charging the batteries.

If you listen to your system for more than about half an hour with the car in the ACC position, you may need both a bigger alt. and a new batter because with the car off (ACC) the stereo then gets its power from its' battery(ies). Only when the car/engine is on is the alternator running (mechanical energy -> electrical energy) and thus charging the battery and running the electronics.

(I think, anyway... )

[Corollacrazy42]

that sounds right.. cept for the inline fuse on the alternator I dont really understand that. Well I do, but the alternator already has a fuse in the fuse box in the engine compartment. So why would you need another fuse to protect it?

Other than that..sounds right

[JLTD]

The utimate source of all energy needed to move a speaker comes form the alternator. The amp takes the output of the alternator and changes it to something useful to do work. No amount of additional batteries changes this. In fact, the extra battery would actually REDUCE the available voltage to the system because it's an additional load.
A typical car will draw 40 - 60 amps of current to operate no matter how big the alternator is. There are an increasing number of cars on the road in which the voltage regulator is controlled by the computer. In vehicles like this, it's not possible to safely increase the alt output. I don't know if your car has internal regulation or not.
These days it's better to get "loud" with displacement over lots of power.

[inov8]

High-output alternators and local batteries address two different issues. Let's say you have a small building with sprinklers for fire protection. The sprinkler system is fed from a 1.5" pipe that runs to the water main in the street. Now you build an addition to your building, add more sprinkler heads, and discover you cannot flow enough water to maintain adequate water pressure if most of the sprinkler heads turn on. One solution is to increase the pipe size to the water main, which will icrease your flow capacity. This is the hydraulic equivalent of substituting a bigger alternator. An alternate solution is to add an elavated water tank on your property and fill it during periods whan there is no fire. This is the hydraulic equivalent of adding a second battery monuted close to your amplifier.

If you are having a hard time keeping your battery fully charged, then a higher-output alternator is the appropriate solution. If you are having difficulty maintain system voltage level at the amp during loud bass notes, than increasing the wire size to the amp or adding a local battery are the right approaches.

The ECU - apternator link is used by some vehicle manufacturers to delay the response of the alternator in reacting to a step change in load. Particularly with small engines running at idle, turing on the rear window defroster grid, for example, can stall the engine, because the alternator HP requirement suddenly increases. The computer link sends a comand to the alternator telling it, in effect, to at first ignore the load change (let the battery supply all of the defroster current), then react to it gradually. The consequence is a dip in the output voltage. How do I know this? My company designs and builds the "smart regulator" chips that are internal to most modern alternators.

[Delay_FTB]

Originally Posted by JLTD

The utimate source of all energy needed to move a speaker comes form the alternator. The amp takes the output of the alternator and changes it to something useful to do work. No amount of additional batteries changes this. In fact, the extra battery would actually REDUCE the available voltage to the system because it's an additional load.
A typical car will draw 40 - 60 amps of current to operate no matter how big the alternator is. There are an increasing number of cars on the road in which the voltage regulator is controlled by the computer. In vehicles like this, it's not possible to safely increase the alt output. I don't know if your car has internal regulation or not.
These days it's better to get "loud" with displacement over lots of power.

Your statement is for the most part correct, but if that is indeed the case, then you wouldn't be able to run the car's stereo with the engine turned off. When the engine is off, the alternator is not producing current, which is why if you leave a stereo (or your headlights, or dome light, or some other electrical output device) on for extended lengths of time you kill your BATTERY. If things did feed directly from the alternator, and the alternator had the capability to be running while the engine was off, then we really would only need batteries to start the car and for nothing else, and while that is mostly true, the battery also acts as something of a regulator, it seems, protecting the car's electrical system from spikes.

Also, if that were true, then we would hook our stereo amps up directly to the alternator, but we don't. We pull the power from the battery, which pulls from the alt., making the battery a middle man of sorts for powering the car's electrical.

And getting "loud" isn't the issue here, its obtaining adequate power for your stereo/car's electrical system.

[Delay_FTB]

Originally Posted by inov8

High-output alternators and local batteries address two different issues. Let's say you have a small building with sprinklers for fire protection. The sprinkler system is fed from a 1.5" pipe that runs to the water main in the street. Now you build an addition to your building, add more sprinkler heads, and discover you cannot flow enough water to maintain adequate water pressure if most of the sprinkler heads turn on. One solution is to increase the pipe size to the water main, which will icrease your flow capacity. This is the hydraulic equivalent of substituting a bigger alternator. An alternate solution is to add an elavated water tank on your property and fill it during periods whan there is no fire. This is the hydraulic equivalent of adding a second battery monuted close to your amplifier.

If you are having a hard time keeping your battery fully charged, then a higher-output alternator is the appropriate solution. If you are having difficulty maintain system voltage level at the amp during loud bass notes, than increasing the wire size to the amp or adding a local battery are the right approaches.

The ECU - apternator link is used by some vehicle manufacturers to delay the response of the alternator in reacting to a step change in load. Particularly with small engines running at idle, turing on the rear window defroster grid, for example, can stall the engine, because the alternator HP requirement suddenly increases. The computer link sends a comand to the alternator telling it, in effect, to at first ignore the load change (let the battery supply all of the defroster current), then react to it gradually. The consequence is a dip in the output voltage. How do I know this? My company designs and builds the "smart regulator" chips that are internal to most modern alternators.

I like the analogy, but I'm a little confused.

The way I've always understood the water-power analogy is that your piping is essentially the equivalent of your wiring (in terms of gauge) and that the water supply from the street source would be comparable to an alternator (Producing or feeding the water/power). But if your water supply (alternator) isn't sufficient, then your piping doesn't really matter as much.

If that were the case, then the rest of the needed pressure (power) would be obtained from the elevated water source (battery) to temporarily fill the void. Once the water (power) is drained from that source, it then needs to be refilled (recharged), and if the original water source (alternator) wasn't even up to snuff for the original need, then it surely wouldn't be easy to supply that and then expect to refill (recharge) the elevated water source (battery), correct?

I'm not trying to argue here, just trying to clarify, especially since this is always a hot-topic.

And also, if this controller does indeed direct all electrical signals and tells everything what needs to be done, then how would one go about incorporating an aftermarket piece of electronics that needed to be wired outside of the stock wiring system? Or would this be determined by the new equipment?

[Corollacrazy42]

Originally Posted by inov8

High-output alternators and local batteries address two different issues. Let's say you have a small building with sprinklers for fire protection. The sprinkler system is fed from a 1.5" pipe that runs to the water main in the street. Now you build an addition to your building, add more sprinkler heads, and discover you cannot flow enough water to maintain adequate water pressure if most of the sprinkler heads turn on. One solution is to increase the pipe size to the water main, which will icrease your flow capacity. This is the hydraulic equivalent of substituting a bigger alternator. An alternate solution is to add an elavated water tank on your property and fill it during periods whan there is no fire. This is the hydraulic equivalent of adding a second battery monuted close to your amplifier.

If you are having a hard time keeping your battery fully charged, then a higher-output alternator is the appropriate solution. If you are having difficulty maintain system voltage level at the amp during loud bass notes, than increasing the wire size to the amp or adding a local battery are the right approaches.

The ECU - apternator link is used by some vehicle manufacturers to delay the response of the alternator in reacting to a step change in load. Particularly with small engines running at idle, turing on the rear window defroster grid, for example, can stall the engine, because the alternator HP requirement suddenly increases. The computer link sends a comand to the alternator telling it, in effect, to at first ignore the load change (let the battery supply all of the defroster current), then react to it gradually. The consequence is a dip in the output voltage. How do I know this? My company designs and builds the "smart regulator" chips that are internal to most modern alternators.

Hmm thats understandable

So which are you taking side for, or are you saying that either way has its ups and downs. Or suits a situation better as needed?

Anyways, with the second battery wouldnt the alternator have to produce more power to fill and charge both battery constantly. And if that was going on it would leave little room for the the extra things the car uses.

Really though, I dont really have a problem with voltage drop I dont think. It generally stays pretty high I think. The only problem I have really had is some light dimming. It really doesnt bother me, but id rather not ruin that little alternator I have in there if I dont need to.

[Corollacrazy42]

Originally Posted by JLTD

The utimate source of all energy needed to move a speaker comes form the alternator. The amp takes the output of the alternator and changes it to something useful to do work. No amount of additional batteries changes this. In fact, the extra battery would actually REDUCE the available voltage to the system because it's an additional load.
A typical car will draw 40 - 60 amps of current to operate no matter how big the alternator is. There are an increasing number of cars on the road in which the voltage regulator is controlled by the computer. In vehicles like this, it's not possible to safely increase the alt output. I don't know if your car has internal regulation or not.
These days it's better to get "loud" with displacement over lots of power.

So is there anyway I can find out if my car has one of these voltage regulators?

Also why would competition guys use more than one battery if they reduce avaliable voltage.

I believe they use something that allows them to put there voltage upwards of 16-20 volts though. Instead of the 14.4 with your car on.

BTW whats the average voltage range when your car is off? like 13 volts? or just a flat 12?