Craziest system on stock ALT!!

[Ed Lester 10+ year member]

Nobody has ever suggested you would need a 694 amp alternator. But you need a bigger one than you apparently think. I guarantee your alt is providing more current to your stereo than 30 amps.

Thats kind of the impression I get when it is said that you cant get energy from nowhere and all the amp's energy needs to come from the alternator since batteries are nothing but extra loads.

Thats how I took it.

 

[Pioneer~Saturn 5,000+ posts]

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[x2o 10+ year member]

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[audioholic 5,000+ posts]

Thats kind of the impression I get when it is said that you cant get energy from nowhere and all the amp's energy needs to come from the alternator since batteries are nothing but extra loads.Thats how I took it.

The alternator DOES provide all the energy (unless you are a competitor running an external charger between burps). The average current draw over time must be less than averaged supply over time, or your finite amount of stored energy in your batts will be depleted at some point. And well before that point you will notice nasty voltage dips.

 

[Ed Lester 10+ year member]

The alternator DOES provide all the energy (unless you are a competitor running an external charger between burps). The average current draw over time must be less than averaged supply over time, or your finite amount of stored energy in your batts will be depleted at some point. And well before that point you will notice nasty voltage dips.

And yes, if I were to play a full tilt sine wave consistantly for a few minutes then my voltage would continue to drop lower than 12v and eventually drop to catastrophic levels.

But I do not burp that long and recharging can happen quick enough to rebound during low periods and breaks in the beats during music.

 

[audioholic 5,000+ posts]

And yes, if I were to play a full tilt sine wave consistantly for a few minutes then my voltage would continue to drop lower than 12v and eventually drop to catastrophic levels.
But I do not burp that long and recharging can happen quick enough to rebound during low periods and breaks in the beats during music.

You say that as if its fact, or a constant, its not. If what you were suggesting were true, nobody who listens to transient material (music) needs to buy a H.O. alt... I mean some people run 100k watts on stock alts right?
It does not take playing strictly sine waves to require a H.O. alt either, nice try. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif I guess this is your way of coming around slowly.

 

[J31Rob 5,000+ posts]

who knows. totally vehicle dependent.

i'm about to see what kinda results i get w/stock alt, red top up front + kinetik 2400 in the read + big 3, and 3,000 wrms.

 

[Ed Lester 10+ year member]

You say that as if its fact, or a constant, its not. If what you were suggesting were true, nobody who listens to transient material (music) needs to buy a H.O. alt... I mean some people run 100k watts on stock alts right?
It does not take playing strictly sine waves to require a H.O. alt either, nice try. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif I guess this is your way of coming around slowly.

You have to look at time.

I have 384 ah of battery storage.

Consuming a max of 916A (measured). for my max measured time of 30 seconds.

So I can theoretically deplete my entire battery storage in about 25 minutes.

So in 30 seconds I am depleting 2% of my reserve.

Are you saying that there is no possible way that a 120A alternator can replenish 2% of my batteries storage?

 

[audioholic 5,000+ posts]

You have to look at time.I have 384 ah of battery storage.

Consuming a max of 916A (measured). for my max measured time of 30 seconds.

So I can theoretically deplete my entire battery storage in about 25 minutes.

So in 30 seconds I am depleting 2% of my reserve.

Are you saying that there is no possible way that a 120A alternator can replenish 2% of my batteries storage?

Lets say that if tomorrow you were to double the number of batts (and therefore, amp-hours) in your system, getting that depletion number down to 1%, does your alt now only have to work half as hard as it did when the drain was 2%? That's what your theory tells us is true. Is it? //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif
Its interesting how this discussion has evolved. Lets look at your original post that brewed up our debate...

I have enough storage for the amount of power I have.
I have explained this so many times recently that my head hurts.

when the car is on, you have a resting voltage of 13.8v to 15v DC (depending on the car. My car rests 14.5v).

When you play your stereo (load starts drawing current) The voltage drops. At this point it will drop to the resting voltage of the batteries. (13v in my case, 12.6v in most cases).

This is when energy is consumed from the batteries.

If voltage drops lower than the resting voltage of the batteries, then the alternator goes to work charging the batteries. The batteries is now what is supplying energy to the amplifiers.

As long as my amplifiers dont draw too much energy from my batteries, then the alternator does not have to work too hard to re-charge them.

All of this works very rapidly, in the matter of milliseconds.

Music is transient and the load is not constant. So my alternator can charge the batteries back up to full and raise running voltage over 14v in the matter of a second during musical play.

Altogether my voltage never drops below 12v DC.

So the alternator never works hard at all.

Because of the low ESR batteries, they charge at about the same rate from 12v to 13v that my OEM batt could charge from 12v to 12.6v.

From this I stated that you misunderstood how/when your alternator starts 'working'. You still do misunderstand, but now want to just start talking about specifics of your system. According to these comments, your 120 amp alt doesn't even start working hard until system voltage drops below battery resting voltage. That is incorrect. Once system voltage reaches battery resting voltage, you are already getting everything out of your alternator that it can provide.
An alternator charges by having a greater voltage than the battery(s). So common sense should be telling you once system voltage equals battery resting voltage, that's it, the alt is giving all it has. Its at this point that battery storage starts to deplete. You think the alt only starts working hard when system voltage dips below batt voltage, because that means the alt is having to charge to batts at that point. You have it all backwards. That's when your charging system starts losing stored/banked energy, going 'into the red' to use a business term, and there must come a time that current demand drops below the potential of the alt (power source) so it can make up those losses. Hence the term 'average over time'.

Cheers.

 

[romans535 10+ year member]

2 RF T1000.1bd- T800.4 - P450.4 and a absolute amp rated at 500wrms. 2 RF T212D2's. 2 sets of 2 sets of 2 RF comps 3 pairs of 6X9's a pair of 4 inch RF comps. all on a stock alt. big 3 and 2 yellow tops. I think I'm kind of border line but unless its real loud I get zero dimming

 

[efm80 10+ year member]

AUDIOHOLIC:

I like alot of your info and as the OP my question is how many watts do you think is practical, safe, and realistic on my stock ALT(110A)???I will upgrade the wiring and either replace my stock battery with 1 good Kinetik battery or just add an extra Kinetik to the back while keeping stock batt. My car is a daily driver and I like to crank it loud, but I would say only 50% of the time. The other 50% is at medium level to low level. Thanks!

eddie

 

[audioholic 5,000+ posts]

AUDIOHOLIC:
I like alot of your info and as the OP my question is how many watts do you think is practical, safe, and realistic on my stock ALT(110A)???I will upgrade the wiring and either replace my stock battery with 1 good Kinetik battery or just add an extra Kinetik to the back while keeping stock batt. My car is a daily driver and I like to crank it loud, but I would say only 50% of the time. The other 50% is at medium level to low level. Thanks!

eddie

Well there are alot of variables to consider. Good job giving your listening habits, most people dont even account for this when talking about charging system needs.
How much of that 110amps does the car use regularly? How bass heavy, and thus power hungry, is the music you listen to? How much of a voltage drop are you willing to accept on a regular basis? Does dimming lights bother you, or do you really not care that much? These are some of the variables I cannot answer, and some of which you probably cant either.

In the end I generally recommend that if its reasonably close to working, try the stock alt first and see what happens. Carry batt cables with you. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif If the system is grossly larger than the charging system should accommodate, only then do I recommend a H.O. right away.

Upgrade big 3 first. Then upgrade your batt if its old or worn. You can also consider adding a rear batt at this point, depending on your exact situation. After you have upgraded these methods, if you still need it, upgrade your alt. But as I said above, if you fork out the coin for some 5kwt amplifier, you should pretty much add the price of a H.O. on to the price tag automatically. Otherwise every time you brag about your 5kwt daily driver system, you are only fooling yourself (to nobody in particular, just saying for example).

 

[snoopdan 5,000+ posts]

I dont know about you all, but my friggn A/C turned on snacks up a bit of voltage on my setup //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

 

[efm80 10+ year member]

Well there are alot of variables to consider. Good job giving your listening habits, most people dont even account for this when talking about charging system needs.
How much of that 110amps does the car use regularly? How bass heavy, and thus power hungry, is the music you listen to? How much of a voltage drop are you willing to accept on a regular basis? Does dimming lights bother you, or do you really not care that much? These are some of the variables I cannot answer, and some of which you probably cant either.

In the end I generally recommend that if its reasonably close to working, try the stock alt first and see what happens. Carry batt cables with you. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif If the system is grossly larger than the charging system should accommodate, only then do I recommend a H.O. right away.

Upgrade big 3 first. Then upgrade your batt if its old or worn. You can also consider adding a rear batt at this point, depending on your exact situation. After you have upgraded these methods, if you still need it, upgrade your alt. But as I said above, if you fork out the coin for some 5kwt amplifier, you should pretty much add the price of a H.O. on to the price tag automatically. Otherwise every time you brag about your 5kwt daily driver system, you are only fooling yourself (to nobody in particular, just saying for example).

great answer! thanks. I want to have about a 1600-1800 watt sound system. Dimming lights really do not bother me and I really do not listen to rap which is probably the most bass heavy. Voltage drops probably wouldn't bother me too much cause I really wouldn't know, hehe! I am by no means going to compete or do regular metering. With that being said I have a 2008 Honda Accord EX 2.4L 4cyc. I had an 1120 watt system on my old 2002 Accord for 3 years with no upgrades whatsoever except a 1.0F capacitor with no real issues except dimming lights at high volume. I want to upgrade now and the problem is I would buy a H.O. Alt no problem but they do not make one for my car //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif So I was gonna upgrade battery and Big 3 and was hoping I would be fine... what do you think AUDIOHOLIC?? thanks!

eddie

 

[Kicker Guy 10+ year member]

Wow the answers here amaze me, I was never able to hold crap for voltage with a zx2500 zx650.4 and a zx200.2 with a stock 105 amp alternator and a kinetik 800 and 2400. Guess I don't have enough fairy dust... can I borrow some?