Advice for Battery or Alternator

[jdub0802 0]

Hi Nate,

Looking for your solid advice on my current project. I have a SAE-1200D running at 1 ohm, and a MB Quart 4125 running at 4ohms per channel. Stock alternator (105 amp) and a Autocraft titanium battery in my 2004 Impala. The big three have been updated with 1/0 wire, and the alternator has been modded so that it produces about .2 volts more at all times.

With the car warm and music at half level the voltage at the sub amp and the battery is at 14.8 volts steady. With the music at full tilt with heavy bass the voltage drops as low as 12.9 at the battery and amp. This is when it looks like the car is a disco ball and headlights/all the interior lights dim. The voltage drops around from 14.5 to 12.8 on heavy bass notes. The headlights start dimming when the voltage starts dropping into the 13s.

I normally cruise with the volume at 3/4 but like to turn it up when on the highway and the windows are down.

I can only afford to purchase a new battery (thinking D3400) to replace the the front Autocraft, or purchase a new HO Alternator. While I maybe able to add to this later it would be months down the line.

What would be your recommendation to best help the voltage drop right now. I don't plan to add anything more to the system in the future either.

Thank you for your help.

Jimmy

[Nathan@XSPower 47]

Hi Nate,

Looking for your solid advice on my current project. I have a SAE-1200D running at 1 ohm, and a MB Quart 4125 running at 4ohms per channel. Stock alternator (105 amp) and a Autocraft titanium battery in my 2004 Impala. The big three have been updated with 1/0 wire, and the alternator has been modded so that it produces about .2 volts more at all times.

With the car warm and music at half level the voltage at the sub amp and the battery is at 14.8 volts steady. With the music at full tilt with heavy bass the voltage drops as low as 12.9 at the battery and amp. This is when it looks like the car is a disco ball and headlights/all the interior lights dim. The voltage drops around from 14.5 to 12.8 on heavy bass notes. The headlights start dimming when the voltage starts dropping into the 13s.

I normally cruise with the volume at 3/4 but like to turn it up when on the highway and the windows are down.

I can only afford to purchase a new battery (thinking D3400) to replace the the front Autocraft, or purchase a new HO Alternator. While I maybe able to add to this later it would be months down the line.

What would be your recommendation to best help the voltage drop right now. I don't plan to add anything more to the system in the future either.

Thank you for your help.

Jimmy

If you can only change out one of them, then I would go with the alternator, because if the alternator cant keep up your battery voltage is still going to drop some. A 250amp alternator for you application is $499.00 and I would go with a S3400 (same cost as the D3400 but you get posts with the S3400) at $239.00. Prices do not include shipping.

[jdub0802 0]

Thank you for the quick answer.

[j-roadtatts 1,129]

Thanks for clearing that up Nathan. I too agree that an HO alternator is a better first investment over a bigger or dual batterys for a car thats not competing.

[Notorious on mobile 0]

Thanks for clearing that up Nathan. I too agree that an HO alternator is a better first investment over a bigger or dual batterys for a car thats not competing.

That is what I understood. But I see a lot of guys running 2 batts without upgraded alternator.

Why ?

Maybe HO alt are too expensive?

(I'm sure I can't find one for my car).

[Nathan@XSPower 47]

Thanks for clearing that up Nathan. I too agree that an HO alternator is a better first investment over a bigger or dual batterys for a car thats not competing.

That is what I understood. But I see a lot of guys running 2 batts without upgraded alternator.

Why ?

Maybe HO alt are too expensive?

(I'm sure I can't find one for my car).

A lot has to do with the stock alternator. Some stock alternators are 130amps+ but some are only 60amps. If you have a good stock alternator and not a huge system, then adding batteries first makes all the sense in the world. Doing the Big3 and adding a solid battery make a big difference, but if you are putting in a big competition system then the alternator is a good start.

I know a lot of customers that are running 5000watt+ systems and still running their stock alternator with a pretty good battery bank. Just depends on the person and set up.

[jcarter1885 995]

Thanks for clearing that up Nathan. I too agree that an HO alternator is a better first investment over a bigger or dual batterys for a car thats not competing.

That is what I understood. But I see a lot of guys running 2 batts without upgraded alternator.

Why ?

Maybe HO alt are too expensive?

(I'm sure I can't find one for my car).

A lot has to do with the stock alternator. Some stock alternators are 130amps+ but some are only 60amps. If you have a good stock alternator and not a huge system, then adding batteries first makes all the sense in the world. Doing the Big3 and adding a solid battery make a big difference, but if you are putting in a big competition system then the alternator is a good start.

I know a lot of customers that are running 5000watt+ systems and still running their stock alternator with a pretty good battery bank. Just depends on the person and set up.

With that being said I have a question for you Nate. Today I was shopping around for a HO Alternator for my car, I found one which is a good thing. Considering Im not a competitor and will be running a SAZ-2000D (@ 1 ohms) and a highs amp (no more than 700rms), would I need an HO Alt for my application.

Saturn Ion-2003

Big 3 will be done in 3/0 AWG, stock alternator size (105 Valeo Alternator), and I will be purchasing the S3400 and D925 for batteries.

Thanks for the input. What will be the advantage of having an HO Alternator if I do go that route, would I need a HO Alternator with my setup?

[j-roadtatts 1,129]

The reason I personally recommend the HO over bigger or dual batterys "IF" you can afford it. When I installed my D3400 and D1200 in my car with the factory alternator I though it should cure most of the headlight dimming and voltage drop, Well it didn't. After a minute or two of hard playing and the voltage on the dual batterys dropped and could NOT recover until I turned the volumer down and let the factory alt catch up and recharge the batterys.

With that being said, the XS Power batterys are VERY FAST at recovering, which is their claim to fame, So they did do that VERY WELL.

Now the reason a HO is better is, the batterys can only maintain high voltage for a short time before needing recarged, BUT the HO can maintain high voltage continuosly by its self. Which do you think is better?

Now for the math part, If your amplifiers are demanding 2700 watts or 270 amps (amps x 10 = watts) If you have a 270 amp HO alt you in theory don't even need the battery except to start the car. In real time the battery banks are re-inforcement for dymanic peaks.

With all that being said, your amps aren't demanding 2700 watts except at full volume, So realisticly at normal listening levels they are drawing alot less So this is why a stock 130 amp alternator is good enough for most ppl. IS because between the 1300 watts the alt is making, the amplifiers are only using what they need from the battery(s) to fill the void.

A good battery is always important also, and if your factory atlernator is keeping up except for the very occassional peak the your probably are good investing in a few better batterys first.

I think the reason "most" ppl buy batterys is that its usaully cheaper and they can be added as the budget allows, as with the HO alt, its one BIG LUMP all at once.

So my personal advice to you, Jaycee is the same you give every body else, watch your voltage after each upgrade and see what really works.

If you can only afford the battery right now, then thats better than nothing and you will want to upgrade the batterys sooner or later anyways even if you did get the HO first.

If I could go back I would of did the HO first and I bet I would of only needed one good battery under the hood.

BTW I have another vehicle with a Powermaster 200 amp alternator and Warn winch, let me tell you Jaycee, When I installed the HO I experimented with NO batterys and used the winch with the headlights on and they never even change brightness just stayed even kill even with no batterys and turning the winch motor on and off, over and over, VERY IMPRESSIVE.

You must have POWER to make POWER.

[j-roadtatts 1,129]

I wanted to add the reason competors have HUGE banks of batterys is they are trying to get one simotanious BURST OF POWER all at once, not what regular ppl need. Alot of things get carried over to the normal world from competition, but massive battery banks should NOT be one of them. waste of money for the average system.

[jonbearsmt 919]

i would add a cell in the rear... thats just me... then work on getting a alt...

[kirill007 52]

Competitors also use a big battery bank because there are classes where the car should be off.

I would always advise a alt, because that's what makes power, not the batts they only store it.

And most battery's have a floating voltage of around 12.8V or 13V.(some a bit more)

[jcarter1885 995]

I appreciate you guys on your input and it will be taken into consideration, still waiting on your input Nate .

[kirill007 52]

(wtf, i can't edit my posts. hmmm.)

Jay-cee, you have succesfully thread-jacked this thread.

[j-roadtatts 1,129]

I appreciate you guys on your input and it will be taken into consideration, still waiting on your input Nate .

I personally just called him on the phone to discuss my needs, you will get alot farther, alot faster that way. just a thought.

[Nathan@XSPower 47]

I appreciate you guys on your input and it will be taken into consideration, still waiting on your input Nate .

Sorry some how I missed your last question. I would recommend a 200amp or 250amp alternator. That will help meet the needs of your electrical system and help the voltage stay up higher.

[jcarter1885 995]

(wtf, i can't edit my posts. hmmm.)

Jay-cee, you have succesfully thread-jacked this thread.

Oops, my bad .

I appreciate you guys on your input and it will be taken into consideration, still waiting on your input Nate .

I personally just called him on the phone to discuss my needs, you will get alot farther, alot faster that way. just a thought.

I know I just didnt want to bother him with just a simple question, so I could wait since im in no rush.

I appreciate you guys on your input and it will be taken into consideration, still waiting on your input Nate .

Sorry some how I missed your last question. I would recommend a 200amp or 250amp alternator. That will help meet the needs of your electrical system and help the voltage stay up higher.

Your cool, thats why I bumped it just for you. Yeah I talked to DC Power and found out they do have a HO Alt for my car , and its a 275A. Thanks again

Sorry for thread jacking, we can get back to regular scheduled programming.