Second battery or higher output alternator ?

 

New member
Username: Reinkor

Post Number: 1
Registered: Feb-06
I have 1 kicker 400watts amp and I'm planning to get a 2nd, but when the car is on idle, the intensity of my lights drop a bit and i can see my volt guage freaking out , the needle is boucing from right to left..
I was wondering if it was better to simply change my stock alternator (130 amps) for a 200 amps, or add a secondary battery?
oh and I have a 1F cap.
 

Silver Member
Username: Fandim

Reno, Nevada United State...

Post Number: 757
Registered: Jun-05
alternator, always upgrade the heart before you upgrade anything else.
 

New member
Username: Reinkor

Post Number: 2
Registered: Feb-06
ok thank you
 

Silver Member
Username: N2audio

Lawrence, Ks USA

Post Number: 669
Registered: Mar-04
I'd double check your amp's installation - every connection - ground - make sure all fuses are intact etc.

There's absolutely no way a 130A alt should even flinch with a 400w amp. There's a problem somewhere.
 

Silver Member
Username: N2audio

Lawrence, Ks USA

Post Number: 670
Registered: Mar-04
I would also take the cap out just to eliminate that as a problem until you can figure out what's going on.

I've got about 1200w with a 110A alt and it runs fine - dimming is almost unnoticable at full volume.
 

Silver Member
Username: Fandim

Reno, Nevada United State...

Post Number: 761
Registered: Jun-05
Optidriven - if his stock alt is 130 amps, maybe his vehicle (which he dosnt specify) uses nearly all of that, leaving very little left over for a 400w amp.

The fact that you use a 110 amp alternator, and a 1200 watt amp, and preach about how great the opti lines are...leaves me questioning how much wattage your amp really produces..
 

New member
Username: Reinkor

Post Number: 3
Registered: Feb-06
oh, its a mustang gt 1997
 

Platinum Member
Username: Glasswolf

Wisteria, Lane USA

Post Number: 11210
Registered: Dec-03
a 1200 watt class-D amp can draw up to 120A of current, in addition to the 50-60A or so your car will draw for it's own systems.

a 1200 watt amp is rated with a non inductive load though, and a tone generator at full output.
Music being dynamic, and speakers being reactive, I doubt he really uses more than 800 watts of that power though, if that.
 

New member
Username: Eater

Post Number: 3
Registered: Feb-06
if you have a deep cycle battery u dont need a ho alt
 

Platinum Member
Username: Glasswolf

Wisteria, Lane USA

Post Number: 11225
Registered: Dec-03
whatever you say.
 

Silver Member
Username: N2audio

Lawrence, Ks USA

Post Number: 673
Registered: Mar-04
Optidriven - if his stock alt is 130 amps, maybe his vehicle (which he dosnt specify) uses nearly all of that, leaving very little left over for a 400w amp."

and maybe monkeys will fly out of your a $ $

"The fact that you use a 110 amp alternator, and a 1200 watt amp, and preach about how great the opti lines are...leaves me questioning how much wattage your amp really produces.."

The fact that you criticize me for stating that which is known by hundreds of Optidrive users leaves me knowing you're full of yourself.

I tend not to reply unless I have something worth saying.

You may find be interested in knowing my 2 Optidrives happen to be '03 (Zed Audio) models that I'm sure - in your expansive knowledge - you are well aware are stiffly regulated amps.
They produce rated power at anything above 11v, and typically about 25% more than rated power at 14v.
My 100.4 runs at 4 ohms bridged (180x2 rated) and my 1000.1D runs at 2 ohms (700w rated). If that doesn't equate to around 1200w - please feel free to correct me.

Regarding the Mustang's 130A alternator...Automotive engineers - believe it or not - are intelligent enough to recognize that electromechanical devices do not tend to live long happy lives when they're continually, or frequently operated near their limitations. It is also known that a major goal of any mfg is to ensure the vehicle will operate relatively free of failures until, at a minimum, the warranty expires.
If you ask around, any truly competent mechanic or automotive electrician will tell you stock alternators almost always provide some degree of headroom when it comes to current output. Obviously the amount of headroom would vary, but 40% is the number I've heard more than once. If this were not the case, we'd see the streets littered with stranded cars because of dead batteries. I'm sure marc isn't the only person running a 400, 500 or 1000+ amp on their stock electrical system. Come to think of it, one of the moderators at sounddomain runs 1.9+kw on the stock charging system of his saturn, which has a 95A alternator. The only mod he's done is the big 3. It's been running successfully for 7 years. That is obviously an extreme case, but I'll assume you get the point.
I can say with much certainty there's no WAY that alt should have any problem at all with that amp - or two of them for that matter. At 3, I'd expect to see a little dimming, still no major problems. The 3G is a STRONG alternator, and the stock electrical demand of a '97 Mustang is no more than average.


 

Silver Member
Username: N2audio

Lawrence, Ks USA

Post Number: 674
Registered: Mar-04
"find be interested"...
beautiful Upload
 

Silver Member
Username: Safe_cracker

Chicago, IL US

Post Number: 299
Registered: Jan-06
Hey Opti, you sure your putting out 1200W? I have a 2001 Pontiac GrandPrix GTP (full power) and it has a 110A alt and with my Kicker SX1250.1 I can almost use my alt as a brake! LOL. I get a lot of dimming especially with Mke Jones or 3-6. I am not doubting you or anything just trying to compare (so relax :-) ) Polo..


PS- Anyone capable of making a 300A alt fit my car let me know... :-O
 

Platinum Member
Username: Glasswolf

Wisteria, Lane USA

Post Number: 11239
Registered: Dec-03
he does have a point there. look at a durango for example. fully loaded models have a 165A alternator stock, and the SUV uses most of it for power heated seats, HVAC, stock premium audio, tow winch, lights, engine, etc.. cars don't come with big alternators just for fun.. it isn't cost effective to the car maker.. only exception to that I can think of are police packages since the alternator is there to handle the lights and sirens.
 

Gold Member
Username: Carguy

Post Number: 5340
Registered: Nov-04
My Acura came with 75A stock alternator. With lights (20A), heated seats(20A), heater(15A), radio (10A), left me with just about nothing for stereo amps.
The size of "stock" alternator can be very deceiving cause by the time you add up all the devices in the car, you'll end up with 10A-20A left for accessories.
 

Silver Member
Username: N2audio

Lawrence, Ks USA

Post Number: 677
Registered: Mar-04
"Hey Opti, you sure your putting out 1200W?"
No, but if not, it's awfully close.
My amps are under-rated. Going by ratings I'm running 1060. My comp amp is 180x2, tested at 200x2 resistive, 253x2 reactive, 14v. My sub amp is 1000x1 at 1 ohm, 700 at 2. Some tests have it as high as 1300+w at 1, so at 2 ohms I'm conservatively guessing ~800w.

I've seen severe electrical problems as well when the current demand of the amp and the electrical system seemed to match up fine. Every case was improved drastically by making changes to the amp's wiring. Sometimes it's just one connection - sometimes it takes an entire re-installation.

It would be sad if we send marc off for an HO alt to run a 400w amp. It is completely obvious there is another issue here, and I couldn't be more surprised that I'm getting resistance on that opinion.
 

Platinum Member
Username: Glasswolf

Wisteria, Lane USA

Post Number: 11255
Registered: Dec-03
perhaps for a 400 watt amp but he said he's adding a second big class D amp, and that's usually a quick path to a better charging system.
 

Gold Member
Username: Carguy

Post Number: 5345
Registered: Nov-04
I say better safe than sorry. Besides, with HO alternator, he can add extras like, power inverter, 300w spot lights, heated windshield spray, 120w AM radio, neon light kits etc.
 

Silver Member
Username: Safe_cracker

Chicago, IL US

Post Number: 301
Registered: Jan-06
I put some Young Jeeze on today (daytime) and cranked her up till I started to smell coil glue then backed it down a hair. I love these Re subs, well my voltage read 12.8 at the min so I guess full bore at night will be out of the question until I get a better alt. Anyone have any pictures of custom mounted alts? I have a transverse mounted engine and I need to find a 300A alt, so far I have been shot down by everybody. Polo.
 

Silver Member
Username: Fandim

Reno, Nevada United State...

Post Number: 772
Registered: Jun-05
Glasswolf/Isaac, thanks for posting that a vehicles stock alt can be almost entirely used up by the vehicle after lights/etc.

----------------------------


quote:

Optidriven - if his stock alt is 130 amps, maybe his vehicle (which he dosnt specify) uses nearly all of that, leaving very little left over for a 400w amp."

and maybe monkeys will fly out of your a $ $




That made me chuckle.

----------------------

Also - Optidriven, a 400 watt, class AB amp (at 65% efficiency) can use around 51 amps. That can easily push a cars load to the point where it's over what the alternator can produce.

I'm not personally attacking you, just stating the fact that since at peak levels, putting out 1200 watts at 80% efficiency could use 125 amps - and you have a 110 amp alternator... The math just dosnt add up very well in my head. Do you not crank the volume often? Or listen to bass light music, etc? Even at 66%, like in glasswolfs example, putting out 800 watts (since music is - agreeably - dynamic, and not a test tone), that would still be more than 80 amps of pull, and assuming your car used only half of the power the alternator can produce (doubtful), that would still leave you with 135 amps of pull.. And you notice no voltage dip or your lights dimming?

Like I said - I'm not personally attacking you, just not seeing how your amps really put out the amount of power they claim, yet you're fine with your current charging system.
 

Silver Member
Username: N2audio

Lawrence, Ks USA

Post Number: 691
Registered: Mar-04
The math adds up just fine if you have any understanding at all of the crest factor of music. That's my entire point. It always has been. It will continue to be.

As I often recommend - you all should try browsing a couple other forums and see all the hundreds (thousands?) of people out there running 1000w+ systems off stock 70, 80, 100A alts with a minimum of concerns.

Yes, there are those with problems, and more times than not, a good re-installation solves them.

I know this forum bows down to GW in every way, which is fine, he's obviously got some knowledge, and I know he knows what crest factor is too. Unfortunately, for some reason he's left that out enough times that this forum has come to the conclusion that an amp's maximum possible bench test current draw has anything to do with its real world MUSIC current draw.

Sure, my lights dim a bit when I blast it. It's slight, it doesn't bother me, if I wasn't specifically watching for it I wouldn't notice it, and it certainly doesn't bother other drivers.

When I had a slightly less powerful system (~900w) with my old 75A alt, it dimmed a little more noticably, but my battery retained its charge, which, when it comes down to it, is all that really matters.
 

Gold Member
Username: Carguy

Post Number: 5363
Registered: Nov-04
Optidriven, I think GW and quite a few already know what Crest factor is. Yes they do make sense in theory.
However, not all cars are made the same, just like amps. Just as opinions differ amongst installers, I like to be on the "safe" side. The way I view it is, it's never a good idea to draw more current than what the alternator can produce. Like all electronics, pushing anything to the limit, usually shortens their life cycle.
With my installs, 12.5v is the limit. Anything below that, the starter battery is in jeopardy. There won't be enough current left to recharge.
I've seen and heard too many people with dead alternators/batteries.

Using dimming lights to determine power problem is not accurate and meaningless.
Proper way is to measure the voltage on the battery (12.65v) and the alternator (14.9v). Then take the amp that will be used, and determine the average and max current draw (actual test with digital current and voltage monitor, not mathematically formula). This will insure the amp will get the proper power needed to perform.
The final step involves monitoring of voltages at near max volume level after the installation.
Optidriven, I really don't have problems with your posts/recommendations, however, I hope you will put a little caution in the mix. Not all readers are educated in electronics.
 

Silver Member
Username: Fandim

Reno, Nevada United State...

Post Number: 773
Registered: Jun-05
Optidriven, I'm aware of what crest factor is. However, 'dynamic' music isnt exactly the best way to describe a lot of todays rap songs, with long, repeating notes in the 30-60 hZ frequency. And that's what a lot of people are looking to play, and 'bump' in their cars.

If I'm playing music that I actually like (old metallica, pantera, led zep, black sabbath) I have no problems at all with my voltage.. (all my amps combined are at a little over 3k rms) with a 200 amp alternator.

However, I think 'crest factor', (FOR THE MOST PART) goes out the window, when playing songs like "Late Night Tip", any bass track, or even a lot of other popular rap songs.

For instance, with a fully charged trio of yellow tops, and a 200 amp alternator, playing metal type music, my voltage goes from about 14.8 (on a digital meter) down to 13.9 - 14.5, normally closer to the latter, during highway driving where my alternator is constantly at full bore.

Playing rap songs, it very slowly starts dipping.. 14.5, 13.9, 13.4, 13.0, 12.8 etc., and will actually start taking it lower than 12 volts, given enough time. (Which is when I switch CD's, turn the volume down, or just turn it flat off..) And in this scenario, takes a bit for my voltage to even return to 14.4+, if I let it drop below 12.)

Seth
 

Gold Member
Username: B101

Queen City, NC USA

Post Number: 1406
Registered: Sep-05
"As I often recommend - you all should try browsing a couple other forums and see all the hundreds (thousands?) of people out there running 1000w+ systems off stock 70, 80, 100A alts with a minimum of concerns. "

my stock had a 105a alternator factory. It couldnt keep up with itself!!! NO SYSTEM! Digital climate control will suck that badboy down to 12volts!!!

When I had my 500rms it would make my lights dim!! factory alternator!

200a alternator, 2 batteries, big3 4&0ga I can still make my voltage dance a little bit @ idle.
That was with my old memphis prd1000.1 ! & a 200.2...
I noticed the 200.2 used considerable amt of current(AB), so I kept that turned down less than half!

I cant see 80a pushing a 1000d to full power..
I noticed significant diffrence, with the output of my 1000d from 105a to 200a.

The whole thing here, is that I think my chargin system is better than others; far from factory, far from best! but I cant see anyway around not getting a HO alternator! Just from my experience & habbits!

I think Seth likes it LOUD and so do myself! I like to have my system almost full tilt @ idle... some people have diffrent prefrences.. lol
When im driving its just too much too take... lamo!

I listen to Rap/Reggae I like low beats, thats all I listen too... It will make your system drain!! trust me!
 

Platinum Member
Username: Glasswolf

Wisteria, Lane USA

Post Number: 11284
Registered: Dec-03
I've mentioned numerous times in postings that music is dynamic, and most people don't run amps at full volume both of which reduce the power requirements substantially.
I've also noted that double the volume means six to ten times the power consumption from the amps, and that "1200 watts RMS" means a non inductive load (speakers being reactive) at impending clipped signal at full output with a signal generator.. that pretty much means the absolute most power the amp can put out continuously, which isn't ever going to happen in a car.

However, all of that being said, I also suggest alternators capable of sustaining that if at all possible, because of a number of reasons.. people are always upgrading amps and systems, and I don't want to suggest half the alternator they need only later to hear, "You told me it was enough!"
So yes, I go overboard, but I know it'll always be enough. I over-engineer so I never get caught with my proverbial pants down later.
 

Silver Member
Username: Fandim

Reno, Nevada United State...

Post Number: 775
Registered: Jun-05
Heh... In my case, even with the impedance rising with heat.. I'm putting out the same amount of power (or close to it) since the amps i'm using put out the same from 1-4 ohms.. (And I sure hope I'm not going from a 1.5 ohm load, to a 4 ohm load on a single voice coil of a dvc sub.. (one amp on each vc)).

Glasswolf, curious, wouldnt most people pushing their amps to clip be considered their amp drawing 100% of it's rated power? (assuming the voice coils wernt hot at this point, for example first thing in the morning, etc..and the clipping was due to inproper gain, not lack of available power.)
 

Platinum Member
Username: Glasswolf

Wisteria, Lane USA

Post Number: 11293
Registered: Dec-03
not always. a clipped signal can be caused by a number of factors, some of which can clip the signal before it even reaches the amp's inputs.
 

Silver Member
Username: Fandim

Reno, Nevada United State...

Post Number: 777
Registered: Jun-05
That's why I specified the inproper gain in my second question.. Setting the gain too high, forcing clipping from the amp, dosnt this then assume your amp is being pushed to it's max? And I'd bet at least 1/3 people on this forum clip the hell out of their amps, heh..
 

Silver Member
Username: Safe_cracker

Chicago, IL US

Post Number: 316
Registered: Jan-06
The music itself, especially if downloaded P2P can contain clipping in itself. Your head unit on any given song can cause clipping. I am actually learning this that is why I am investing in a nice tech oscilloscope. I run my music through an audio program called Audacity which will detect clipping in a particular song and offers corrections for it. You can also "BOOST" those low sounding songs in any or all of the frequency range and do so with a clip detection to make sure you don't go to high. You gotta love this hobby, lol...Polo. :-O
 

Platinum Member
Username: Glasswolf

Wisteria, Lane USA

Post Number: 11311
Registered: Dec-03
Seth no. It means the *input stage* of the amp is clipping, which results in the "unamplified" signal squaring off, and being amplified as a square or clipped wave.. so you can clip without clipping at full output.

make sense?

garbage in = garbage out
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