# help on increasing my voltage!!!



## chrisb33 (May 13, 2010)

is there a thread that can help me on how to increase the voltage output of my electrical system? i did the search but nothing on specific how to's. anyway, here's my dilemma that has been going on for 3 years now. over the years ive been trying to diagnose and solve the problem as budget and time permits. but now im running out of ideas and im sooooo frustrated already:

im running an audison lrx 6.9 and an audison srx1 mono amp which i only use for SQ. plus the wattage of these amps are considered low vs. other powerful amps so i doubt that my sound system is the one causing my low voltage.

upon cold start my turbo timer voltage reader says 14v. but that only lasts til the car gets warm. when the engine is warm the average voltage reading i get is 13.2 - 13.6v. sometimes when im driving it goes as low as 13.00. engine off, no load, voltage reading is at 11.6-11.8 volts. it should read at least 12 right?

when on full load (head lights, stereo, and AC is turned on) system is at 13.0-13.2v. when i use the turn signal, voltage drops around .01 per click of the turn signal. When i step on the brakes...i assume this is because of brake lights, i get a massive drop to sometimes 12.8v but goes back up again to 13+ when i release the brakes.

now this is where it gets more weird. when i rev the engine, the voltage drops rather than go high! i doubt i have alternator belt slippage coz i could hear that right?

i only have one battery which is relocated at the trunk because because it wont fit in my engine bay anymore plus, it protects the battery from heat.

my turbo timer and my head unit reads the same same voltage reading. when i have my batteries checked, that instrument that they connect directly to the battery to check the voltage also reads the same thing. +/- 0.1 - 0.2 volts.

i've tried almost everything already to get me to at least 14.2 volts. i'm aiming for 14.4:

1. changed new battery
2. increased the ampere rating of my alternator to 120 amps.
3. 5 point grounding
4. big 3 (using just gauge 4 wires though)

here's what i plan to do in the next couple of weeks:

1. have my damn alternator and its internal voltage regulator checked.
2. check the tension on my alternator belt (should be done later)
3. change my five point grounding wires to hks. i have this already to replace my generic ones. plus my grounding kit is 6 years old already. and has endured flood! so might as well.
4. only as a last resort...upgrade my big 3 wires from gauge 4 to gauge 0/1. sine my main battery is at the trunk, this will be kinda expensive coz of the length of the wire/s needed.

is there anything else i should take a look at? am i missing something?

im so frustrated already!!! please help me!!!!

thanks!!!

chris b


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## TREETOP (Feb 11, 2009)

Your battery is quite a ways away from your alternator, what size is the wire between them?


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## Oliver (Jun 25, 2007)

I'd take it to a shop , where trained ... experienced people can show you a before an after.

You've tried everything you can think of.

http://www.bcae1.com/charging.htm

http://www.familycar.com/classroom/charging.htm


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## Guy (Feb 16, 2006)

What are you looking to accomplish or improve with higher voltage? There are units available to raise voltage to your amps, but because your amps have regulated power supplies there won't be a benefit.
Considering the distance between the alternator and battery, your voltage looks good.


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## chrisb33 (May 13, 2010)

TREETOP said:


> Your battery is quite a ways away from your alternator, what size is the wire between them?


im using gauge 8.

chris b


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## chrisb33 (May 13, 2010)

Guy said:


> What are you looking to accomplish or improve with higher voltage? There are units available to raise voltage to your amps, but because your amps have regulated power supplies there won't be a benefit.
> Considering the distance between the alternator and battery, your voltage looks good.


well just because the normal system voltage of a vehicle should be at around 14.4v right? wont this affect power output of the amps and the head unit?

chris b


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## Oliver (Jun 25, 2007)

Yes it will , power in affects power out , it is usually expressed in a ratio.

Adjustable voltage regulator will give you more voltage...

A smaller pulley on an alternator will allow for more voltage at idle..

2 - 8 volt batteries in series will equal 16 volts...

What are you trying to do ? SPL competitor ?

Kidding yourself that your soundsystem is not dragging down your voltage?


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## chrisb33 (May 13, 2010)

Oliver said:


> Yes it will , power in affects power out , it is usually expressed in a ratio.
> 
> Adjustable voltage regulator will give you more voltage...
> 
> ...


hi, 

no. im just into sq. but even when my sound system is turned off i get the same voltage reading. so i really doubt if the sound system is the culprit. 

chris b


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## yotacoma (Aug 22, 2009)

chrisb33 said:


> im using gauge 8.
> 
> chris b


might be part of the problem, try uping that to 0ga and all of your big3 to 0ga


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## TREETOP (Feb 11, 2009)

chrisb33 said:


> im using gauge 8.
> 
> chris b


MarkZ may disagree with me, but my opinion is that 8ga is WAY too small for a charging wire, especially at that distance. There's probably enough voltage drop in that wire alone to cause your entire issue.

I'm assuming your vehicle's electronics are still connected up front, so they're also running off a very long length of 8ga from the battery. I don't know how your alternator/battery/electronics junction is done, but I'd seriously consider changing that little charging wire to _at least_ a 2ga.


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## chrisb33 (May 13, 2010)

yotacoma said:


> might be part of the problem, try uping that to 0ga and all of your big3 to 0ga


yeah i just might do that. it will cost me an arm an a leg though. sigh.

chris b


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## chrisb33 (May 13, 2010)

cajunner said:


> what are you trying to prove?
> 
> remember, if you're into sound quality, use amps that have good power supplies.
> 
> ...


dude take it easy. im not trying to prove anything. im just here to ask for help on my dilemma that has going for years now. 

chris b


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## chrisb33 (May 13, 2010)

cajunner said:


> let me say that it's your computer changing the charging requirements as you drive down the road, using known pre-sets and is the cause for your voltage changes.
> 
> also, if you're running 8 gauge wire from the alternator to the battery as a charging wire, then you've isolated a big part of the problem.
> 
> ...


yeah maybe that gauge 8 is giving me a problem. will try to upgrade it within the week and then fuse it too. 

so voltage reading after warm up shouldnt be constant at 14.4 volts? should i be happy getting just 13.6 volts on a regular basis?

chris b


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## kyheng (Jan 31, 2007)

Asian cars won't give you 14.4V most of the time. You are getting 13-13.6V which is normal. Maybe you need to check your connections. Or are you thinking that there's such thing of 0 resistance?
When you press your brakes, you are not pressing your pedal which will cause some RPM drop, which is again normal.
Maybe is good that you check back your alternator's spec, when it will give 100%, 75%, 50%. As long as it is giving output of >13.5V(or higher than battery), it is ok. Alternator is used to charge your battery after it supply to everything on your car.

Or are you just want to see "bigger" watt on 14.4V? That's pointless. If the watt were to measured on bench, it can give more misleading numbers. because the AC-DC convertor can give a more steady load compare to alternator.


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## RBeachTL (Jul 21, 2008)

I agree with Yota' and Treetop, your small gauge wire is most likely causing your voltage drop. Go to the bottom of this webpage:

American Wire Gauge table and AWG Electrical Current Load Limits with skin depth frequencies

and use the voltage drop calculator. See if it explains what you are seeing. Then see what happens when you upgrade to larger gauge wire. In fact this is a great example of why larger gauge wire is advantageous; preventing too much voltage drop.


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## dougelam (Apr 24, 2009)

It is nice that people are trying to help you but you did not give all the information needed to make a proper diagnosis. If you are using the voltmeter in the car as you stated it is not accurate, you need to use a separate voltmeter to determine what the voltage is and an amp meter to determine what the current is. Your battery voltage should be 12.6v sitting on the bench, not 12.0v. This is very important to you if you are worried about 13.6v or 14.2v, that could be the difference that you are looking for and using the wrong meter could be your only problem. Your battery is the only voltage source, it regulates the voltage output from the alternator and the demand from your car regulates the amperage output from your alternator. As the demand goes up so does the amperage, the voltage stays pretty close to the same as you zoom down the road unless the amperage draw goes to high and the voltage raises the output voltage to offset the lack of more amperage. What ever your voltage regulator is set at is what it will be for the duration of its life. That is why most power amps like yours have a regulated power supply so they don’t upset the vehicles charging system. You need to explain better where your battery positive wire is hooked up to at each end and same with your ground wire. Where is your alternator wire hooked up at, each end as well. As treetop stated, where is your system hooked up at, again power and grounds. An 8g wire is ok for charging alone, but if your system is on that same line it would need to be upgraded. Grounds are very important, yet easily overlooked.

The last line is correct, the rest is stupid logic
top off and maintenance are variable state loads that changed

(There are usually 3 different charging states that an alternator can be in, one is to "top off" the drain of intially starting the motor (14.4V, usually coming down in the first few minutes), another is the running voltage after "topping off" is done with, also called the maintenance voltage (13.2V), and the last is the variable state that changes with load.)

And yes, you need to have a garage check you charging system. A starter/alternator shop would be your better choice as that is what they do


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## MarkZ (Dec 5, 2005)

"upon cold start my turbo timer voltage reader says 14v. but that only lasts til the car gets warm. when the engine is warm the average voltage reading i get is 13.2 - 13.6v. sometimes when im driving it goes as low as 13.00. engine off, no load, voltage reading is at 11.6-11.8 volts."

^^^^

This makes it very unlikely that the wire size is the problem.

Also, somebody explain to me how 8ga wire could cause the following symptom:

"now this is where it gets more weird. when i rev the engine, the voltage drops rather than go high."

Do you guys read, or what? 

Obviously we need more info to properly diagnose the problem, but it sounds to me like an alternator failure or funky regulator issue.


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## RBeachTL (Jul 21, 2008)

I agree that we don't have enough information to do a complete diagnosis but do you think that a failing or defective alternator would continue for 3 years? It would be nice to know how the wiring for the battery relocation was done.

Do you know that voltage drop is proportional to current draw?

Did you read that the battery and alternator have either been changed or upgraded?


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## MarkZ (Dec 5, 2005)

You're right, voltage drop is proportional to current draw. But his observations seem to be independent of current draw. If I understand his description correctly, system voltage is dependent on engine RPM, but in the wrong direction. Also, the "engine getting warm" affects the voltage substantially. These aren't voltage drop across a wire issues. This is a case where the alternator is simply not behaving in a predictable way.

Sure, it's POSSIBLE that this could be the outcome of a really pukey connection somewhere, or a resistive short, or something along those lines. But that's NOT an 8ga wire issue.

Until we get more information, my money's on either a mechanical issue or a faulty component -- alternator, battery (less likely), or some sort of ECM thing.


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## chrisb33 (May 13, 2010)

hi, i will try to be more detailed on how my cables are connected and to clarify some symptoms:

1. when i rev, the voltage drops at around 0.2 - 0.4 volts but not linear. it just drops by that much regardless of what rpm i am at. like 13.6 at idle, and then 13.4 when im driving. sometimes it goes back to 13.6 and drops back to 13.4 again without letting of the gas.

2. main cable is terminated from stock termination point from the engine compartment to the positive terminal of battery located at the trunk using one long cable. grounding is shorter with just one cable also terminating from battery to trunk chasis. i just double checked my big three cables and it seems like they're gauge zero after all. i remember using a gauge zero welding cable a few years back when i relocated the battery. but my charge wire to the alternator is still gauge 8. 

3. size 8 gauge cables for 5 point grounding as follows: 
a. to firewall
b. to cylinder head
c. to fuel rail
d. to transmission
e. to engine chasis

4. size 8 gauge from stock termination point from engine compartment to alternator. 

il visit my local alternator/electrical shop within the week to have my alternator its IC checked. then re-do my grounding and then change the gauge 8 wire to the alternator to either gauge 4 or gauge 0. 

yes the battery has just been replaced just a few days ago. the alternator has been upgraded to 120 amperes with IC voltage regulator 3 years ago. the last time i had my alternator serviced was a year ago where they had to change the carbon brush due to wear and tear and also because it was flooded. 

sadly i dont own a stand alone volt meter nor do i own an amp meter so i wouldnt be able to check that until i visit my local shop which has the tools. 

damn, so at no load and engine off, the volt reading should be at 12.6 volts? id be happy to get anywhere near that. 

so if i can get my voltage stable between 13.6 to 14.0 i should be worry free already? is this on full load? or just engine on, AC, and HU on? coz as of the moment, what i get when on full load is around 13.0 - 13.2 volts. again is this normal voltage when on full load? 

i will try to take some pics once i get to borrow a digital camera. so that you guys can see how my cables are terminated. 

thanks so much for your inputs. keep 'em coming! you guys are the best 

chris b


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## kyheng (Jan 31, 2007)

Remove the voltage regulator or reset the settings may help.
Your battery should be above 12V usually, not really must see 12.6V. Different brand got different voltage, but is >12V. As long as it can provide you enough current for starting your car, you will be good. My battery only give me 12.2V from day 1 I bought and after 3 years it is still standing strong.
Some cheapo multimeter from China are more than enough, or if you have a lot of money to spend, Fluke is a good brand.


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## TREETOP (Feb 11, 2009)

MarkZ, think of it this way- 
Let's estimate the length of the charge wire at 17' long. 
All engine/electronics connections are up front, just the battery (and likely the audio) connected in back.
Thinking of the battery as a buffer for the electrical system, anything needed over the alternator's output is drawn from the battery. Well, the battery never gets a full charge because it's being drawn from up front while the alternator is trying to recharge it, power is obviously having to go both directions through that 17 feet of 8ga wire. 
The battery is simply not able to get a full charge, it's bottle-necked by the length of the small wire. That's why it's resting in the 11s. 

chrisb33, the slight drop after the engine is running for a bit is normal. As far as dropping further when you rev, I dunno. Maybe it's trying so hard to charge the battery that the voltage gauge (connected up front, I'm sure) is simply seeing a voltage drop from the distance from its connection point to the back as well. Your battery should be resting in the mid 12s when everything is off. If it's not, but the battery checks out fine, then it's just not getting a full charge. This could either be grounds (which you've addressed), alternator (which you've upgraded), or charging wire (my hunch).


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## rc10mike (Mar 27, 2008)

Are you sure you have genuine 8awg? Ive seen "8awg" wire with only about 16awg of actual wire inside...


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## MarkZ (Dec 5, 2005)

TREETOP said:


> MarkZ, think of it this way-
> Let's estimate the length of the charge wire at 17' long.
> All engine/electronics connections are up front, just the battery (and likely the audio) connected in back.
> Thinking of the battery as a buffer for the electrical system, anything needed over the alternator's output is drawn from the battery. Well, the battery never gets a full charge because it's being drawn from up front while the alternator is trying to recharge it, power is obviously having to go both directions through that 17 feet of 8ga wire.
> ...


Treetop, your explanation doesn't make any sense at all. The voltage isn't going to be reduced by delivering more current. Why? Because it cannot deliver more current when the potential between the alternator and battery is reduced. This is ohm's law.

I know you guys insist on tree trunk wire, but please look at the _symptoms_ he's describing.


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## sqshoestring (Jun 19, 2007)

How big is the wire from the original battery location to the rear mounted battery? I don't think you could start the engine on one 8ga wire that long, and I have no clue why a person would run a new wire alternator to the rear battery. A stock alt wire is typically 8ga or so and pretty short, unless your new alternator puts out far more current it should work fine.

That running voltage looks fine to me, typical in some cars I've seen. It should be over 12 at rest your battery or meter is bad if not, should be close to 12.5v give or take. Voltage regulators always run higher voltage when cold, I can get 14.5v all the time here in the winter until it warms up, but not in the summer.

Anyway, if you are worried about 13.5 to 14.5 volts difference, just go buy larger amps obviously they are not large enough....and that one volt is not going to be something you can hear the difference in. My alt is 125a and I could drop the voltage at idle with a little kicker 700.5, but not at higher rpm. It peaked at 74A draw clipping it hard with a clamp on, 40a rms or less, though I never listened to music with it clipping.

BTW power has no problems going 'both directions' in a wire. But everyone should know you always run a pretty large wire to remote mount a battery or you will not be able to run the starter. I'd say the issue is voltage fluctuation due to the voltage reg in the car and the remote battery mount and the fact that you only have one battery. I would put more battery in or a huge cap might help. If you then want to fiddle with a different voltage regulator and overcharge your batteries or something, go ahead but you are wasting your time unless you do SPL comps. You could also see if you can increase the idle speed or change the pulley if idle voltage is an issue.


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## Mopar3 (Aug 27, 2010)

Battery should be over 12 volts engine off. If the battery is good, starting, ok I'd be looking at and double checking your meter.


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## TREETOP (Feb 11, 2009)

MarkZ said:


> Treetop, your explanation doesn't make any sense at all.


It's not my theory that's unsound, it's my method of explanation. Having a hard time putting it into words.


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