High Output Alternator Questions

[ToXicFrOgXx 7]

Hi everybody. I just installed my new high output alternator today hoping that it would stop my voltage from dropping like what would happen with the stock alternator. But it didn't. It sits at 14.1 volts where as the stock alternator sat at 14.4. I did all the big 3 upgrade wires in 0 awg wire as well. I am running a bzr1200.1d at 2 ohms with a 12" Type R D4. At 14.4 volts its supposed to push 900 wrms but the new 180amp alternator has the same voltage drop that the stock alternator had... Why isn't the new alternator keeping the voltage up?? Im not even pulling anywhere near 180 amps. Any input would be awesome.

[1two3 16]

U shouldn't really need a HO alt for that little amount of draw. What company alternator? New or used? What battery/s do u have? What was the output of the stock alt?

[SacredTanakh 67]

could be that the alternator charges at 14.1v

Mine charges at 14.7v

 

not all alternators charge at 14.4v

Edited April 25, 2013 by SacredTanakh

[jonbearsmt 919]

if its the Camry some of them have had that issue

[edouble101 314]

Three letters.....PCM.

Your vehicle's computer controls alternator output. Voltage dips and spikes will still happen. If voltage drops under 13.6-13.8 and stays there look at your amplifer wiring. Specifically, is your ground good?

Also how are you measuring voltage? Vehicle at idle?

[ToXicFrOgXx 7]

The reason for the high output alternator is for my FI Bl 15 I have on order. It is a Singer alternator. The stock put out 80 amps and I had a lot of light dimming when I turn the bass nob all the way up and still have a lot of voltage dropping. I measure the voltage with a Stinger volt meter tapped into my head unit wires. I also have an Interstate battery under the hood that is about 4 years old. I was hoping the alternator would stop the voltage drop and won't have enough money to upgrade anything else for a while. The voltage drops when I put my brakes on and come to idle but retires to 14 volts. My amps are grounded to the rear seatbelt bolt. Sanded to bare metal.

[jonbearsmt 919]

 thats all normal, the alternator is made to put out power at a raise RPM. 1800 or so normal . all h/os are like  that,  unless its build for SPL then its high output at low RPM and low output at high RPm.

 

 its normal. you should be either idled up while playing hard or driving ( RPMS up) when your playing any how.

[ToXicFrOgXx 7]

Even while Im driving at 2000 rpms the voltage drops when the bass hits hard. But doesn't stay low. Its more like dancing around between 12.9 and 14.1 volts. I plan on running my BL at 1200 wrms until I upgrade to something around 1500 wrms. If there is his much voltage dance at 900 wrms will combined amps running around 2000 wrms total be to much for the alternator??

[shizzzon 461]

if you are dipping to 12.9v and that meter is accurate, that means it's dipping below the battery's surface charge... 

 

Hence.. that really isn't the surface charge of your battery right now.. which is not good... 

 

Shut off vehicle for a minimum of 2hrs and then measure voltage with vehicle OFF.  IF you start it, you did it wrong.

 

That battery should be resting around 12.9-13.0v if agm and around 12.7-12.8v if flooded.

 

Because it's 4 yrs old, depending on cycle use, it's possible it's resting lower.  

 

How low you state is dependent on if you need a new battery or not.

[ToXicFrOgXx 7]

After allowing my car to sit all night. When I get up in the morning for class the meter reads 11.8 to 12 volts usually before starting. So Im feeling that my battery is reaching the end of its life. I just checked the date when it was purchased and its coming up on exactly 3 years old. It has been through very hard weather conditions though. Ranging from below 0 to over 100. Will my alternator be okay until I can purchase a new battery around August??

[ToXicFrOgXx 7]

This morning before even putting the key in the ignition I measured the battery with a multimeter. It was sitting at 12.5 volts. After turning on the accessories the voltage dropped to around 12.2 volts. And after turning the ignition on the voltage dropped to 11.9 volts. When I started the car the alternator was putting out a steady 14.5 volts with no music on while I drove about 10 min to the store. Then after coming out of the store the alternator sat at 14.2 volts. Then after playing some music I noticed that at the initial hit of the bass the voltage would drop into the 13's but always come back up to 14.1-14.2 volts. Now I'm guessing that this is from the computer trying to keep up with the music.

[frogcase2002 393]

How is your gain set? All your grounds to bare metal?

[jonbearsmt 919]

what voltage gauge are you using?

[frogcase2002 393]

what voltage gauge are you using?

" I measure the voltage with a Stinger volt meter tapped into my head unit wires"

[jonbearsmt 919]

what voltage gauge are you using?

" I measure the voltage with a Stinger volt meter tapped into my head unit wires"

  i remember reading that now.. F me right!

[frogcase2002 393]

what voltage gauge are you using?

" I measure the voltage with a Stinger volt meter tapped into my head unit wires"

  i remember reading that now.. F me right!

Lol. . I'm thinking the gain is just way up. . And also needs some kind of storage even having a ho alt.

[muddybass 13]

Your Singer Alternator should have a ground post on it you can ground that one straight to the chassis or frame? The internal regulator on your alternator probably charges at 14.5 when cold and like you said 14.1-14.2 when hot which isn't bad. The internal regulator will fluxuate what it charges at. Considering your Battery is only resting at 12.5 I would say look into purchasing an agm battery. Keeping your resting voltage up will guarantee optimal performance. When you installed the alternator did you drop your belt size an inch? And did mike send you a smaller pulley at all? show some pics of the alternator

[ToXicFrOgXx 7]

I was able to tension the belt properly without getting a different size. It is equipped with the smaller pulley to increase idle output. My gains are set as following. SS: 30hz. Bass Boost half way up. Level somewhere near 2.5 volts. Low pass around 200 hz. I can post pictures of my gains after I get home from class if that can help. I ran 0 awg from + post on alternator to + on batt. Negative from batt to drivers side shock tower bolt and negative from mounting bolt for alternator to passenger side shock tower bolt. What is an agm battery?? The Interstate battery I had before lasted 8 years but that was before my stereo system started growing. Is it possible I killed this battery in 3 years after running the 900 wrms for just a year?? Thanks for all your help everybody.

[ToXicFrOgXx 7]

[muddybass 13]

your terminals look pretty corroded. It all depends do you play the system with the car off? do you check the fluids in the battery regularly? An AGM battery stands for absorbed glass mat basically its better in all applications... and your low pass being set at 200hz is very high in my opinion 

[muddybass 13]

_{my alternator charges at 14.8 when cold and drops to 14.4 when hot but the regulator will sometime even drop it to 14}

[edouble101 314]

Like I said voltage fluctuation will happen. The smaller pulley on your new h.o. alt should help it at idle but possibly the alt rpm still isn't high enough to get good amperage out of it at idle. That could just be how it is.

 

Your battery reserve seems low. Voltage maybe ok but that doesn't mean that the battery is in good shape. Can you take you vehicle into a reputable repair shop and have them load test your battery?  This would help you decide if a new battery would be helpful.

 

Since you have a uni-body I recommend you run a dedicated ground wire from the front battery to your subwoofer amplifier or ground distribution block. 

 

And as mentioned, clean up your battery terminals and check all connections.

[edouble101 314]

If you decide to add a ground wire use as large as you possibly can. 2/0 welding cable works great for car audio.

[ToXicFrOgXx 7]

Battery terminals are on my list of upgrades... I contacted Mike and he told me to run a direct ground from the negative batt post to the mounting bolt of the alternator to yeild the best ground possible. Should I just run a piece of 0 awg from the mounting bolt on the alternator to the batt negative and then the batt negative to the shock mount to ground that??. I do not play my stereo when the car is off and if I do it is at very low volume with the sub turned all the way down. As for the ground from the amps to the front battery post?? I was told that the ground should not be longer than 2 feet??

[edouble101 314]

The length of your ground doesnt matter as long as you use the appropriate size gaug (bigger than needed is always better, least resistance) wire for the total amplifier current draw. Ground wire length is a huge misconception.

Grounding your alt to battery will do nothing. You already have an upgraded engine ground.

Edited April 25, 2013 by edouble101