A jl amp pulls a lot at lower voltage? Maybe that's why idle is suffering a bit? I'm speculating since I have this $400 alternator not supplying enough voltage with heater and lights on.

A jl amp pulls a lot at lower voltage? Maybe that's why idle is suffering a bit? I'm speculating since I have this $400 alternator not supplying enough voltage with heater and lights on.

All amplifiers are going to draw more current when the voltage is lower.

Rudimentary example:

Target output is 1000watts.

V*A=Watts

14.4v*70a = ~1000watts

12v*83a = ~1000watts

10v*100a = 1000watts

Your idle voltage is what it is because it's dropping to your batteries' float voltage. You can try giving your batteries a good charge and see if that helps stiffen the float voltage, and/or you need more battery reserve IF you want better voltage at idle.

A jl amp pulls a lot at lower voltage? Maybe that's why idle is suffering a bit? I'm speculating since I have this $400 alternator not supplying enough voltage with heater and lights on.

All amps are going to draw more current when the voltage is lower.

Rudimentary example:

Target output is 1000watts.

V*A=Watts

14.4v*70a = ~1000watts

12v*83a = ~1000watts

10v*100a = 1000watts

Something about the way JL describes their R.I.P.S power supply made me think it draws more than most "standard" power supplies...

If the power supply is regulated then yes, it will draw more current at lower voltages.

Common denominator is wattage output in regulated PS' so if voltage goes down, current must go up and vice versa.

A jl amp pulls a lot at lower voltage? Maybe that's why idle is suffering a bit? I'm speculating since I have this $400 alternator not supplying enough voltage with heater and lights on.

All amps are going to draw more current when the voltage is lower.

Rudimentary example:

Target output is 1000watts.

V*A=Watts

14.4v*70a = ~1000watts

12v*83a = ~1000watts

10v*100a = 1000watts

Something about the way JL describes their R.I.P.S power supply made me think it draws more than most "standard" power supplies...

Good read: http://www.diymobileaudio.com/forum/diyma-sq-forum-technical-advanced/89221-how-does-rips-jl-audio-work.html

A jl amp pulls a lot at lower voltage? Maybe that's why idle is suffering a bit? I'm speculating since I have this $400 alternator not supplying enough voltage with heater and lights on.

All amps are going to draw more current when the voltage is lower.

Rudimentary example:

Target output is 1000watts.

V*A=Watts

14.4v*70a = ~1000watts

12v*83a = ~1000watts

10v*100a = 1000watts

Something about the way JL describes their R.I.P.S power supply made me think it draws more than most "standard" power supplies...

Good read: http://www.diymobileaudio.com/forum/diyma-sq-forum-technical-advanced/89221-how-does-rips-jl-audio-work.html

I'll take a look later since my job blocks that site... Will look it over when I get home.. Thanks Stef

Good info here... my issue is that "cold" my alternator put out 15.0-15.1v while driving. And going to work it stays that high during the drive (20-45min).. just want to stay safe with all my gear. Do you

While driving it should be 14.6 14.8 while driving. Since its cold the alt probably just starting to feel the effects of that drive. So by the the time you get home its getting in the "normal" operating temp range. I went through a couple of ways of tinkering with the AVBM and in the end my results were yes the AVBM comes from mechman at the 15v cold range but my car revved up high beams on and AC fan on to simulate load I set the AVBM while touching the front battery post with a O scope and set it at 14.8v cold start while RPM was up and all that other stuff on. On the hottest summer days after a 30min drive my voltage would drop down to 14.2 14.3v. Now that its cooler without messing with anything it licks 15v at startup but then drops a tad down to 14.4 14.6v.

In the end if you charge batteries, triple check your grounds including the one off the negative output stud on the alt to the battery negative post it sucks to have this fall right under the alt's turn on speed. Obviously I do care to try to help you across close to tree different websites on just about the same topics. Good luck.

Good info here... my issue is that "cold" my alternator put out 15.0-15.1v while driving. And going to work it stays that high during the drive (20-45min).. just want to stay safe with all my gear. Do you

While driving it should be 14.6 14.8 while driving. Since its cold the alt probably just starting to feel the effects of that drive. So by the the time you get home its getting in the "normal" operating temp range. I went through a couple of ways of tinkering with the AVBM and in the end my results were yes the AVBM comes from mechman at the 15v cold range but my car revved up high beams on and AC fan on to simulate load I set the AVBM while touching the front battery post with a O scope and set it at 14.8v cold start while RPM was up and all that other stuff on. On the hottest summer days after a 30min drive my voltage would drop down to 14.2 14.3v. Now that its cooler without messing with anything it licks 15v at startup but then drops a tad down to 14.4 14.6v.

In the end if you charge batteries, triple check your grounds including the one off the negative output stud on the alt to the battery negative post it sucks to have this fall right under the alt's turn on speed. Obviously I do care to try to help you across close to tree different websites on just about the same topics. Good luck.

I do appreciate your help crunk... Thanks again mate... :fing34:

Gonna do all of the above and possibly get some new battery or batteries... We'll see what happens...

No problem! Some of us just have a curse on us when it comes to this hobby, and it gets expensive. Hell I have my fair share of gremlins in my car that needs working out. a year ago when I started my car I even ran 1/0 all the way from front battery positive to rear positive and a 1/0 negative run from rear battery negative back around to the front battery negative post.

I was reading I think it was either Matt or Eric said that really only the negative from the alt post to battery and the cars factory battery to block were enough for a good charge and overall performance. I can't remember where I saw it but its very recent.

If I find it I'll post it for you but you might stumble upon too.

One other thing to think about when the alternator is charging at the higher voltages while being cold, is that your battery is also cold and can take a little higher voltage. This is whey the alt can charge in the 15V range on initial start while it is cold and it not hurt the battery.

Nice price on those ctek 3300 chargers...gonna have to pick one up

From the looks of it that charger is probably good for doing one battery at a time.

Edited December 14, 201113 yr by crunkjuice1

hmmm...I'm gonna end up with a d3100 under the hood and 2 in the back

I'd really like the xs charger but don't have the coin for it right now

Edited December 14, 201113 yr by Tim Harmening

My wifa depositing funds for that very one right now. I had a schumacher charger but I felt it would have problems down the road because it had a moving part in it which sounded like a fan that the grease dried off of. I bought a battery tender plus a week and a half ago and it took a good while to do a S3100 and A D1200 by themselves if it was putting out the full 1.5amps charge. The schumacher was good about the 15amp output as it would charge them both connected in about 10min. Now the XS charger does the 15amps and can charge a battery bank pretty good, don't know if it has a cooling fan that will end up doing the same though.

Here you go Sho...

Quote..

Posted Yesterday, 08:33 AM

"You have a little resistance in your ground right now. Not a lot, but as your power output increases you need to increase ground capacity. Conducting ground through the alternator case, through the engine, through the chassis and then to the battery is not efficient.

There is no reason on a car audio vehicle to add an additional ground to the engine, it's not part of the charging system and the OEM ground is adequate for the OEM engine management. The ground needs to be improved for the alternator and the best way to do so is by directly grounding the alternator case.

12.5v is a bit low for resting voltage.

The alternator is charging at 14.7-14.8 at idle, this is good. Your voltage drop is going to be due to inadequate battery capacity (weak battery), bad grounds, excessive clipping, but not likely a problem with the alternator.

Keep in mind that your amplifier is powered by the battery, not the alternator, the alternator is there to maintain the battery. "

This was said in someone else's issue, but worth a read.

Thanks again crunk. Ill do a few things then but def want to get at least one better battery and maybe move the hc1800 to the rear or the other way around.

From the batteries I currently have which is XS S3400 under hood and a D1200 in the trunk, I've called XS to ask if there would be a difference in switching them and they said there really wouldn't be difference. I have them in parallel with each other directly connected. If your going to look into new battery or batteries take a look at the XSpower chart. It shows you how each battery does alone and as a secondary battery.

If I decide to keep this car going my plan is to get one D3100 in the trunk, because you have to also take the 4ch into account and from what I've read the AB class amp is kinda on the power hungry side now add in that BC3500 and I will want a good amount of battery reserve, and that D3100 should hold up pretty good linked to the S3400.

I would aim at one D3100 for the trunk and keep the HC1800 up front.

Edited December 15, 201113 yr by crunkjuice1

From the batteries I currently have which is XS S3400 under hood and a D1200 in the trunk, I've called XS to ask if there would be a difference in switching them and they said there really wouldn't be difference. I have them in parallel with each other directly connected. If your going to look into new battery or batteries take a look at the XSpower chart. It shows you how each battery does alone and as a secondary battery.

If I decide to keep this car going my plan is to get one D3100 in the trunk, because you have to also take the 4ch into account and from what I've read the AB class amp is kinda on the power hungry side now add in that BC3500 and I will want a good amount of battery reserve, and that D3100 should hold up pretty good linked to the S3400.

I would aim at one D3100 for the trunk and keep the HC1800 up front.

I'm thinking a d3100 or equivalent in the trunk

Here you go Sho...

Quote..

Posted Yesterday, 08:33 AM

"You have a little resistance in your ground right now. Not a lot, but as your power output increases you need to increase ground capacity. Conducting ground through the alternator case, through the engine, through the chassis and then to the battery is not efficient.

There is no reason on a car audio vehicle to add an additional ground to the engine, it's not part of the charging system and the OEM ground is adequate for the OEM engine management. The ground needs to be improved for the alternator and the best way to do so is by directly grounding the alternator case.

12.5v is a bit low for resting voltage.

The alternator is charging at 14.7-14.8 at idle, this is good. Your voltage drop is going to be due to inadequate battery capacity (weak battery), bad grounds, excessive clipping, but not likely a problem with the alternator.

Keep in mind that your amplifier is powered by the battery, not the alternator, the alternator is there to maintain the battery. "

This was said in someone else's issue, but worth a read.

ok, with you saying 12.5v is a bit low for resting voltage. I got an XS power D5100r in last week and I read the voltage when it got here and it was at 12.5. I put it on charger over night and it was charging up to 14.5v. When I would take it off the charger, it would drop back down to 12.5. I am using a CTEK Multi US 3300 that was mentioned earlier in this thread. Do I have a bad battery?

Trust me guys, 99% of everybody with ho alts in car audio charge around 15v.

Nobody has problems because you are looking at it wrong.

Specifically= EXTENDED PERIODS of time.

An alternator charges so fast compared to a charger that there is no such thing as extended period of time for an alt unless you were driving half way across the country and never turned the stereo down.... EVER, and the current draw was surpassing the alternator's capability all the time.

my stock alt charges at 15v not altered either

Trust me guys, 99% of everybody with ho alts in car audio charge around 15v.

Nobody has problems because you are looking at it wrong.

Specifically= EXTENDED PERIODS of time.

An alternator charges so fast compared to a charger that there is no such thing as extended period of time for an alt unless you were driving half way across the country and never turned the stereo down.... EVER, and the current draw was surpassing the alternator's capability all the time.

my stock alt charges at 15v not altered either

Yea yea...lol

Here you go Sho...

Quote..

Posted Yesterday, 08:33 AM

"You have a little resistance in your ground right now. Not a lot, but as your power output increases you need to increase ground capacity. Conducting ground through the alternator case, through the engine, through the chassis and then to the battery is not efficient.

There is no reason on a car audio vehicle to add an additional ground to the engine, it's not part of the charging system and the OEM ground is adequate for the OEM engine management. The ground needs to be improved for the alternator and the best way to do so is by directly grounding the alternator case.

12.5v is a bit low for resting voltage.

The alternator is charging at 14.7-14.8 at idle, this is good. Your voltage drop is going to be due to inadequate battery capacity (weak battery), bad grounds, excessive clipping, but not likely a problem with the alternator.

Keep in mind that your amplifier is powered by the battery, not the alternator, the alternator is there to maintain the battery. "

This was said in someone else's issue, but worth a read.

ok, with you saying 12.5v is a bit low for resting voltage. I got an XS power D5100r in last week and I read the voltage when it got here and it was at 12.5. I put it on charger over night and it was charging up to 14.5v. When I would take it off the charger, it would drop back down to 12.5. I am using a CTEK Multi US 3300 that was mentioned earlier in this thread. Do I have a bad battery?

I want to know as I'm also interested in the CTEK charger.

That charger is a .8/3.3amp charger. It will take a long time for that charger to charge up a larger size battery (group 51 and up). For instance our D5100 and larger batteries have an optimal amperage charge rate of 15amps. That charger will charge the batteries, but it will take a long time to charge them up fully.

That charger is a .8/3.3amp charger. It will take a long time for that charger to charge up a larger size battery (group 51 and up). For instance our D5100 and larger batteries have an optimal amperage charge rate of 15amps. That charger will charge the batteries, but it will take a long time to charge them up fully.

I have a ten amp charger for my two bats and it will take a full 15hrs plus to charge them. 3400 series

Here you go Sho...

Quote..

Posted Yesterday, 08:33 AM

"You have a little resistance in your ground right now. Not a lot, but as your power output increases you need to increase ground capacity. Conducting ground through the alternator case, through the engine, through the chassis and then to the battery is not efficient.

There is no reason on a car audio vehicle to add an additional ground to the engine, it's not part of the charging system and the OEM ground is adequate for the OEM engine management. The ground needs to be improved for the alternator and the best way to do so is by directly grounding the alternator case.

12.5v is a bit low for resting voltage.

The alternator is charging at 14.7-14.8 at idle, this is good. Your voltage drop is going to be due to inadequate battery capacity (weak battery), bad grounds, excessive clipping, but not likely a problem with the alternator.

Keep in mind that your amplifier is powered by the battery, not the alternator, the alternator is there to maintain the battery. "

This was said in someone else's issue, but worth a read.

ok, with you saying 12.5v is a bit low for resting voltage. I got an XS power D5100r in last week and I read the voltage when it got here and it was at 12.5. I put it on charger over night and it was charging up to 14.5v. When I would take it off the charger, it would drop back down to 12.5. I am using a CTEK Multi US 3300 that was mentioned earlier in this thread. Do I have a bad battery?

I want to know as I'm also interested in the CTEK charger.

It is also there to give the battery help when you run extra electrical equipment. Like the blower,ac etc.