Okay, so a bit of background. I have a nissan quest. It's beyond fully loaded. Recently, the battery has been completely drained pretty much every morning, and I figure the alternator can't handle the draw. I've added up my current draw in amps, and it's around 176 full load, maybe a bit more. The stock alternator is 110amps. I'm looking at buying a new alternator, and the one I'm looking at right now is 200amps at around 2600 RPM, and 0g wire, and a deep cycle gel cell battery (maybe a optima yellow top, or a purple haze?). For right now, I think that should be fine. But, I'm no expert, that's why I'm here. In the near future, I'm thinking about getting a bigger sub/amp with quite the bit more draw, and also amping up my mids, so that throws another 30 amps or so on the load. All together, It'll probably be around 270 amps. will the 200 amp alternator still carry that? or will i need like a 300 amp alternator? it's pretty hard to find big alterators for a quest... and so the one i'm getting will no doubt be custom built, but i'd like to hear what you guys have to say about the size. i got another quote on a 220amp alternator, but i think it's at a higher rpm, and I'm usually only around 2,200 anyway. Thanks in advance!
Replies (8)
swez on 07/13/2007 23:04:23
Great question and well stated I might add! CLAP
You are on the right track here. These amps are well past what a stock system can handle and keep up with the loads mentioned. Here we look at the stock system as a baseline and figure if you turned on practically every electronic device at once, the stock system is often designed to give about 25-30% more than what is needed for add ons.
However, in real life, we normally use about 40-50% of the electrical systems full capacity at any given time. Just look at our owner's manual on fuse ratings and this will tell us what circuits are the biggest power consumers. (The higher the fuse rating, the more power it will draw... right?)
OK, that's the basics. In your case, we are looking at a few options to consider and none are cheap or easy in this vehicle:
1. Upgrade the entire electrical system (ALT, BAT and large power lines for your amps and feeders from the ALT/BAT and ground to chassis) Figure about 250-300 Amperes for your new ALT if you go solo on the ALT. A 2nd battery for your sub amps would be a good plan too. (Most employ a dual battery charging device that is common to RV's, Marine and larger Diesel trucks) More on this plan later.
2. One can also use dual ALT's and a dedicated battery kit to power AUX devices like amps and such. This means an expensive H/O ALT, perhaps a few batteries and fabrication of brackets to fit the additional ALT into the package under the hood. (This method is very expensive and only needed for the serious SPL Competitor or over the top Bassheads)
Your comments about RPM vs ALT output are correct. Most stock systems and general aftermarket replacements net about 50-60% of full power at idle speeds. As RPM goes up (ALT speed) the power output will also go up. We can use a smaller pully on the ALT, to get more ALT RPM speed and power from the ALT, when engine RPM is low. (That's a trick all SPL Competitors and Drag Racing guys know)
In this case, you are using strong amps now and plan to add more later right? Well, why not upgrade the stock ALT to a H/O version and use a smaller pulley conversion option. (Say 250-300 A's at full power) In addition, add an additional battery for your sub amps and use a dual battery charging kit. This is commonly called a Battery Isolation charging system. Read these a bit and study the concept before we go any further:
http://www.bcae1.com/charging.htm
http://www.bcae1.com/battiso.htm
Once you have these concepts clear in your mind, then we can discuss what option(s) make the most sense for your present and future needs.
Finally, your comments on a dead battery each day suggest a few possible problems:
1. The battery is shot and needs to be replaced (Mos likely issue)
2. There are devices that are drawing current when the van is not running and this is draining your battery (Possible, but can be fixed)
3. The ALT you have now is on its last legs and cannot manage the overloads when your audio gear is running (A quick test of the electrical system can confirm this)
One or more of these in combination will create that scenario. The logical thing to do first, is to have your charging system and battery check out by a tech. Most good autoparts dealers have equipment to test the ALT and BAT right in the parking lot of a service bay. In most cases, the service is free and you can even ask for a print out of the results. (NAPA, Pep Boys, Auto Zone and the like)
The other test they can perform, is a static current draw test. This is also a simple test with the proper equipment. They look at how much current the battery is passing to various devices connected to the battery with the engine off. If you have an alarm system and a few other add ons here, current draw will be under 3 amperes.
However, if the amps are always getting REMote power and stay on all the time, the current draw will be notably higher and this will drain a fully charged battery in 6-12 hours of sitting. (It's like leaving the parking lights on over night.) That will kill a fresh battery in a few hours.
Here, the static load discharge test will show how much current is leaving the battery when the engine is off and the key is removed. It can also help identify shorts in the electrical system that are draining your battery as well.
Comments?
Swez
JordyFoRealz on 07/13/2007 23:42:05
Thanks for your time, the links, and everything, It's been really helpful. I'll go get the electrical system tests done tomorrow morning, and I'll probobly go with a second battery in the back, As far as an isolation system, would you suggest a diode one? it seemed simpler... but I know simpler isn't always better, unfortunately. Also, about how much will they run me? Also, I'm not to great with abbreviations, h/o is high output, right? I'll talk to the guy I've been dealing with tomorrow also about getting an alternator that'll put out 250-300a's. So, I guess it's sounding like option one... anything else I need to know? I'll post an update tomarrow on everything, thanks a ton again.
JordyFoRealz on 07/13/2007 23:43:33
oh, also, what size isolator would I be looking at?
swez on 07/14/2007 00:53:24
I would opt for the solinoid type Isolation Charger design as it handle high currents and does minimal voltage drops on the lines. In your present case, a 200 amp model would probably do the job very well. The solinoid versions are simple to install, use, very reliable and low cost compared to the solid state diode types out there. At all points of the compass, you can't lose on the solinoid version isolator. (Easy to repair in most cases too... just burnish the contacts when they get rough or sticky)
I recall seeing 300 amp models from Stinger too, but that seems like over-kill. The inrush current of a charging battery is not that high unless the battery is totally drained.
Isolators will charge the primary starting battery first. Once that is up to charge, (A few minutes at most) then the isolator switches over to the secodary battery and keeps it charged as well.
It is recommended that both batteries be equal and matched. (Same maker, model # and power ratings) So worst case, you'll be looking at 2 like batteries and the Isolator. These are very easy to install and very reliable too.
If you live in a warmer climate and have less severe winters, consider a pair of Deep Cycle Optima batteries. (Yellow Top Series) They cost a bit more than OEM type Lead/acid batteries. But they can handle many deep discharge cycles and last notably longer too. A big plus here, they are gel cells and do not outgas combustible hydrogen gasses while charging. That's a big plus for batteries used inside the vehicle. They don't leak and can be mounted in any orientation as well.
http://cgi.ebay.com/ebaymotors/PAC-200-AMP-HIGH-CURRENT-ISOLATOR-DUAL-BATTERY_W0QQcmdZViewItemQQcategoryZ33574QQihZ010QQitemZ200128569167QQrdZ1
http://cgi.ebay.com/STINGER-SR200-HIGH-CURRENT-RELAY-ISOLATOR-DUAL-BATTERY_W0QQitemZ140136915923QQihZ004QQcategoryZ14932QQrdZ1QQcmdZViewItem
http://www.thediscountmall.com/mall/77684/sr200.html
I am enjoying this post! For a nice change, someone knows enough about their gear and system needs, asks great questions and takes recommendations carefully into consideration. HAPPY
Oh, H.O. or H/O means a High Output device. Sorry... we use a lot of jargon here to simplify common terms. You are correct and ask if I slip one on you that "Does not compute".
Keep in touch after you get your electrical system checked out. Am curious what they might find and suggest. (Let's see how the ol diagnostics skills were, based on the info available) I could be all wet... but willing to learn something new too. SMILE
Swez
JordyFoRealz on 07/14/2007 17:27:23
alright, so I went by pep boys, and I feel like an idiot. I didn't have my negative terminal all the way tightened down *sigh* Everything tested out okay, battery, alternator, etc. So the advice to go get the stuff tested may have saved me 900 bucks, or more. I guess we'll see tomorrow morning, but if it doesn't start, does that still mean I should get a new alternator, even if the test said mine was still going alright? I talked to the guy about a 300 amp one also, he said he was going to look into it, but that he thought the 220 was the highest it seemed like people would build. *shrugs*
swez on 07/14/2007 18:43:04
Man, am I glad I listen to "Car Talk" on PBS each week... If the car does not start, it may well be because your ALT is powering the system as you drive, but not charging the battery enough to start the next day.
Also, a loose cable connector is enough to keep the car from starting as the starter takes a good deal of current during the starter engage process. The loose ground post terminal may have been the only real issue here. (Incomplete circuit to the starter solinoid) When jumping the car with cables or a high amp charger would make a complete path and the car starts fine.
Good news, your ALT and BAT are up to snuff! That is worth the trip and the free test and no need to sweat this one anymore. Did they perform a static current draw test on the battery as well?
As for H/O ALT sources, several guys here have obtained good success buying from this company:
http://www.motorcityreman.com/high-amp-alternators.html
They don't list your vehicle specifically, but there might be one out there... just call and ask.
This van has the same basic platform as the Mercury Villager. The body style and interior appointments may be different, but mechanically they are the same and most parts should be interchangable. My guess is that they use a Mitsubishi ALT and that brand is almost bullet proof. That's why the ALT is still good after all the extra audio gear was installed. (Good yes, but perhaps not good enough)
Am wondering if it would worth a try to buy the Battery Isolator, a secondary battery and heavy gage wire kit now and install it to see how well it works on your present setup. The AUX battery will act like a solid reserve power source to your sub amp(s) and the isolator will keep both batteries charged as well. The thought here, is to take steps progressively and see how well things work as you go. (Easier on the wallet too) If you eventually need a H/O ALT, you have lost nothing nor spent money that would not be used anyway.
There is one other upgrade to mention. We call it the "Big 3" wiring upgrade. Here's a link that explains the steps and most guys who work on their own vehicles can do this without assistance from a mechanic:
http://www.sounddomain.com/ubbthreads.php/ubb/showflat/Number/312025/page/1#Post312025
In your application, use 1/0 wiring and the appropriate terminal hardware for both ALT/BAT and ground wires. You can leave the stock wires as is. Current takes the path of least resistance. Chances are good that your stock wires are #4-6 gage lines now. That won't cut it here. Larger wires carry more current and have less resistance per foot. It's a low cost upgrade that you would have to do anyway, so why not get it out of the way now.
Finally, this will buy you a little time to research H/O ALT options for this van. It may take a while to find one that drops right in and can deliver close to 250 amperes at full power. You'll probably want to run a smaller pulley on the H/O ALT as well. The smaller diameter pulley gives more ALT spinning speed at lower engine RPM. (More power at lower engine RPM's) A shorter drive belt may be needed, if the belt tensioner cannot make up the difference.
What say you?
Swez
JordyFoRealz on 07/17/2007 14:11:20
Okay, so I'm defiantly planning to do the big three, but for now, the last two days my car still hasn't started, and since everything else checked out fine, and when I jump it, it's fine, what do you suggest?
swez on 07/17/2007 17:33:50
I'd suggest a good mechanic have a closer look for the reason your vehicle won't start. It may be something very simple and mundane like a worn out starter, a bad solinoid switch or something a bit more difficult to track down.
Swez
PS Ask your mechanic to test for "parasitic drain" on the battery. He'll know exactly what that means and how to test it. (An ammeter is the correct diagnostic tool for this test)
Replies (8)
swez on 07/13/2007 23:04:23
Great question and well stated I might add! CLAP
You are on the right track here. These amps are well past what a stock system can handle and keep up with the loads mentioned. Here we look at the stock system as a baseline and figure if you turned on practically every electronic device at once, the stock system is often designed to give about 25-30% more than what is needed for add ons.
However, in real life, we normally use about 40-50% of the electrical systems full capacity at any given time. Just look at our owner's manual on fuse ratings and this will tell us what circuits are the biggest power consumers. (The higher the fuse rating, the more power it will draw... right?)
OK, that's the basics. In your case, we are looking at a few options to consider and none are cheap or easy in this vehicle:
1. Upgrade the entire electrical system (ALT, BAT and large power lines for your amps and feeders from the ALT/BAT and ground to chassis) Figure about 250-300 Amperes for your new ALT if you go solo on the ALT. A 2nd battery for your sub amps would be a good plan too. (Most employ a dual battery charging device that is common to RV's, Marine and larger Diesel trucks) More on this plan later.
2. One can also use dual ALT's and a dedicated battery kit to power AUX devices like amps and such. This means an expensive H/O ALT, perhaps a few batteries and fabrication of brackets to fit the additional ALT into the package under the hood. (This method is very expensive and only needed for the serious SPL Competitor or over the top Bassheads)
Your comments about RPM vs ALT output are correct. Most stock systems and general aftermarket replacements net about 50-60% of full power at idle speeds. As RPM goes up (ALT speed) the power output will also go up. We can use a smaller pully on the ALT, to get more ALT RPM speed and power from the ALT, when engine RPM is low. (That's a trick all SPL Competitors and Drag Racing guys know)
In this case, you are using strong amps now and plan to add more later right? Well, why not upgrade the stock ALT to a H/O version and use a smaller pulley conversion option. (Say 250-300 A's at full power) In addition, add an additional battery for your sub amps and use a dual battery charging kit. This is commonly called a Battery Isolation charging system. Read these a bit and study the concept before we go any further:
http://www.bcae1.com/charging.htm
http://www.bcae1.com/battiso.htm
Once you have these concepts clear in your mind, then we can discuss what option(s) make the most sense for your present and future needs.
Finally, your comments on a dead battery each day suggest a few possible problems:
1. The battery is shot and needs to be replaced (Mos likely issue)
2. There are devices that are drawing current when the van is not running and this is draining your battery (Possible, but can be fixed)
3. The ALT you have now is on its last legs and cannot manage the overloads when your audio gear is running (A quick test of the electrical system can confirm this)
One or more of these in combination will create that scenario. The logical thing to do first, is to have your charging system and battery check out by a tech. Most good autoparts dealers have equipment to test the ALT and BAT right in the parking lot of a service bay. In most cases, the service is free and you can even ask for a print out of the results. (NAPA, Pep Boys, Auto Zone and the like)
The other test they can perform, is a static current draw test. This is also a simple test with the proper equipment. They look at how much current the battery is passing to various devices connected to the battery with the engine off. If you have an alarm system and a few other add ons here, current draw will be under 3 amperes.
However, if the amps are always getting REMote power and stay on all the time, the current draw will be notably higher and this will drain a fully charged battery in 6-12 hours of sitting. (It's like leaving the parking lights on over night.) That will kill a fresh battery in a few hours.
Here, the static load discharge test will show how much current is leaving the battery when the engine is off and the key is removed. It can also help identify shorts in the electrical system that are draining your battery as well.
Comments?
Swez
JordyFoRealz on 07/13/2007 23:42:05
Thanks for your time, the links, and everything, It's been really helpful. I'll go get the electrical system tests done tomorrow morning, and I'll probobly go with a second battery in the back, As far as an isolation system, would you suggest a diode one? it seemed simpler... but I know simpler isn't always better, unfortunately. Also, about how much will they run me? Also, I'm not to great with abbreviations, h/o is high output, right? I'll talk to the guy I've been dealing with tomorrow also about getting an alternator that'll put out 250-300a's. So, I guess it's sounding like option one... anything else I need to know? I'll post an update tomarrow on everything, thanks a ton again.
JordyFoRealz on 07/13/2007 23:43:33
oh, also, what size isolator would I be looking at?
swez on 07/14/2007 00:53:24
I would opt for the solinoid type Isolation Charger design as it handle high currents and does minimal voltage drops on the lines. In your present case, a 200 amp model would probably do the job very well. The solinoid versions are simple to install, use, very reliable and low cost compared to the solid state diode types out there. At all points of the compass, you can't lose on the solinoid version isolator. (Easy to repair in most cases too... just burnish the contacts when they get rough or sticky)
I recall seeing 300 amp models from Stinger too, but that seems like over-kill. The inrush current of a charging battery is not that high unless the battery is totally drained.
Isolators will charge the primary starting battery first. Once that is up to charge, (A few minutes at most) then the isolator switches over to the secodary battery and keeps it charged as well.
It is recommended that both batteries be equal and matched. (Same maker, model # and power ratings) So worst case, you'll be looking at 2 like batteries and the Isolator. These are very easy to install and very reliable too.
If you live in a warmer climate and have less severe winters, consider a pair of Deep Cycle Optima batteries. (Yellow Top Series) They cost a bit more than OEM type Lead/acid batteries. But they can handle many deep discharge cycles and last notably longer too. A big plus here, they are gel cells and do not outgas combustible hydrogen gasses while charging. That's a big plus for batteries used inside the vehicle. They don't leak and can be mounted in any orientation as well.
http://cgi.ebay.com/ebaymotors/PAC-200-AMP-HIGH-CURRENT-ISOLATOR-DUAL-BATTERY_W0QQcmdZViewItemQQcategoryZ33574QQihZ010QQitemZ200128569167QQrdZ1
http://cgi.ebay.com/STINGER-SR200-HIGH-CURRENT-RELAY-ISOLATOR-DUAL-BATTERY_W0QQitemZ140136915923QQihZ004QQcategoryZ14932QQrdZ1QQcmdZViewItem
http://www.thediscountmall.com/mall/77684/sr200.html
I am enjoying this post! For a nice change, someone knows enough about their gear and system needs, asks great questions and takes recommendations carefully into consideration. HAPPY
Oh, H.O. or H/O means a High Output device. Sorry... we use a lot of jargon here to simplify common terms. You are correct and ask if I slip one on you that "Does not compute".
Keep in touch after you get your electrical system checked out. Am curious what they might find and suggest. (Let's see how the ol diagnostics skills were, based on the info available) I could be all wet... but willing to learn something new too. SMILE
Swez
JordyFoRealz on 07/14/2007 17:27:23
alright, so I went by pep boys, and I feel like an idiot. I didn't have my negative terminal all the way tightened down *sigh* Everything tested out okay, battery, alternator, etc. So the advice to go get the stuff tested may have saved me 900 bucks, or more. I guess we'll see tomorrow morning, but if it doesn't start, does that still mean I should get a new alternator, even if the test said mine was still going alright? I talked to the guy about a 300 amp one also, he said he was going to look into it, but that he thought the 220 was the highest it seemed like people would build. *shrugs*
swez on 07/14/2007 18:43:04
Man, am I glad I listen to "Car Talk" on PBS each week... If the car does not start, it may well be because your ALT is powering the system as you drive, but not charging the battery enough to start the next day.
Also, a loose cable connector is enough to keep the car from starting as the starter takes a good deal of current during the starter engage process. The loose ground post terminal may have been the only real issue here. (Incomplete circuit to the starter solinoid) When jumping the car with cables or a high amp charger would make a complete path and the car starts fine.
Good news, your ALT and BAT are up to snuff! That is worth the trip and the free test and no need to sweat this one anymore. Did they perform a static current draw test on the battery as well?
As for H/O ALT sources, several guys here have obtained good success buying from this company:
http://www.motorcityreman.com/high-amp-alternators.html
They don't list your vehicle specifically, but there might be one out there... just call and ask.
This van has the same basic platform as the Mercury Villager. The body style and interior appointments may be different, but mechanically they are the same and most parts should be interchangable. My guess is that they use a Mitsubishi ALT and that brand is almost bullet proof. That's why the ALT is still good after all the extra audio gear was installed. (Good yes, but perhaps not good enough)
Am wondering if it would worth a try to buy the Battery Isolator, a secondary battery and heavy gage wire kit now and install it to see how well it works on your present setup. The AUX battery will act like a solid reserve power source to your sub amp(s) and the isolator will keep both batteries charged as well. The thought here, is to take steps progressively and see how well things work as you go. (Easier on the wallet too) If you eventually need a H/O ALT, you have lost nothing nor spent money that would not be used anyway.
There is one other upgrade to mention. We call it the "Big 3" wiring upgrade. Here's a link that explains the steps and most guys who work on their own vehicles can do this without assistance from a mechanic:
http://www.sounddomain.com/ubbthreads.php/ubb/showflat/Number/312025/page/1#Post312025
In your application, use 1/0 wiring and the appropriate terminal hardware for both ALT/BAT and ground wires. You can leave the stock wires as is. Current takes the path of least resistance. Chances are good that your stock wires are #4-6 gage lines now. That won't cut it here. Larger wires carry more current and have less resistance per foot. It's a low cost upgrade that you would have to do anyway, so why not get it out of the way now.
Finally, this will buy you a little time to research H/O ALT options for this van. It may take a while to find one that drops right in and can deliver close to 250 amperes at full power. You'll probably want to run a smaller pulley on the H/O ALT as well. The smaller diameter pulley gives more ALT spinning speed at lower engine RPM. (More power at lower engine RPM's) A shorter drive belt may be needed, if the belt tensioner cannot make up the difference.
What say you?
Swez
JordyFoRealz on 07/17/2007 14:11:20
Okay, so I'm defiantly planning to do the big three, but for now, the last two days my car still hasn't started, and since everything else checked out fine, and when I jump it, it's fine, what do you suggest?
swez on 07/17/2007 17:33:50
I'd suggest a good mechanic have a closer look for the reason your vehicle won't start. It may be something very simple and mundane like a worn out starter, a bad solinoid switch or something a bit more difficult to track down.
Swez
PS Ask your mechanic to test for "parasitic drain" on the battery. He'll know exactly what that means and how to test it. (An ammeter is the correct diagnostic tool for this test)
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