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4 batteries, 2 caps, stock alternator

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Member - Posts: 32
Member spacespace
Joined: March†18, 2006
Location: United States
Posted: June†29, 2006 at 2:30 PM / IP Logged  

I know that this topic has been beat to death, and I expect to get some opinionated responses.. but unless you can tell me exactly WHY my system runs as well as it does when the car is running and WITHOUT the h/o alternator, then please don't just tell me to just go buy a h/o alt. Here's my setup:

1997 Plymouth Grand Voyager Minivan (soccer practice never sounded so good..)

1 x standard car battery

1 x Stinger red cap battery
2 x 6 volt (ran in series) deep cycle, non-spillable batteries intended for back-up power for business computer systems (75lbs. each)

I have the three ran parallel with a relay/isolator at the car battery. I have a Kole 2.5 farad cap and a Power Ackoustic 6 farad cap.

I'm running 2 x 12" DDaudio 9500's (F series) and an Orion 15" H2 (2006). I won't go into the mids and highs, but there's a lot.
2 x Kenwood 25th Anniversary Excelon Mono amps (about 1000w RMS/each)
2 x Kenwood 9152D mono amps (about 1000w RMS/each)
1 x Kenwood Excelon KAC-X542 / 4-channel amp (960w RMS)

I'm trying to figure out how my extra batteries and caps make a HUGE difference when my car is running. My lights don't dim anymore, my system sounds great and everything stays charged. Regardless of how many of you say that extra batteries do not help when the car is running, this works and I'm trying to understand why. The digital readouts on my caps usually say about 13.7 volts when the car is on. Before adding the deep cycle batteries that number would dip down to 11 volts or lower during loud bass hits. Now it never goes below 12.5 and usually stays pretty steady in the mid 13ís.

You know, I think I just answered my own question. The alternator supplies power as much as it can until the draw brings the voltage down to the level of the batteries. At that point the power is drawn from the batteries keeping the voltage from dropping below 12v. Does that make sense? If so, then the extra batteries and caps DO help and all those statements I have read about them being useless with the engine running are very misleading.

The other question is concerning my charging system. I plug a 12v deep cycle battery charger in at my home about once a week or so and let it charge the system over night. I donít disconnect the batteries but just hook it up to the positive of one 6v and the negative of the other. It usually seems to charge all the batteries without problem and I keep a close watch with my multi-meter. This morning I unhooked it and I guess the automatic turn-off didn't kick in and the batteries are reading at around 15v (each 6v is at like 7.8). What happens if a battery gets over-charged? Should I do something before I start my car?

2 x DD9515f's, Digital Designs Z1 amplifier
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Joined: December†03, 2004
Location: California, United States
Posted: June†29, 2006 at 2:45 PM / IP Logged  

Your system runs fine the way it is because everything is new and fresh, the batteries at least. They will continue to do so for a while, until a point comes where they need to be recharged, then your alternator will be taxed tremendously in order to recharge all of those batteries and caps.

I think the real question that should be adressed here is why you have two 12's and a 15"4 batteries, 2 caps, stock alternator -- posted image.

Member - Posts: 32
Member spacespace
Joined: March†18, 2006
Location: United States
Posted: June†29, 2006 at 4:03 PM / IP Logged  

Thanks for the reply.. although I wasn't asking if it was going to damage my alternator. I have a relay that prevents that. You must have missed the part where I explained my charging system. My question had to do with the benefit of running multiple batteries even when your car is running.

Why wouldn't I run two 12's and a 15? I have a pair of 10's I will be putting back in soon as well. I have an active crossover system and some serious sound processors with my 29 speaker set-up. If you heard my system you would probably change your opinion on that matter.

2 x DD9515f's, Digital Designs Z1 amplifier
Copper - Posts: 154
Copper spacespace
Joined: January†06, 2006
Location: United States
Posted: June†29, 2006 at 4:20 PM / IP Logged  
what dwarren said. apparently your system is provided enough power from your batteries. but you have to charge them weekly. you don't have a problem with this? is this a daily driver? very inconvenient! your setup lends very little support to the argument of the effectiveness of using batteries and caps to prevent light dimming. stop charging your batteries weekly and you'll see the point.
Prove your connections, use a meter!
I promise, I'll behave!
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Joined: March†07, 2002
Location: Louisiana, United States
Posted: June†29, 2006 at 4:51 PM / IP Logged  
qnretail, even though you did not ask if you were going to damage your alternator, the "relay/isolator" will not prevent damage to your alternator and eventually your alternator will fail. As much as you don't want to hear it, you do need a high output alternator. Yes, for now the batteries and cap are baring the brunt of the load you've put on your electrical system as long as they are charged, however to keep them charged properly you will, once again, need a high output alternator, plain and simple, end of story. If you don't believe me and everyone else that has told you the same, leave your electrical system as it is and you will find that you will begin using your battery charger more than just once a week or so until the inevitable happens.... toasted diodes in your alternator which will lead to noise in your system and possibly leave you stranded on the side of the road.
4 batteries, 2 caps, stock alternator -- posted image. the12volt ē Support
Copper - Posts: 630
Copper spacespace
Joined: January†27, 2003
Location: Idaho, United States
Posted: June†29, 2006 at 5:11 PM / IP Logged  
Your alternator will put out what it can as long as it can. It would have been cheaper to just buy a HO alternator than spend the money on all the batteries and caps. If you spend alot of time with the vehicle off, your alternator is working it's guts out to charge all those batteries when you start it back up. Don't expect long life out it. Chances are it will fail at the worst time possible! according to Murphy...
Overvoltage and or overcharging with sealed gel batteries will drestroy them! Look and see if the sides have bowed out or if they have expanded anywhere. They operate in a very narrow range of voltage and temperature. Plus the 150 lbs of weight.
Audio wise, I'm not sure what to make of your system:
8 Amp channels and 29 speakers???
The x2 12's and the single 15" ???? And then a pair of 10"s ???
Explain exactly what you are calling "serious" processing.
Are you getting less than 10 mpg hauling all this weight around?
More isn't always better!! I think you need to post some pictures of your vehicle.
Silver - Posts: 527
Silver spacespace
Joined: October†06, 2005
Location: United States
Posted: June†29, 2006 at 6:30 PM / IP Logged  
qnretail...  How long do you usually run without charging your system?  If your trip is shorter than the batteries are able to supply power for, then you will not notice any problems with.  It's kind of like a gas tank.  If you have a full gas tank but a trip only requires half a tank, then you won't run out of gas.  If the trip takes one and a third tanks to make the treck, then you'll run into a problem.  You haven't gone to the point in which the batteries are empty.  When that occurs you will notice major problems.  If you spent tons of money on batteries and and left out an alternator, then it could last a while before you notice problems.  It's just a lot cheaper to buy a nice H.O. alternator.  That's just my personal opinion and if the example didn't make sense...  I'm sorry.
That's my opinion. Take it, leave it, or correct me.
Member - Posts: 32
Member spacespace
Joined: March†18, 2006
Location: United States
Posted: June†30, 2006 at 9:58 AM / IP Logged  

Thanks for the valuable input. Just to clarify, I'm not trying to say that a H/O alternator would not help my system. I know it would, and eventually I intend to upgrade this aspect of the system. I am unsure if I intend to keep this vehicle, so that has been the main deterrent for this upgrade. As far as the elaborate set-up is concerned.. it's been an ongoing experiment. Phase and cancellation, crossover adjustments, wiring configurations, etc. etc.. I just want to know how all of it works and eventually I will tone it down to what I like the best.

The reason for this thread was to find out WHY the batteries and caps were making a difference in my set-up because I kept reading other threads stating that they were useless while the car was running. Itís not that I am trying to talk my way out of buying the h/o alt, itís that I already know I need that. I just didnít understand how the batteries were making such a difference and I wanted to find that out instead of just hearing more of what I already know. Now I understand that they are not useless, but†I cannot rely on my alternator to keep them charged. I don't think I need to charge the†batteries at my house on a weekly basis either.. I probably just have too much time on my hands. The two 6 volt batteries say 200 AH Ė 20 hour rate to 1.75 VPC @ 77 degrees F. I donít ever run the system for longer than 30 minutes or so at a time and Iíve never seen any of the batteries drop below 12 volts (or 6) although I see what you mean, arrow12, that I havenít dropped the full load on the alternator yet.

As far as spending money on the batteries.. they were all free from a friend who does back-up power supplies for business servers. I have like 60 of them. I get the caps and much of the other stuff through auctions for practically nothing because thatís the line of work Iím in. Although I havenít come across a H/O alternator at the auction yet..

So you think the use of different size subs is so uncommon? I tried running all 12ís, all 10ís, all 15ís.. I tried different combinations.. I just like the tightness of 10ís for the kick drum and the fat lows that the 15 can hit. And the DD 12ís are just ungodly. You guys will probably have a hay-day with this next part but here is the layout for the 29 speaker setup. I crossover each set of speakers starting at the subs with my ultra-low (15") to my mid-lows (12") to my high-lows (10"). If you work your way up with low-mids (6x9)(6.5), mid-mids (5x7)(5.25), and high-mids (4" & 3") and then the highs (tweeters) counting any two-way speakers as two separate drivers you will come up with the 29 speakers. Itís a lot, but itís really more of an experiment than anything. The sound processors were set-up by a friend who does acoustic design for theaters and the purpose is primarily to adjust the phase of each set of speakers to prevent excessive cancelation. It sounds complicated, but Iím telling you, the system sounds amazing. Iíll post some pictures once I finish cleaning up the install.

2 x DD9515f's, Digital Designs Z1 amplifier
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Joined: January†19, 2003
Location: Michigan, Bouvet Island
Posted: June†30, 2006 at 10:20 AM / IP Logged  
Speaking from experience, (and I am sure there are others who can speak from similar experiences) no matter HOW much processing you think you have or need, simplicity is best. The fewer speakers you have, properly crossed over and matched, the better your results will be. This I GUARANTEE you. Some of the FINEST and most expensive speaker systems in the world use one driver, with no signal processing at all. I have 5 drivers in my system - tweeters, mid-bass, and one sub. In my home system, I have 4 drivers - 2 12 inch woofers, and two 52 inch planar magnetics. Both of these systems sound better than any systems I have ever had, and I have had many!
A theater is a VERY different venue than a car. I have done theater installations also, and I thought the same way you do. I have discovered, however, you CANNOT sit that close to that many drivers, with that many crossover points and bandwidths, without cancellation and other destructive interferences... It is physically and acoustically IMPOSSIBLE.
Keep with your experiment, this is how everybody learns, however, please keep in mind the above "words of wisdom". I am glad it sounds good to you, that's what the ultimate goal is, however, go to some high-end audio shows, and pay attention to the driver compliments in the better speaker systems. With two notable exceptions (Wilson Audio Grand SLAMM, and the Revel Studio Salon - both around $75K a pair) nearly all truly world class speaker systems use as few drivers as possible - generally speaking, 3 at most. This is where most of my inspiration comes from, when I design all of my systems.
As far as your defense of the multiple woofer sizes, that's a fallacy. A properly chosen woofer, whatever the size, will provide PLENTY of depth of response in the car. I had a Ti10, and I thought the Ti12 would go deeper. I was wrong. (I'd go back to the 10, but it was destroyed in a car accident after I sold it to a 20 year old kid I know...) The 12 is notably faster, but the 10 actually went deeper - exactly the opposite of what everybody thinks to be the truth. Driver selection and proper enclosure construction techniques are FAR more important than the actual woofer choice(s), specifically referring to the size of the woofer.
It all reminds me of something that MoliŤre once said to Guy de Maupassant at a cafť in Vienna: "That's nice. You should write it down."
Member - Posts: 5
Member spacespace
Joined: June†26, 2006
Location: United States
Posted: June†30, 2006 at 2:04 PM / IP Logged  
I guarantee you it doesn't sound amazing.
In fact, I guarantee you it wouldn't sound more amazing than a properly setup 7-speakers setup. A 3-way front-stage, and a subwoofer.
4 batteries, 2 caps, stock alternator -- posted image.
I use fuses sparingly.
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