Boon Posted June 23, 2008 Report Share Posted June 23, 2008 Ok, Slowly planning out a bit more of my system and giving a bit of thought to the electrical side of things. I have the following batteries: 1x 105Ah beast up front (equivalent to Kinetik HC2400) 10x 18Ah AGM batteries in the back (Good for 250A each @ 15 second burst) There's 8 runs of 0ga running front to back (for Street class SPL when I disconnect the rear bank) so I'm not worried about that part. I'm also not particularly worried about the alternator's capacity. My system at full draw is going to pull over 1000A and there's no way I can fit a multiple alt setup (maybe 2 at best) so I'm resigned to running from the batteries. What I'm mostly worried about is charging the batteries if I do pull a bit of power off them. I have a sneaky feeling that trying to charge that many batteries off a single 90A alt isn't going to be good for it. Also I have read that AGM batteries (which all of mine are) charge best with 15v+ My alt only puts out 14.4v (solidly though) or maybe 14.8-15v when it's very cold. Should I invest in a good high-power charger to top up each night when the car is in the garage? I'm interested in people's thoughts on the matter... Quote 10.x volts fo' life! Link to comment Share on other sites More sharing options...
missinglink Posted June 23, 2008 Report Share Posted June 23, 2008 Well I run 13 batteries @ 16.2v off duel alts. They float @ 13+ volts MLA Quote missinglinkaudio The United States Marine Corps. When it absolutely, positively has to be destroyed overnight - even if "it" belongs to the base commander... Link to comment Share on other sites More sharing options...
wL<3bass Posted June 23, 2008 Report Share Posted June 23, 2008 Won't all those batteries draw all 90amps just to keep them charged? or is that what the disconnect is for? Quote Vehicle: 1997 S10 Blazer 4dr 4X4 Exterior: Rear End Bagged, Black Grill, Lifted 2" Amplifiers: Rockford Fosgate T8004 & T10001bd Batteries: 2 Stinger SPV35, Kinetik HC2400 Electrical: Big 3, DC Power 290amp Alternator w/ MLA at 15.5v Enclosure: 4.2 ft³ @ 33Hz 84sq.in. of port (20sq.in. per cube) Headunit: Eclipse CD3200 w/ 80G iPod Mids/Highs: Rockford T152s (a-pillars), Rockford T162s (doors) Subwoofers: 1 15" Fi BL Fully Loaded Wire: All 1/0g Kicker Hyperflex My YouTube Videos My Fiberglass A-Pillar Build My "Seamless" Looking Box Build My DD1508 T-Line Bandpass Build "Seamless" w/ Acrylic Windows (for '05 TrailBlazer) My Stealth 8" Fiberglass Build (for '05 TrailBlazer) My Build For A Friend's '08 Cobalt 15" BL Sealed Off From The Trunk My feedback/references... Link to comment Share on other sites More sharing options...
Boon Posted June 23, 2008 Author Report Share Posted June 23, 2008 Won't all those batteries draw all 90amps just to keep them charged? or is that what the disconnect is for? That's what I'm worried about :S The disconnect is going to be a matter of pulling the battery bank wires off the bus-bars in the back, it'll be a very manual-labour type thing and only for the sake of rules to stay in Street Max rather than Super Street 1-2... for daily driving etc it will all be connected, all the time. Quote 10.x volts fo' life! Link to comment Share on other sites More sharing options...
missinglink Posted June 23, 2008 Report Share Posted June 23, 2008 What I'm mostly worried about is charging the batteries if I do pull a bit of power off them. I have a sneaky feeling that trying to charge that many batteries off a single 90A alt isn't going to be good for it. Your toyo's little nippondenso alternator will do all it can, but there are limits. That alternator has an internal regulator with thermal sensing. It will back off if it is running too hot. You will not hurt it, but you will not be able to charge all of that battery bank if it is badly depleted. Also I have read that AGM batteries (which all of mine are) charge best with 15v+ AGM's respond well to higher voltages, if the current is well controlled. Depending on the brand & chemistry, 15+ volts can be very benificial. My alt only puts out 14.4v (solidly though) or maybe 14.8-15v when it's very cold. Should I invest in a good high-power charger to top up each night when the car is in the garage? In this particular application I would say you absolutely need to have AC charging available. High current charging for bulk charge is fine, you may also want a higher voltage trickle charge for cell balancing. Most AGM's need to see the 15+ volts occasionally for cell balance. Even Chris' outrageous H2 has managed to get out of balance once. A bench type regulated power supply will work fine for your system. Set the voltage about 15.3, and the current limit around 1 amp. Charge for 1/10c, and measure the resting voltage of the cells after 4 (or more) hours off charge. Adjust charging times accordingly. We can of course adjust the vehicle charging voltage up, but your money is best spent on a power supply at this time. Any decent battery charger will put the bulk of the charge back into the cells, but to get all of the performance available takes more managment. 'Link Quote missinglinkaudio The United States Marine Corps. When it absolutely, positively has to be destroyed overnight - even if "it" belongs to the base commander... Link to comment Share on other sites More sharing options...
MECHMAN Posted June 23, 2008 Report Share Posted June 23, 2008 I wouldn't charge any 12V AGM battery over 14.9 volts, it will cook the batteries over time. As long as you don't let your bank of batteries run down before you start the vehicle, you will be fine. I use a Powermaster charger to charge a bank of 10 batteries and it seems to work well. Quote 1-888-MECHMAN www.Mechman.com [email protected] Link to comment Share on other sites More sharing options...
AI James Posted June 23, 2008 Report Share Posted June 23, 2008 I wouldn't charge any 12V AGM battery over 14.9 volts, it will cook the batteries over time. As long as you don't let your bank of batteries run down before you start the vehicle, you will be fine. I use a Powermaster charger to charge a bank of 10 batteries and it seems to work well. I totally agree, and this is one of the reasons i stopped looking at the MLA module. I'll wait and see over time how some of the people who bought thems stuff goes. Quote Link to comment Share on other sites More sharing options...
missinglink Posted June 24, 2008 Report Share Posted June 24, 2008 I totally agree, and this is one of the reasons i stopped looking at the MLA module. I'll wait and see over time how some of the people who bought thems stuff goes. Well kids, reading is fundamental. My post above outlines using a 15+ volt balancing charge for multiple battery banks, and suggests a 10% of capacity charge before checking resting voltages. At no time did I suggest charging at a constant 15+ volts Modern AGM batteries are recombinant, and very difficult to "cook" or dry out. Some gassing must occur for the high rates they are capable of. AGM batteries are designed to deal with this by recombining the hydrogen & oxygen to produce water - which is retained in the cell. If you were to do something really stupid, like use an adjustable regulator set at a fixed 16 volts you would over time damage a VRLA type AGM battery. The MLA module does not charge at a fixed voltage. It uses the OEM regulator, and modifies the charging curve. On a warm day with a fully charged battery, you may see .5 volts above stock. Fixed voltage charging is the wrong way to treat any battery. You might want to take the time to learn more about VRLA batteries before you condemn any charging above 14.9 volts. There is substantial research to prove that some VRLA batteries respond very well to charging voltages as high as 16.5 volts - and a certain ammount of overcharge as well. I have posted this link before, but it bears repeating: NREL Testing of Optima Batteries The National Renewable Energy Laboratory (NREL) is a government research agency located in Colorado. They spent a pile of tax dollars proving just how good current VRLA batteries really are. That link is a 17 page pdf published by an independent, government laboratory - not a battery manufacturer. 'Link Quote missinglinkaudio The United States Marine Corps. When it absolutely, positively has to be destroyed overnight - even if "it" belongs to the base commander... Link to comment Share on other sites More sharing options...
missinglink Posted June 24, 2008 Report Share Posted June 24, 2008 I totally agree, and this is one of the reasons i stopped looking at the MLA module. I'll wait and see over time how some of the people who bought thems stuff goes. Well since we DO NOT over ride the alts control functions ,and after start when alt warms up you will see it stabilize around 14.8v I guess .1 volt is just too close for comfort to some. Next time some one talks to a battery manuf. When you ask about voltage acceptance ask them the TRUE question. It is not a constant 15v our module fluctuates with battery fullness and alternator temp compensation between 14.8v and 15.1v. PART two ask them which is worse on their batteries charging .2volts higher than the 14.9v or dropping to 11volts cause your shit cant keep up. Please let me know this answer I know the answer but apparently we now nothing even tho I run mine @ 15.8v/16.2v for the last 9months and they still hold @ 13.3v well over any safety warnings. ALL companies do not say the very highest max before damage they leave some head room I'm sure they leave more than .2 volts for (burn out , dry out , explosion ,or Hiroshima type catastrophe) sorry got a little wild . Look at the FI BTL thats rated for 2000 watts RMS, but people (Meade) put over 4000 watts per sub no problems huh why is this you say. Scott is allowing for the stupidity factor. Its just companies protecting them selves if you ask the question right I bet you will get more accurate information back. Plain and simple if they don't now its safer to so no!!!! I guess we will post the battery in brads truck. Its a 10year old auto zone shelf battery and has been charging @ 15+ volts for over 4yrs and still holds a 12.8/12.9v resting charge. Please keep us in the loop on this question. Sorry If I'm sounding pissy cause I am a little MLA Quote missinglinkaudio The United States Marine Corps. When it absolutely, positively has to be destroyed overnight - even if "it" belongs to the base commander... Link to comment Share on other sites More sharing options...
missinglink Posted June 24, 2008 Report Share Posted June 24, 2008 Accordman: I see you promote AA ,Scott is an awsome guy to know and personal friend. Next time you talk to him ask him his thoughts on the module he backs us 100%. Not to mention we did all the testing to my hummer at his shop between orders.lol He helped us with module set points and design as well. Accurate info and testimonials are the best for any product we just happen to supply both. Please ask us of your concerns we would like to know and love to help. Steve's had his for over 3 months now and its 15.3vcold 14.7v hot. Any ? anytime, Chris@MLA Quote missinglinkaudio The United States Marine Corps. When it absolutely, positively has to be destroyed overnight - even if "it" belongs to the base commander... Link to comment Share on other sites More sharing options...
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