__d_a_v_i_d__ Posted March 4, 2012 Report Share Posted March 4, 2012 AH tell you alot when you use the right calculations my friend. If you wanted to calculate how long you could keep your lights on. Exactly . Ah is hours . For how long ... Our systems are quick discharges and you cannot calculate it by ah, I'm on mobile but xs power Kyle I think it was made a post that ah is useless to measuare when it comes to systems Chevy Impala Shocker Sigs / TC Sounds 12s Sundown NS-1 | SAX 100.4 Sundown Neos | Dayton Audio Neos ETCCC ETCCC ETCCC My YouTube ---- Subcribe!! Link to comment Share on other sites More sharing options...
Bakerman Posted March 4, 2012 Author Report Share Posted March 4, 2012 Like I said, i calculated at worse case scenario at batts being 10.5v. So, a good amp is around 80% efficient. Add all my amps rated power, and you end up with 9240 rated watts from my amps. You devide this by 80% to get the input power required to produce the total 9240 watts, and you get a calculation of 11550 watts of input needed to produce the 9240 rated watts from the amps. Now, to change this to voltage required, you divide your required input wattage by your battery voltage (10.5v for worse case, and 14.4v for worse case). So, 11550w / 10.5v = 1100a. Now you calculate the available amperage from your alt. A top end usage car will use around 50% of the stock alt. So, my stock alt is a 110a alt, so therefore at high demand, my vehicle will use around 55a. Considering I now have a 300a alt, that leaves me with a round estimate of 245a from my HO Alt to power my amps. So before we figured that you need a total of 1100a to power my system efficiently at worse case scenario of 10.5v. 245a is available from my alt, so I subtract this from the total required. 1100a - 245a = 855a still needed to power my amps. So now I know that I need a batt or group of batteries with a total availabe power rating of 855aH to efficiently power my system at the lowest voltage possible. Now that I go back and configure, I was a little off from my earlier calculation of 1000, but even at 855aH, it is still overkill, b/c a good system should never get to 10.5v. Just wanted to let you know how I figured this calculation. Link to comment Share on other sites More sharing options...
Bakerman Posted March 4, 2012 Author Report Share Posted March 4, 2012 Just because you don't use AH directly in figuring power for systems, doesn't mean you CANT use it. Its all basic algebra, switching things around and converting them. Link to comment Share on other sites More sharing options...
01ExSport Posted March 4, 2012 Report Share Posted March 4, 2012 Maybe I'm a noob when it comes to electrical demands, but even with a battery bank like that, if you play full tilt long enough, you'll eventually drop lower. Since your batteries only serve as a reserve for your alt to charge. But I feel for ya man, Got a 4.0 Explorer and what I'd do for dual alts......(without giving up my A/C!) Link to comment Share on other sites More sharing options...
CJ18 Posted March 4, 2012 Report Share Posted March 4, 2012 So by your calculations, you should need 8 XS D3100s(110ah) along with your 300a alt to power your 4 AQ2200s? Are you truly going to see 8-10000w from your amps? Probably not once you consider rise and potential voltage drop. I was able to power 2 Powerbass XTA 5000s in a friends Expedition with 1 350a alt and 3 D3100s and only had voltage drop to 12.8v from 14.8 at full tilt. You have to consider the quality of battery also and not just ah rating. If you go buy yellow tops or just random Auto Zone batteries, then yeah maybe your calculations give you a decent idea about how many of them you will need, but those types of batteries are not designed for the type of abuse that an audio system will put them through. 4 D3100s along with a 300a alt will be more than sufficient for what you are wanting to run. If you want to talk about price of the XS batteries compared to others, think about the how long normal batteries will last before you have to replace them vs the life that you will get from the XS Batteries. Link to comment Share on other sites More sharing options...
TeamHT Posted March 4, 2012 Report Share Posted March 4, 2012 Sigh. Well, when you know you just know, huh? Tell me...does this smell like chloroform to you? Link to comment Share on other sites More sharing options...
mwjustic Posted March 13, 2012 Report Share Posted March 13, 2012 Im just going to add on to this post since I have the same question. Im only running one xtx5000.1 (2500 @ 1 ohm) stock alt stock battery. 1/0 big 3 next available chance. I want a .ew bat under the hood and one in the back. Whats a good combo? A xs d3100 in ths back and the same up front? I am completly new to higher end game of electrical. 2005 ford explorer xlt limited 4x4 2 xs power d3400s 2 runs of shca mid/ highs- infinity 6x8 3 ways 2 18 ssa icons 2 aq 1200.1 @ 2 ohms 10 cubes tuned to 36 hrz Link to comment Share on other sites More sharing options...
audiofanaticz Posted March 13, 2012 Report Share Posted March 13, 2012 So umm... If your calculations are so correct, and you say that AH means everything for a battery (which it dont). Why are you making this thread asking for help??? When the people with the correct knowledge are trying to teach you something and you are just blowing them off saying they are wrong... Thread locked.. You can lead a horse to water, but you cant force it to drink. Link to comment Share on other sites More sharing options...
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