batteries, how many, what kind?

 my new build will consist of 2 aq2200 strapped @ 1.4 ohms, 1 or 2 aq 90x4. 320 amp alt in the way. yellow top under the hood. big 3 in check. I'm looking at the XS power d3100. will one be enough for 5000+ RMS?Before you see the light, you must die!!

If you want to get 5kw from those amps you have to use 16v power... At 14.4v your limited to 4.6kw. The 1.4ohms your talking about is the DC resistance correct? Not the nominal impedance..This is what I do for FUN!

Get a normal battery under the hoodie & put the canary next to the amps. I presume you have a 350A alternator to keep up, else run lower powers and give enough time to recharge?

i meant total RMS with all 4 amps. the sub I'm looking at has duel .7 ohm coilsBefore you see the light, you must die!!

oldspark wrote: Get a normal battery under the hoodie & put the canary next to the amps. I presume you have a 350A alternator to keep up, else run lower powers and give enough time to recharge?

      i have a 320amp alt. on the wayBefore you see the light, you must die!!

oldspark wrote: Get a normal battery under the hoodie & put the canary next to the amps. I presume you have a 350A alternator to keep up, else run lower powers and give enough time to recharge?

      i have a 320amp alt. on the way. will the one yellow top out back be enough for the power i want to run?Before you see the light, you must die!!

You really need matching batteries... How old is the yellowtop? I can't remember the name or even the manufacter... but Carquest supposedly has some *NICE* AGM batteries for the price.2013 Kia Rio -90a alternator

DDX470HD GTO14001 GTO1014D (x3)

Big3 in 1/0G

1/0G to GTO14001

The batteries do not have to be matched is they are not permanently paralleled - ie, if they are only paralleled whilst charging or under (heavy) discharge. For the charging only situation, a charge-lamp controlled relay/contact system can be used. Otherwise a voltage sensor - eg; connect when above (say) 13.4V with time-off & time on-delays. If paralleled, keep in mind that that doubles the unreliability (failure rate) of the batteries (where the failure rate is for the battery self-collapsing). And if one battery fails, the other does too. And if paralleled, "matched" means same battery type & batch, same temperature, and diagonal load connection - eg: The greater the deviation from these conditions, the quicker the failure rate. (Paralleling matched batteries is an attempt to eliminate the runaway interactive demise behaviour - ie, charge differences leading to dragging down of the better battery. Then failure is merely(?!) dependent on the battery's normal MTBF etc... As to whether your yellow top is "big enough", how long do you want it to last? EG - with no charging @ 5kW, at 5kW load a 75-25 might last 5 minutes (though it is only spec'd to 40A for 1 hour - IOW - if your alternator is outputting its full 320A and you have a total load of 360A (total load is 4.6kW@12.7V), it will last 60 minutes.

Most people, when adding batteries to a high-amperage system like this, usually just parallel in som bigger batteries in th trunk etc... Most do not use isolators or anything. -I never understood why people mix-match battery types. I recommend using 2 matching batteries -one in the front, one in the rear. I feel that if your current yellowtop is not more than a couple of months old, you could go get another one. Otherwise, it looks like you'll be needing a matching set.2013 Kia Rio -90a alternator

DDX470HD GTO14001 GTO1014D (x3)

Big3 in 1/0G

1/0G to GTO14001

As I said, paralleling is bad - especially with AGM batteries. The risk of fire etc is there, but just the fact that if one battery fails, so do the rest unless you get to them quick enough. Ever seen the tears of someone that invested $700 in 2 AGMs, and because one failed (2 cells collapsed; presumably manufacturing defect), both batteries destroyed, his vehicle was close flames; $700 gone withing 3 months. (I LOL'd - I had warned him, and then I prevented its reoccurence with a $15 relay!) That was a engine bay and boot matched AGM from a reputable manufacturer (that also claim that paralleling is ok despite the warnings and finding of various battery groups).    Unless your idle time exceeds your charging time, do not parallel. Things might be fine for the first year or so, but.... As to being "matched" in the engine bay and boot - even ignoring the temperature differences - think about it. The AGM probably has an internal resistance of 2 -7 milli-Ohms. How does that compare to the total cable resistance between the +ve and ground/-ve terminals? If the latter is significant, then the diagonal connection with matched cables compensates. Then you only have the temperature issues to worry about. If cable resistances are insignificant, then fine - it is only the temperature difference and the "double unreliability" (half the MTBF once past the initial J-curve)) that has an impact. I'll ignore vibration and localised spikes (ie, cable impedance)... Last week I read another excerpt like.... "all (battery) failures were found to involve parallel batteries...". There is no question that an isolator is a profitable investment over the "normal lifespan" of the paralleled batteries. Until one of the batteries fails (or starts to), an isolator is a waste.     I shudder when I see even small "matched" AGMs paralleled in the boot (ie, a few 7AH AGMs etc). And whilst mismatched wet/flooded cells may not have the same thermal considerations - they just boil acid instead - they are more likely to fail.... My multi-battery summary for audio-type systems is generally akin to: - an AGM is unnecessary in the engine bay; keep the original else get a cranking AGM (unless perhaps 2 deep cycles paralleled for cranking) - localise high-current surges with an AGM mounted near the load (eg, amplifier in the boot) - the load's AGM to be deep-cycle or cranking to suit requirement (or both; whether paralleled or monoblock) - all paralleled batteries to be un-paralleled when not charging (except f.ex paralleled deep-cycle & cranking in boot where a low-volts cutout disconnects the cranker etc) There are exceptions to the above broad generalisations. And I haven't gone into specifics. I think that when isolation can be as cheap and simple as 2 circuit breakers and a relay ($20 upwards) which are usually required anyhow, why bother risking compromise? People go to the expense & trouble of bigger alternaors or parallel batteries.....