Second Battery Sizing

[kamizake 0]

I'm running two 1200w amps in my Ram1500 to power two 12s and a front stage. I was having power issues so I swapped out my stock battery for an xs power D6500 (biggest I could fit), upgraded the alt to a singer 270amp, upgraded all wiring to 0ga, and put in a big 3 kit. That being said, on full tilt every so often I'll lose my components as the battery can't keep up when it slams for a few minutes.

I'm building a bigger box for the 12s I've got, so while I'm at it I'm going to have my builder make room for an additional battery in the cab (it's a quad cab, so not a huge amount of space back there). The installer told me he'll be putting an isolator in as well.

Here's my question though. Do I need that second Battery to be able to handle the whole system (ie, a d2700 with enough amp hrs) or will any sized battery work to support where the D6500 can't keep up?

Space is an issue, otherwise the choice would be easy for a 31 sized batt. I just want to make sure I don't put something in that won't be able to support or make a difference.

Thanks for the help.

[95Honda 486]

Honestly, I am surprised a 270 amp alt and stout battery cannot keep up with a pair of any 1200 watt amplifiers, especially since you upgraded the wiring...

 

I would seriously check to see if everything is OK with your current charging/wiring system before adding another battery...  Almost sounds like the alternator isn't doing what it is spec'd out to do...

[95Honda 486]

Also, when you say "Loose my components"  is the amp actually shutting off?

[kamizake 0]

Its only happened while I've been driving so I couldn't watch the amp, but my components cut out completely but the subs keep going. Used to happen constantly before I upgraded the wiring and alt, but in the four months since the upgrade I've had it happen once. My suspicion is that I pushed out too hard for too long. Regular daily use, never a problem. Just want to make sure it can better take abuse every once in a while.

[95Honda 486]

I would check and see what the DC voltage is at the INPUT of the component amp while your sub amp is going full tilt.  If it is really low, check at the battery and make sure you do not have excess loss in the DC power system somewhere before it gets to your component amp...

 

If the voltage is plain dropping really low everywhere then I would try and find out why...

[95Honda 486]

Also, your component amp may be going into protect for other reasons such as heat, impedance, DC offset, etc...  This is why you need to check to be sure it is/is not getting sufficient DC voltage...

[kamizake 0]

So you think it's possible the amp just isn't set right?

[95Honda 486]

I have no idea, but like I said, if it were me, I would isolate the variables starting with seeing what the voltage is at the DC input of your component amp...