Battery or not?

[Chybulo]

Hi there. I just got a system installed and was wondering if I needed a audio battery to replace my OEM battery. I was instructed not to blast the speakers yet till I had 7-8 hrs. of continuous playing to break-in my bandpass. Therefore my lights haven't dim yet. But I don't want to damage my amps or subs by not supplying enough voltage. My Amps total 1,400watts RMS. I have 2012 Legacy. My alternator amperage output is 110. My question is do I need a dedicated audio battery or my OEM battery will work just fine? Secondly if I do need a replacement is there a recommendation? Thanks for reading.

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[bigmizzle99]

Since nothing has happened yet, no, you don't (yet!) Lets do the math.

1400 W at approx 85% efficiency (just guessing, the Alpine might be higher as it's Class D) = 1647 Watts at full tilt

1647 Watts / 13.9 volts = 118.5 Amps required to get you to full tilt

at 110 amp alt, lets say there is 40% available for audio = 44 amps

118.5 Amps - 44 amps = 74.5 Amps (deficit) So, the battery needs to supply the rest. The stock battery will supply some of this, but probably not all. After you live with it and play it and monitor your voltage, then decide if you want a new battery.

Go with XS Power battery under the hood.

 

[negolien]

From what I have understood the "audio batteries" are more about being able to mount them at weird angle and not having spills. Except for the different sizes of batteries there is no benefit besides that.. i.e if you get a humongous deep cell yes it will supply more power but if you get the same size as the stock you won't.

 

[bigmizzle99]

Don't forget about all the real advantages of the technology

AGM has very low internal resistance, is capable to deliver high currents on demand and offers a relatively long service life, even when deep-cycled. AGM is maintenance free, provides good electrical reliability and is lighter than the flooded lead acid type. It stands up well to low temperatures and has a low self-discharge. The leading advantages are a charge that is up to five times faster than the flooded version, and the ability to deep cycle. AGM offers a depth-of-discharge of 80 percent; the flooded, on the other hand, is specified at 50 percent DoD to attain the same cycle life

 

[bumpasauras 10+ year member]

At that current draw you could get away with no batt ...

What I would do is add an additional batt in the trunk. Remember that lead acid batteries emit toxic fumes so you "should" go with a sealed battery such as a yellow topp, xs, or kenetic. If nothing else adding a second batt in the trunk allows you to run very short power and ground leads which is much more efficient at transferring current to your amp. When you get down to it adding a batt is a cheap way to make sure you are getting all the current to the amp that it needs, especially when you are marginal on your alt output.

So yes I would add a batt in the trunk....is it mandatory no, but it will help.