Best Deep-Cycle Battery
 

What is the best battery for an after market sound system?

depends
what type of aftermarket sound system are you running? dual subwoofers? Power cap?

I originally installed an Optima Yellow Top on mine but after that died a few years later I then had terrible luck getting a quality yellow top to work. (went through at least 5 in a year). I think others have reported that ever since Optima sold the company, their QC has suffered. Or maybe it was just me? :dunno:

I now run a bosch battery (and have for 5 years) and it's worked great.

Just pick a an AGM with the best warranty unless you are running some crazy audio setup. The Odyssey in my RX-8 just doed a month after the 3 year warranty but considering it is an undersized battery for the car and sits a lot it's not bad since most normal batteries only last about 3 years in South Texas. I too went thru a couple of Optimas, they suck.

I put a H8 AGM from Advance Auto in my BMW 335i and it has held up great. Plus Advance always has great coupon codes so I saved $50.00 ordering online and picking up in the store.

i have two 12 inch rockfords, and yeah i just had a optima yellow top and was not satisfied one bit!

My experience with systems depends on how much power you are putting out. IMHO, the best thing you can do is upgrade the big 3 first, to the amp run a 0 gauge for power and 1 for ground and keep it short, but with a really good connection. If you are running 1500W peak or less, a cap will suffice, i have a 1.5F in mine, but I'd say a 3F would be better of course.
Running larger gauge wires allows for better power flow, for charging and power draw, the cap helps for when bass kicks in, drawing 20% to 40% more power, preventing the batteries from quick discharging, which will eventually kill it regardless of quality.

If you run multiple amps, so 3KW or more, consider the above but skip the cap, upgrade your alternator and install a dual battery system. The big 3 is more important than the battery you use.

Been using a Bosch AGM in my 06 BMW 330xi and it has been nothing but excellent! I highly recommend their batteries. I have not been pleased one bit with the quality of Optima batteries in the last 5 years. They used to be the best but now I question their longevity.

What model are you guys using with the Bosch AGM?

The RX-8 uses a Group 35 battery.