You couldnt be further from the definition of wrong.

Deep cycle batteries are what is optimal for stereo applications. An alternator does not run your stereo. Sure it will, if you want to keep putting strain on it. Batteries are there so your alternator doesnt have to keep working at its hardest 24/7

 

Johnson controls makes most of the batteries on the market today, some differences in quality and warranty. They make Duralast (autozone), Die Hard (Sears), Everstart (Walmart), Kirkland (Costco), Interstate, and Motorcraft (Ford). They also make Optima Batteries.

 

oem mazda miata battery

 

interstate.

 

I've used Optimas in 3 different cars over the past 8-10yrs and have zero complaints. All three have lasted longer than I anticipated (all three still work to this day). It's the only battery I'd consider buying for pretty much any of my cars.

With that said, I'm using a pC680 in my DA since it's a track car and I wanted something small and light. I've had some minor issues with it, but I'm assuming they would have happened with any small battery - just something you have to deal with, especially on a car that spends a LOT of time sitting w/o being started. (and yes I know you can get similar batteries for cheaper, I opted to pay more so I could get the battery tray which fits it perfectly opposed to making something for a different battery or ghetto-rigging something else)

 

non of those listed in the poll...ive been using these
http://www.amazon.com/Brand-New-Kine...047496&sr=1-19
http://www.amazon.com/Kinetik-HC800-...5047496&sr=1-4
http://www.kinetikaudio.com/2009/pro...p?P=KHC800&C=1
http://www.kinetikaudio.com/2009/pro...p?P=KHC600&C=1
^^^ this battery is smaller and lighter then the pc680 from odyssey and has much more power...20Ah vs only 17Ah from odyssey and its cheaper.
pound for pound these things put out more amperage then any other battery ive tested

 

bought an Optima Yellow top from NAPA with a 3 Year warrenty

 

You didnt add interstate to the list... Its used by alot of auto manufacturers as oem batteries. Definately one of the best.

 

AC Delco 51R6YR

 

I have used the optima yellow top batteries for 7 years and i also have 4amps,digital signal process,head unit,subs,and a **** load of lights throughout with no problems.I like them because of the reserve time as well as mounting possibilities.Right now i have it mounted under my left front fender/bumper region.Good luck.