choosing a battery for under the hood.

I'm looking for a battery for under the hood, for everyday starting. Is there a big benefit to buying one of these expensive car audio batteries for that purpose as opposed to a cheap Wal-Mart battery?

I tried to do some homework, searched various car battery threads on different websites, but didn't find anything that flat out answered my question. I tried to read up on the specs of these different batteries (Kinetik, Stinger, Optima, etc), but don't fully grasp what all the different things mean, nor have I found a website or information that really tells pros and cons to all the different options.I've read that I don't want a deep cycle battery. I understand they're more or slow discharges, and recharging, and are not good for starting your car. So a YellowTop wouldn't be a good choice, but the RedTop would, yet doing a search on Optima's website the only battery that shows available for my car is the YellowTop, same with the local O'Reilly Auto Parts' website (shows only the YellowTop when I search my car's make & model, not the Red).I looked on Stinger's website, they state their batteries are dry cell (AGM technology), is that the same as deep cycle?  It also states their batteries are a higher quality than Optima, whether you're using it for a secondary battery or for primary engine start source power.  Not that I necessarily believe that, obviously a company will say what they need to, to sell.

So I'm still not sure what my best bet is here, I'm still poking around, trying to read up. Maybe somebody can shed some light or advice on the topic.  Maybe the only thing I need is a cheap Wal-Mart EverStart?  I understand that any battery will start my car, but if the benefits to one of these more expensive batteries are that much greater, I much rather go that rout.

I'm not running anything too crazy as far as a stereo, 6 component speakers powered by an Orion amp, along 2 10" Kicker L7's powered by an Orion amp as well. I don't mind spending more for a battery, as long as it's worth it & I'm not over-spending just because some advertisement looks good. Also, in case it's relevant, I drive a 2000 Acura Integra LS. And I live in a region that gets very cold in the winter.  I'm not sure if the deep cycles are not very friendly in the arctic cold.Anybody with any information that can help, I very much appreciate your time.

I congratulate you on your research, AND realising that deep cycle and high discharge (rate for cranking) are two different things requiring either if the two construction topologies (thick else much surface area for plates etc).    Of course, AGMs have high discharge/cranking currents owing to their nature... ("Real" AGM manufacturers rarely if ever quote cranking currents - but I'll get to that later...) To answer your question - NO - do not by a fancy "audio" battery. What you want is something with the cranking capacity that you need - I'd assume a few hundred CCA in your case. CCA is COLD Cranking Amperage where cold means 0°F (-18°C; CA is Cranking Amps at 32°F (0°C). The colder the battery, the less its capacity etc... FWIW - I converted from a normal starter to a reduction (geared) starter which almost halved my cranking current from >250A to ~140A. Futhermore, the reduction still cranks at 5.2V (at battery) whereas standard is effectively dead at probably 8V. However I suspect yo may already have a reduction (not uncommon in Toyota and some Hondas).    You probably know all the above already... As to AGM aka Recombination aka VRLA (Valve Regulated Lead Acid)... It is still a Lead Acid battery but is a subset of Sealed Lead Acid (SLA) batteries (depending on definitions!! ag - is Gel Cel an SLA? IMO, yes.). However, instead of flooded/wet liquid acid, or gel acid, it is "dry". It's acid is in gauze wrapped around the lead plates. This construction means it is leak proof and that it can be mounted in any position (often except for one - typically upside-down - but that is due to construction issues - ie, the plates fall out.). It also means LOW internal resistance... often called (or confused with?) ESR = Equivalent Series Resistance. AGM ESR's are typically HALF that of equivalent sized wet cells. Therefore AGMs typically have twice the short circuit current of wet cells. And therefore higher cranking currents etc. In other aspects they are now different - ie, AH is still AH. EXCEPT that AGMs will not tolerate over charging (eg, above 14.4V) because they have no liquid to boil off and hence liberate hydrogen gas, and heat up and go into a thermal runaway cycles.... And they do not like being left discharged for long.... The lower the voltage you discharge to, the quicker you need to recharge them. And strictly speaking, they should also be current limited... (Again, nothing to boil - but that is usually only a problem after a deep discharge.) If you cannot get a "normal" battery with the CCA required, then an AGM may be required. I theory, the same size should give (up to) twice the cranking current - but whether that applies at real low temperatures....? But considering that AGMs cost 2 to 5 times more than normal flooded,; that they are not suited to cranking (by construction - it is only their low ESR that provide cranking currents); and generally do not last as long in stressful automotive situations, I'd stick to flooded. If it was internally mounted, or subject to long inter-start periods (like collector cars that are run once a year and have no on-board alarms) etc, then AGM is the solution. That's my wordsworth. You will see lots of claims by AGM manufacturers. In general they are NOT suited to cranking, but provide good cranking current due to low internal resistance. And times change. Once perhaps I would have considered the "big Oh's", but one went bad some years back (though allegedly come good...). Despite me thinking otherwise (due to their marketing spiel), it seems Kinetik are good. Locally (Australia) I have been recommended Deka (and not the Os) and River-something. But I only have experience with telco-grade Yuasa & Gates (now Hawker?) AGMs (and man! what experiences!!!!) FYI - I just retired two 8 year old floodeds that cost $85 and have seen years of abuse, bad flattenings etc. I am now using a 10 year old AGM battery - but that's an AGM for high-discharge UPS use, and I think they cost around $400-$500 each. I gave one to my brother 5 years ago as an emergency cranker. It turns out he has been using it as his only battery for nearly 3 years... Alas, my partner awaits...