look all that stuff is to run for 5 minutes in a sond off, competition stuff is only to make the time limit for sound off readings not for continous use... over priced for what they do.....and if you have to run farad caps then you power supplies in the amp are ****...look i only run the old 1980's stuff. it is relitively inexpensive compared to the new stuff...I can pic up a 600 watt amp and just install and play ..if I buy a 600 watt amp today it has a crossover and i have to run a farad or mmore cap at an added expense of 100 dollars...face it todays equiptment is for the do it your selfer and has to have circuit overload **** all over it so that the idiots dont bring it back...all this battery crap is just that...
If you want a great battery look into buying golf cart batteries they are inexpensive and made to perform...

Not exactly. I can use mine for 2 weekends straight without a charge. They're made for reserve time also.

Caps don't do anything but store energy for short bursts. They're pointless in boats, and don't really do much in a car either.

I don't know what the point to all your ramblings are up there, but you still haven't answered my question. You're way off though, and obviously don't know what you're talking about. You put "Stinger sucks" in the thread title, and then talk about how you're stuck in the 80's with amps that require external crossovers, aka noise magnets.

And people wonder why I don't ussually get involved in these threads any more

It's an endless battle.

I was hoping to get an answer but theres 7 pages of arguments and no one has any recomendations of which battery is better. I am looking at optima kinetik stinger lifeline and shuriken to power a sorta basic 2 amp jl system I would like maybe three or four batterys to power this thing all day if need to. My experiences have only been with 3 deep cycle wet batterys and 3 amps and max usage I could get was roughly 4-6 hours. Please could someone advise on which would suit me best? Reason I want a completely sealed gel battery is they will most likely be mounted in cabin. Thanks

Amen.

+1 on Kinetic Batteries - They are Superior to most everything out there. I have (2) 2000 AMP batteries and I have 2/1000 watt amps and 1/800 watt amp. Ive tried to kill these things and cant do it! they are about $325 (i think) a piece but worth it

Figure out how many Amp hours you draw and you can then size the battery bank based on what runtime you want. Since you are looking at all AGM batteries anyway you may just look to the manufacturer that has the right fitment for your boat. I bet your biggest challenge may be cost and availability with the batteries you are looking at.....

Here is a battery size calculator that may help:

http://www.lifelinebatteries.com/marinesizing.php

A friend who is an installer suggested using 4 Shuriken skbt60's Hes done alot of marine installs and replaced a few optima systems with these and says they are far superior.