Interstate Batteries arnt the best but they are cheap and you can find replacements pretty much anywhere when on the road. I have ran Interstate's flat before with a 36v TM.

Optima or Cabelas AMG's are good bats if your want to spend the money. The ratings on Cabelas batteries are the best ive seen especially on the cranking batteries.

I have deka's in my boat now and wont ever own them again, I would say they are comparable to Interstate Batteries. If you dont fish big water and the TM isnt on 100 all day you should be fine, but I have ran them flat.

Trojan has lasted the longest from my experience and I'm not talking contraceptives.  LOL 

Optima blue tops - mine are 3 years old and still going strong!

I've been using the Wally World batteries and  I replace them every two years even though they are still good.  The heat, charge/discharge and rough boat rides are tough on lead acid batteries.  Personally I never expect to use the warranty so that part of the purchase is pretty much meaninless to me.  I want low price first and last.

Speaking of batteries, beside the obvious dead on water senario, when is a good time to get ready to change them out as far as voltage they are holding when fully charged..thanks

Reason I ask is I hear of guys batts have a charge @ 13.1...all four of mine show green lights and a charge of 12.8, when I take them off the charge and the sit they may drop to 12.6 in 24hrs or so..thanks in advance

 I can't reccomend batteries other than the walmart ones I have used for many years now, but I do know that with the heat we have had lately, everyone might check the fluid levels on them. no better way to kill a good battery than no water. I would wager 25% or greater would be low, and of those only half would admit it.

You can't go wrong with the wally world deepcycle. Had optima blue tops before I went to a 36 volt system and didn't like the fact that after two years one battery was dead. For the money I would have thought two years would be half the life. 

We sell Interstates.. And I am not saying they are the best batteries on the planet.. But they are good when properly maintained.. Lots of people think that batteries are like a sprinkler system.. Once you got one the work is done.. Not true in either case..

Check your water levels every two months, especially during heavy use periods.. Recharge your batteries as soon as possible when you get off the water. Long periods of storage while batteries are weak or low, is bad for them. So charge your batteries when you get home.. Not a week later before you head out again.

Some of these chargers they put in boats are a joke.. They might work well for a time.. But here's a rule of thumb.. If it is a two or three bank charger, and 1) it weighs less than five pounds.. It is probably a POS.. 2) If you buy one and it costs less than $100.. It is probably a POS. Most good chargers cost $200 or more..

We mess with batteries and chargers all the time. And my experience tells me that most battery problems are caused by the users.. Due to lack of maintenance. Some problems are caused by POS chargers that hang up and cook your battery to death.. Cheap automatic chargers are famous for this shit. And once you cook the water all the way out of one, you might as well shit can it.. It may come back a bit, but when you are counting on it it will croak..

My personal opinion is that the Trojan monster batteries are hard to beat.. I had some for four years and they were still bad ass.. But I changed them out anyway.. My Dad used one of them on the farm for three more years..

But I use Interstates now.. They have a hell of a Warranty at my store.. :-)
And I use the 29 series.. They're pretty awesome..

Best charger out there is the Dual Pro machine.. Although they may call it something else or your boat dealer may have it tagged for them.. That son of a bitch weighs fifty pounds and it works.. And their warranty is also the best I have seen..

I am sure there are those out there that have had trouble with all the shit I just recommended.. But this has been my experience..

+ 1

I use the Maxx 29 from Wally World for 75.00 each it is hard to beat.  I also have a routine that I do regularly.  Get home - put the boat in the garage, grab a Coors Light, wipe down the boat from the trip home, plug in the batteries and leave them plugged in until next trip.
 Sometimes I get the beer before I put her in the garage!    

Optima blue top all the way! I still have one yellow top going strong that it 6 years old! Yes 6 years. The blue top have a better warranty than the yellow top. I think the blue top are 2 year replacement. Have tried interstate and can get 3 years max. Other brands that are cheaper I only have 1 year of luck. My current blue top optima's are almost 2 years old.

Deka, held up fairly well. I am trying Continental right now and see if they are any good.

Go to an interstate dealer and ask for the POWER PATROL AGM.  Had some for 5 years. Never ran them down. They are used to run electric wheel chairs, so they hold a dang good charge.

David,

The Power Patrol series 29 (12V 100 Amp Hr) sale for $169.95

The Optima blue top (for comparison) sale for 267.95

I'm telling you, those Power Patrol put out the juice. If I ran my TM on the highest setting all day long, I could run for 2-3 days without recharging.  Like I said, I had them for 5 years, and would still have them, but sold them with the boat. The man that owns the boat now still has them on the boat. As soon as the continental TM batteries go bad on my new boat, I am going to replace them with the Power Patrol AGM's.

I broke down and spent the bucks on Optima's last year and have been very pleased with them. No issues at all.