Right Starter battery for a GT40

I bought a 2001'SN and it came with 2 brand new deep cycle batteries so I need to at least replace one for a starter battery. Been looking around the forum for recommendations including the FAQ to no avail.

The battery in the battery whole built in the floor is too tall to put the lid on. Is a group 24 the right size? concerned that it might not be enough for a 5.8 HO.

Then what brands are recommended. Does not have to be the most expensive un less the most expensive is really worth it. I don't really listen to much music w/o the engine running and I only have a head unit (no amps).

You need a group 65 starting battery if you want the lid to close.

Just get the biggest CCA you can. It isn't 100% necessary to go that high but I believe it does make them last a bit longer if they are operating at less than their recommended work load etc.

Guess it isn't as important here as you will probably be running stereo stuff off the deep cycle.

If it doesn't have some crazy sound system it's really useless to have 2 batteries let alone a deep cycle.

I have a 1000 CA group 65 and a 400W amp. I can run that set up for as long as I want as long as I fire it up once an hour and let it run for 5-10 minutes.

rrichr wrote: I bought a 2001'SN and it came with 2 brand new deep cycle batteries

Did the PO install them? Was it a "marina"!

phatsat67 wrote: Pete, dad had a Deka new and I adopted it when he bought a new battery for his rig. Same CA as my current battery and we collectively got around 8 years out of it not charging in the winters.

You didn't mention the CCA!

My two failures were Exide 1000 CCA's. I actually called Exide after number 2 and that's when I found out the internal support is sacrificed. The engineer told me that's how the high CCA's are done in all brands.

8122, The PO put the deep cycles in...

So you are saying not to go with the 1000 CCA's becuase of short life span becuase of design? OK

phatsat67 wrote: Optima are nowhere near worth the money. Most we see in here are bad and need replaced and we have the proper charger to recharge deeply discharged AGM batteries.

I gotta disagree with you on this one Zach.
I bought an optima for my boat before I left WI. In fact the sticker on it says Feb. '01. Ran it for ten years and replaced it because I thought it was the cause of low voltage messing up my starter. It was ten years old after all.
So I got another Optima. Didn't fix my starter issue but then neither did a rebuild. A new starter fixed that issue.

I bought the new Optima online and didn't have a core charge so the old one just sat on the garage floor for two years (on a rubber mat). I never touched it other than to move it out of my way when I cleaned the garage.
Then my truck battery went out so I grabbed the old Optima just for the hell of it and used it to jump start my truck much to my surprise. So I decided I might as well use it. It was way smaller than the OEM truck battery so I had to get my dremel and enlarge the terminal holes on the battery hold down cover so it would fit and it's been in there for a little over a year now working perfectly. It's now 14 years old.

I'll never hesitate to spend the money for an Optima again.

backfoot100 wrote: the old one just sat on the garage floor for two years (on a rubber mat).

Eddie,
Don't tell me you believe batteries still need to be stored on something to insulate them!! There was a time way back when the cases were basically coal tar and the scenario had merit. The case would absorb water moisture and then depending on the floor moisture would create a path to ground so the battery would discharge. That's not the case anymore due to the plastic cases.

backfoot100 wrote: phatsat67 wrote: Optima are nowhere near worth the money. Most we see in here are bad and need replaced and we have the proper charger to recharge deeply discharged AGM batteries. I gotta disagree with you on this one Zach. I bought an optima for my boat before I left WI. In fact the sticker on it says Feb. '01. Ran it for ten years and replaced it because I thought it was the cause of low voltage messing up my starter. It was ten years old after all. So I got another Optima. Didn't fix my starter issue but then neither did a rebuild. A new starter fixed that issue. I bought the new Optima online and didn't have a core charge so the old one just sat on the garage floor for two years (on a rubber mat). I never touched it other than to move it out of my way when I cleaned the garage. Then my truck battery went out so I grabbed the old Optima just for the hell of it and used it to jump start my truck much to my surprise. So I decided I might as well use it. It was way smaller than the OEM truck battery so I had to get my dremel and enlarge the terminal holes on the battery hold down cover so it would fit and it's been in there for a little over a year now working perfectly. It's now 14 years old. I'll never hesitate to spend the money for an Optima again.

Nice Eddie. I know people don't properly care for things very often and an AGM requires a little more attention keeping it at a full or near to full charge. We just see them bad a lot coming through here. Quality might have also been better 14 years ago before the brand was very popular and production costs and margins came into play.

Heck, I was only 13 years old when you bought that battery!! haha.

I just think if I can get 6-10 years out of a standard battery without special treatment then why would I throw down an extra 100-120 bucks for a battery that will probably last the same amount of time. It would eventually iron out of the optima lasted 5 more years but how much longer would that take in the scheme of things.

Steve you just got the kiss of death!

skutsch wrote: For what it is worth, my GT40 is powered by a Duralast 41-DL, it came with the boat, it is only 650 CA. but it is going on 10 years, I also do not charge it during the winter.

Steve,
You aren't doing anything wrong not charging it in the winter. I have NEVER charged any of mine plus, they all stay in the boats all winter without any issues. My X battery has to be at least 12 years old.

8122pbrainard wrote: backfoot100 wrote: the old one just sat on the garage floor for two years (on a rubber mat). Eddie, Don't tell me you believe batteries still need to be stored on something to insulate them!!

Naw Pete, I have a rubber mat laid out the width of my garage in front of the work bench so the concrete isn't so hard on these old knees. The battery just kept it from moving around. Now I have to keep a couple old warped rotors on it for the same purpose.

My Air Nautique had a Optima red top in it when I bought it. It's been a great battery. But mine is an older one, before they got bought out by Johnson Controls and the quality dropped. I will go back with a AGM, I don't want water bouncing around where the battery is located, at the front of the bow.

phatsat67 wrote: Steve you just got the kiss of death!

I suppose I should just go buy a new one right now, huh?

The day I drained 8+ quarts of oil out of my friends 351 PCM I noticed he had his battery in the house on a wood block, on newspaper, on carpet...