Let's talk marine batteries

[Mr. Sandman]

What do you like and why?

( need to re-do everything this spring) I was thinking of two lifeline 8D's for the house load and 1 group 31 for the starting battery.

I have been leaning to AGM's because they are sealed and will work in any orientation. But I had an AGM go bad on my other boat for some reason after a deep discharge. (pump left on for a few days) and it would not hold the charge very long after. I replaced it with a new one and all was good again.

What do you like and why?

[islander]

Jim, I have great results with the AGM, one of there biggest plus is the ability to go way down and bounce back. You must have had a lemon. Good luck with the new ride,,,looks really nice.

[wrench]

Those AGM's you had trouble with were not Optima's were they?

[Mr. Sandman]

No, they were something I purchased from west marine. (Sea Volt brand I think). Over all they were fine for a couple of years but that one time I really discharged it to zero (by accident) the house battery was kaput after that. I bought it back and they tested it, and the machine just said "error" and it was a few weeks after the warranty expired (figures), they were group 27's. I replaced both of them (and sold them with the boat) and I still have the other old one and it is still very strong. One thing I learned that the output from most outboards alternators is not that great unless your running 5000rpm.

I am boning up on my marine electrical. I see a lot of things I want to change/add. I want to change the way the battery wiring /switches are laid out. I don't see the logic in the current layout. If I get in over my head I will bring it to an expert but I think I can straighten it out. I like doing it myself if I can this way I understand the inner workings if (when) something breaks.

A buddy told me once...in general buy batteries by weight: heavier= better. I like the theory behind AGM's I think they make the best sense for boats. However in the past there were two types of batteries: Deep Cycle and Starting. I understand they differences but the new AGMS are " Dual use", Both deep cycle and starting. There must be some advantage one way or the other I would think. Is a classic "starting battery" better than a "dual use" battery for starting and engine?

[RIROCKHOUND]

Originally Posted by Mr. Sandman

One thing I learned that the output from most outboards alternators is not that great unless your running 5000rpm.

Isn't that the truth! found that out more than once working w/ the r/v.

We killed one of our group 24 AGM SeaVolts after a severe draw-down too Jim, so it does happen, whatever they do say.

[wrench]

Jim,
Check out the Marine AGM batteries from Sears,these are made by Odessey for Sears and have heard good thing about them and the odessey's,but only come the largest is a group 31 I believe.

DieHard Marine Battery, Platinum PM-1 - Group Size 31M (with exchange)

Mike

[MakoMike]

I've been running 4D size seavolts for three years now. No problems except that I did ruin one by running it to zero. They can't take being run down that far and bounce back. I have one for each engine and one for the electronics/emergency.

[quick decision]

I have two interstate that seem to work ok. Did have a dead battery a couple of times. Wasn't the batterys fault. I had them tested at the ZONE and seemed fine. I will charge them up this winter and use them again

[angler management]

maybe a dumb question, but what's "AGM"?

I have 2 batteries that will now die if left sit for a couple of weeks. Since I like to go off shore, I'm dumping them next spring for a piece of mind.

Look at the Sears link "Wrench" put up,,, $250 Each? Holly S%$#

I knew they where gona cost me, but never would have guessed that.

Maybe guys on those boats with bed sheets stuck to a pole have it right.

Never mind, back to reality,, small price to pay to go anywhere the wind does not blow.

[gf2020]

Originally Posted by angler management

maybe a dumb question, but what's "AGM"?

Absorbed Glass Mat

The Odyssey 34M-PC1500 is the top dog in AGM batteries.