AGM Batteries

Yes, switched out my 8-d's for AGM. I was getting about a 2 year life with the flooded cell batteries, the AGM's are supposed to last 4-5 years. Just had to change the setting on the battery charger (pro mariner) for those battery banks.
 
I just switched out my Gp 31 bow thrusters. I bought from Sam's Club. Their batteries are made by the same manufacturer (East Penn) as West Marine and some others but were about $100/ea less than WM retail. You may or may not need to change anything on the charger: AGM's typically charge the same as wet cells but some newer chargers do have an AGM setting that's just a little different.
 
I've got Optima Blue Top Grp 31 AGM's on the 410 and Sears PM1 Marine AGM's on the 340. Great batteries. I've put an AGM in the Waverunner and one in my XLR. No problems and long life...
 
I think I have 3.5 years on my Diehard Platinums. I have 6 group 31's and I love them.
 
alnav said:
I just switched out my Gp 31 bow thrusters. I bought from Sam's Club. Their batteries are made by the same manufacturer (East Penn) as West Marine and some others but were about $100/ea less than WM retail. You may or may not need to change anything on the charger: AGM's typically charge the same as wet cells but some newer chargers do have an AGM setting that's just a little different.
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What SAMs did you get group 31 agms at? Do you have the part numbers? I looked several times at my local SAMs and they didn't have any.
 
I have 6 years on my Lifeline 8D AGMs this season.
 
I am curious why some folks batteries last forever and some don't seem to last at all.

I have 2007 year batteries in my 320DA. I'm not sure of the brand, but they are just regular old wet cell batteries. My mechanic hydrometer tested them this week and they came out perfect, but a little low on water so he topped them up. My boat admittedly spends most of its time on shorepower on the dock, maybe the battery charger that came with the boat is just that good?

I have to get the brand next time I am down there, because I will certainly buy them again, assuming they ever die on me.
 
On my 3rd year with Optima yellow tops, Work great. other than the top post seem really weak as in they move around when tightening them, I might switch to the side post of I have an issue.

LK
 
Turtlesboat said:
5 years on my AGM's so far.
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Have you had that boat for five years? Time flies!

I had put six Optima AGMs in the 2007 44DB after three years of constantly filling and checking the flooded cells. I can't report that performance was noticeably better, but I did love not having to futz with them.
 
In my experience the AGMs last longer and obviously are a lot easier to maintain (no checking the levels, etc.). They can also take more abuse, are sealed against fumes and will not leak (acid) if broken. I've read that they can be also be recharged at a lower voltage and accept more current and I remember reading (although I've never done this) they can be mounted about any way, including on their sides. In my case, I use them for everything possible - my house batteries, thruster batteries, jet ski, etc. Each time I have bought a boat I've replaced everything with AGMs and have yet to keep a boat long enough to have to replace a set (this is probably more of an indication that I need to stop trading boats than a statement about AGMs longevity!).
 
So it sounds like AGMs are the way to go.

Any specific brands to look for (or stay away from) other than lifeline or optima?

edit:

And while I'm at it how about the best place/price to purchase? I need to get me some 8D's
 
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mbates50 said:
Anyone switched out to these types?
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For the OP, I would question how do you use your boat? Let’s face it an AGM battery or two is a significant upgrade to the standard wet cell battery in price. That said I upgraded mine several seasons ago to AGM’s but my justification for doing so was time spent on battery. What I mean by that is how much time do you actually spend on battery power? Do you anchor out for the night with appliances on, radio amp cranked up…? Anything else that would be drawing the battery down? If so, then an AGM battery might be the best selection for you, and mainly because it will function as a deep cycle battery, as well as performs like a starting battery. If you don’t use a lot of your battery reserve while out on your daily outings, then a AGM might be a bit of an over kill and not worth the extra money.

With all that being said I am personally a big fan of the AGM. I have four group 31 Sears Die Hard AGM’s in my boat. But you can buy almost 3 wet cell batteries for one AGM, so if you don’t really need it, well that is your call.

There are many threads on batteries here, which you may or may not have already viewed, understanding the difference in battery types should be key to your decision.
 
I have the sears Platinum group 31. Im going on 5 years with only one failure ( out of 6 )
the CCA's are hard to match !
Rob
 
Dsybok said:
I am curious why some folks batteries last forever and some don't seem to last at all.

I have 2007 year batteries in my 320DA. I'm not sure of the brand, but they are just regular old wet cell batteries. My mechanic hydrometer tested them this week and they came out perfect, but a little low on water so he topped them up. My boat admittedly spends most of its time on shorepower on the dock, maybe the battery charger that came with the boat is just that good?

I have to get the brand next time I am down there, because I will certainly buy them again, assuming they ever die on me.
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I think the bolded part is your answer. Almost every weekend during season we're out, and when we come back to the dock and plug in, my house bank gives off a sigh of relief. I'm currently running 2 6v wet cells, and by Sunday night they're getting low. I'm running radio, lights, 2 fridges and whatever is plugged in to be charged.
 
I replaced all of my batteries with Sears Platinum AGMs, I had one failure(in month 33) and took it back to Sears, they replaced it no questions asked. These batteries have 36 month FULL replacement.
 
My boat was delivered with AGMs. They did not fail, but I replaced them on the advice of my tech two years ago because the alternators on my boat are more expensive than new batteries. If the new ones last as long, that's good value.
 
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