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Battery Brands

Jan 22, 2008
740
Hunter 340 Baytown TX
The three group 31 house batteries on my Hunter 340 are close to a decade old. Last half dozen day trips for races on the bay, the reefer and stereo have drained them enough to require switching to battery 2 to start the engine. A quick internet search shows about a half dozen brands of deep cycle group 31 batteries available. I know of one 340 that has gone to lithium batteries, I have no idea how many or what size I would need to match the capacity of my current house bank. And I'm really not ready to make that large of an investment for batteries.
But it will probably be just south of thousand bucks for three AGMS's. Anyone that has made a recent battery purchase, what brand did you pick and where did you buy them?
 
Feb 21, 2013
2,135
Hunter 46 Point Richmond, CA
Check with Crown (Alex Robledo (562) 404-1222) for low AGM battery prices. I am planning to replace ten (10) flooded batteries in a boat I am purchasing with 220 Ah deep cycle AGM batteries for $229 each delivered.

 
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Jan 11, 2014
7,104
Sabre 362 113 Fair Haven, NY
If you go the AGM route, it is essential that you are able to charge them appropriately and keep them at 100% SOC or they will die an early death.



I anticipate replacing my batteries next spring and I'm considering Firefly AGM batteries. These batteries are able to handle being at a Partial State of Charge for longer periods than other AGMs. That technology comes at a cost.

 
Dec 4, 2018
44
Balboa 27 Denver
Might want to mention whether they are 6 or 12 volt as a 6 volt 220 AH battery for that price is not as good as 12 volt.. AND a 220 AH 12 would be a heavy SOB.
 
Dec 4, 2018
44
Balboa 27 Denver
If you go the AGM route, it is essential that you are able to charge them appropriately and keep them at 100% SOC or they will die an early death.



I anticipate replacing my batteries next spring and I'm considering Firefly AGM batteries. These batteries are able to handle being at a Partial State of Charge for longer periods than other AGMs. That technology comes at a cost.

I have 3 Firefly 31's and am very very impressed with their performance. More like Lithiums than LA's. Go big or gohome..
 
Sep 25, 2008
6,037
Alden 50 Sarasota, Florida
Opinions vary (as you see from the comments thus far). The conventional wisdom is that flooded 6V batteries are the best value both in terms of $ and longevity.

Opinions also vary in terms of brand - most people don’t have experience with all brands of batteries so and judgment made can be dubious
 
Jan 22, 2008
740
Hunter 340 Baytown TX
Thanks for all the responses, more research to do. I will check on Firefly batteries.
More info, boat is docked at a marina with shore power. Batteries on constant charge when not sailing, by a “smart” charger.
D9A3B425-BA22-4B7B-B679-D70EE20A1802.jpeg
 
Jan 11, 2014
7,104
Sabre 362 113 Fair Haven, NY
Fireflys may be an answer for you. Since Fireflys can tolerate a lower PSOC you may be able to get away with only house batteries instead of 3. If I go with Fireflys next year I'll be replacing 4 6v GC batteries with 2 Group 31 Fireflys. Usable amp hours are almost identical.

Before jumping into the big bucks with Fireflys, read the manual. It can be downloaded at Ocean Planet Energy. Your charger may be a tad small for 2 batteries.

 
Jan 22, 2008
7,976
Beneteau 323 Annapolis MD
... Since you aren't tough on your batteries, your local Sam's Club can probably scratch that itch:

The reviews look pretty weak, but Duracell is a reputable brand..
I have 3 Durcell 31s, and they are outstanding for my B323, 3ym20. I won't bother buying any other brand.
 
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CarlN

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Jan 4, 2009
554
Ketch 55 Bristol, RI
Ten years? Just replace with the same - a good deep cycle flooded battery and be all set for another 10 years. Trojan makes a good flooded G31. So does Crown. Make sure you know who built the battery (it's easy to put a fancy brand label on some bargain bin battery from China).

The only reason to get AGM is if you plan to buy a huge new alternator so you can charge really fast. AGM's typically have shorter lives than flooded. Sometimes as little as one year if they are not kept fully charged.

I have Firefly's and love them - but I have 300 amps coming out of the alternators that has to go somewhere.
 
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Apr 8, 2010
1,529
Ericson Yachts Olson 34 Portland OR
If you want to spend the $ to be near the cutting edge of battery technology, more power to you (literally).
Having got a decade out of the present batteries, why change?

In our case, we converted from a pair of group 24 batteries to a pair of Trojan T-145+ golf cart batteries for our house bank -- which handles all running and starting loads -- decades ago. Last pair of the T-145+ batteries lasted 9 years, so I installed two new ones.

That said, we do have a spiral cell AGM battery living like an electrical hermit, under the aft berth, and we charge it and later test start the diesel with it a couple times a year.... works great.

Probably several "right" answers to this question, but it's interesting to read about other folks' solutions.
:)
 
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May 24, 2004
6,635
CC 30 South Florida
A three battery bank is just as good as the one weakest battery in the group. Load test them individually and if all three are weak just replace them but if instead you find there is one that is much weaker than the other two then you could gamble on just replacing the weak one. You can divide the banks the two in #1 switch position and the new one in #2 switch position so it can be isolated from the other two. When needed they could be combined.
 
Apr 14, 2009
730
Sabre 28 NH
The reviews look pretty weak, but Duracell is a reputable brand..
I've had good luck with their 6 volt GC batteries for my house bank. Haven't killed them yet & I'm on a mooring. Shore power doesn't exist, only solar.
 
Jan 11, 2014
7,104
Sabre 362 113 Fair Haven, NY
There are only a few major battery producers in the US, East Penn and Johnson are two. East Penn produces batteries under its own brand, Dekka and many other brands including NAPA. @Maine Sail keeps up to date on who is making what.

IIRC, Duracell 6V batteries were at one time made by East Penn.

Unfortunately, I can't give you any advice on knowing who made what. I know East Penn makes NAPA batteries because the guys at NAPA told me.
 
Jul 26, 2009
234
. . .
I have 3 Durcell 31s, and they are outstanding for my B323, 3ym20. I won't bother buying any other brand.
+1. Got 10 years out of 2 of those Duracell batteries as our house bank. Had to replace them this year but couldn't find the same battery locally. Ended up going with the NAPA/East Penn - time will tell.
 
Jan 19, 2010
868
Catalina 34 Casco Bay
I needed batteries. The only place open at the time was Sam's Club. They had Duracell Group 27 AGM marine batteries...
What a POOR choice I made. I used these 3 strictly for the house bank. The won't hold a charge beyond 12.4. They meter will show 13.4 to 14 v of charge going in. Discontinue the charge and they will indicate 12.4 ish.
Their deep discharge is less than desired.

MY MISTAKE....
 

NYSail

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Jan 6, 2006
2,644
Beneteau 423 Mt. Sinai, NY
I had 3 Duracell group 31 agm on last boat. At a slip always plugged in during week, away Friday to Sunday at anchor/ mooring. I sold the boat when they were 5 years old and still going strong. They are made by deka/ East penn and are reported to be an inferior Not true deep cycle agm as compared with lifeline.

I replaced agms on new boat with 4 Trojan 6v Flooded and love them so far.

good luck
Greg
 
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HMT2

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Mar 20, 2014
864
Hunter 31 828 Shoreacres, TX
Bill, for what it’s worth I replaced my batteries in 2018. I put in two series 31 130 ah each deep cycle and a series 24 start batt from Republic Batteries here in town for $350. I’ve been super happy for two years.

6130 Long Dr
Houston, TX 77087
(713) 645-2141
 
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Jan 22, 2008
740
Hunter 340 Baytown TX
Bill, for what it’s worth I replaced my batteries in 2018. I put in two series 31 130 ah each deep cycle and a series 24 start batt from Republic Batteries here in town for $350. I’ve been super happy for two years.
Thanks Mike, I will check them out. Their location is not real handy, but there are not a lot of other options and that price sounds pretty good. The batteries are not as old as I thought. I got them at Academy, but no Academy stores in SE Texas have new group 31's in stock.