Battery Brand Preferences?

[lifeofreilly57]

I'm replacing my two 8D house batteries and am asking for owners experiences with the different brands of deep cycle 8D wet cell batteries. The prices vary dramatically and I also understand that price is not always an indicator of battery quality.
In the past I've had outstanding performance from lower priced batteries than the more pricey brands. All with the same charging system on my previous boat, the difference is that the previous boat had 4 group 27 batteries and this has two 8D batteries, I don't have a ton of experience with these larger batteries and don't know who's brand tends to deliver the best price/performance ratio.
We're looking to take off for 3-5 years this fall and I'd like to get a set that will last for that duration.
I've had battery sets last for up to 7 years in the past by meticulously maintaining/charging them and have a very good charging system on this boat but also understand that the battery bank will be coming under constant daily use, so I don't see getting 7 years out of a new set.
Just the same, what brands have you used? What was your experience with those brands?

[john61ct]

Automotive sized batts like 8D in 12V are 99.99% "dual use" starters, not actually designed for true deep cycling.

The best battery value by far is Duracell (actually Deka/East Penn) FLA deep cycle golf cart batteries, 2x6V, around $200 per 200+AH pair from BatteriesPlus or Sam's Club.

If you can convert your bank space to GC or GC2 sizing you will cut your bank $ / AH / year costs by **a lot** and get better reliability.

Rolls / Surrette & Dyno are the only exceptions to the above "8D rule" sold in the US, properly cared for will last **much** longer, but they are very expensive and harder to source.

[rbk]

Just went through the battery research for replacing our house bank and found that the GC2 6V golf cart batteries mentioned above from NAPA are actually Deka’s made be East Penn. From what I could find NAPA had used them for years then switched to another producer with poor results so 7-8 years ago they switched back with great results and happy customers again. A number of their batteries but not all are manufactured by east penn so not sure about the 8D’s. Reports of people getting 7+ years out of their banks problem free. I ended up reading a bunch of Golf cart forum reviews (didn’t know such a thing existed) but they seem to put batteries through hell especially in places like Arizona with massive heat cycling and battery drain.

[sailjumanji]

I got almost twelve years out of Deka Group 31 AGMs. As such, I replaced them with identical. I highly recommend Deka made by East Penn.

[delmarrey]

My last set of Interstate Marine batteries lasted 7 years.

[lifeofreilly57]

Thanks for the feedback.
I'll have to measure the space available, come up with the total amp hours of the two current 8D's, which served our needs and see what I can fit if I go to the 6V cart batteries, I've also read about similar systems and their pros and cons, so it's not far off what I've been considering.
The boat came with a good charging system from Ample Power and a 5K generator, so keeping the batteries properly maintained should be no problem, we are also currently deciding whether to go wind or solar so there will be multiple ways to meet our demands, currently leaning toward solar.

[john61ct]

Take the NAPA statement with a grain of salt, such contracts can change year to year.

Deka has always been a EPM brand, Duracell more recently, but afaik permanently.

EPM/Deka FLA fantastic, GEL also good, but AGM are meh, not great for deep cycling.

Interstate also meh, re-labeller only, supply contracts can change year to year. They supply Costco's "Energizer" GCs BTW

Anecdotes of lasting X years likely not based on benchmarked residual capacity, 5-7 years very easy to do with poor quality if you push past 60-70% SoH, lower DoD cycling, many variables.

The only FLA as good / better than Deka/EPM are Trojan, Crown, Superior, US Battery, Dyno, and Rolls/Surrette at the top.

All are more expensive and harder to source than the Duracell/EPM GCs.

[Bleemus]

Batteries Plus shows a few different models of Duracell GC2. What model are you targeting and why?

https://www.batteriesplus.com/search?q=Duracell+gc2

[john61ct]

Any of the Duracell FLA GCs will do, similar AH capacities, same internal chemistry and construction

black one is the GC2 - 215AH Deka Pro-Master GC10

230AH is the EGC2 called the GC15

235AH is the Deka GC25

Avoid the Deka AGMs

[lifeofreilly57]

Thanks for the info, it's extremely helpful.
Much to figure out.

[Bleemus]

Thanks John.

[keepondancin]

2-GC2's will fit in the same box as 1 4D. Your back will be a lot happier dealing it 2 60+# batteries rather than 1 120+# battery

[lifeofreilly57]

Originally Posted by keepondancin

2-GC2's will fit in the same box as 1 4D. Your back will be a lot happier dealing it 2 60+# batteries rather than 1 120+# battery

I can appreciate the back saving aspect, I don't look forward to pulling the 8D batteries in the boat now, I just had to get the transmission out of the boat by myself so I can bolt it to the newly rebuilt engine to run it in the garage before re-installing it. I'm no spring chicken and not quite the buff muscled youth I once was. This boat rebuilding stuff has got me getting back to the gym, just so I can do what I need to do without needing to go to the chiropractor.
Ibuprofin is my friend.
Cheers

[ranger58sb]

Originally Posted by keepondancin

2-GC2's will fit in the same box as 1 4D. Your back will be a lot happier dealing it 2 60+# batteries rather than 1 120+# battery

Maybe 3, 6 in two boxes.

-Chris

[lifeofreilly57]

The more the merrier.
More reserve power, but also a bit more wiring.
Thanks.