# Anyone have experience with Deka/Duracell AGM batteries?



## killarney_sailor (May 4, 2006)

We need new batteries and are not sure if we can wait until we reach the US. I want to buy 4 - 4D AGM batteries so price does matter. We can buy Deka or Duracell AGMs - the Island Water World manager says they come from the same factory. Is this true? Anyone have real world experience with these batteries. They are much cheaper than Lifeline.


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## aa3jy (Jul 23, 2006)

..as are the West Marine branded batteries and a few others as well..at the East Penn Manufacturing plant in Lyons, Pa. About an hours drive my from location as I will be replacing my batteries this spring..

http://www.eastpennmanufacturing.com/divisions/motive-power/


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## Maine Sail (Jan 6, 2003)

killarney_sailor said:


> We need new batteries and are not sure if we can wait until we reach the US. I want to buy 4 - 4D AGM batteries so price does matter. We can buy Deka or Duracell AGMs - the Island Water World manager says they come from the same factory. Is this true? Anyone have real world experience with these batteries. They are much cheaper than Lifeline.


They are the identical battery but please spend your money on AGM batteries wisely. The Deka product is not a true deep cycle AGM like Lifeline or others it is a dual purpose battery with a factory lab life cycle rating of 300-350 cycles..

If you want a good Deka/East Penn product their GEL batteries are terrific, their AGM's not so much... There is a reason they are a cheaper AGM....

If you stay with AGM there are four premium AGM batteries Lifeline, Odyssey, Northstar and the new Firefly should be included but they only offer a group 31. Trojan has a new AGM coming out but I've not yet seen any hit the street and we have no real world experience with it..


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## killarney_sailor (May 4, 2006)

Because of the configuration of our batteries, we need to use sealed batteries. I have always thought that AGMs were superior to gels. Is this true?


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## Maine Sail (Jan 6, 2003)

killarney_sailor said:


> Because of the configuration of our batteries, we need to use sealed batteries. *I have always thought that AGMs were superior to gels. Is this true?*


No not really...

GEL batteries are the kings of cycling and they can be some of the longest lasting deep cycle batteries made, in typical marine format. It is not just me who understands this Sandia National Labs has shown this true in government funded independent studies.

GEL's do however require a lower absorption charging voltage, 14.1V, and a higher than normal float voltage of 13.8V. All charging with GEL batteries should be temp compensated. This is not something the typical boater can do easily without system upgrades.

If you do these things GEL's will last a long time. Deka/East Penn rates their GEL batteries at 1000 cycles and their AGM's (depending upon your inside source) at just 300-350 cycles. This is using the same test criteria for both batteries done by the same manufacturer. For Deka GEL batteries this means up to 3.3 times the lab rated cycle life over their own AGM.... If your batteries could last 3.3X longer......

The reason GEL's went out of fashion, so to speak, is that Deka and others tried to tell folks they could be charged at regular flooded lead acid voltages. This quickly destroyed them and gave GEL a very undeserved bad rap. Deka then recanted and for 20+ years said 14.1V and 13.8V and this works beautifully and we have lots of GEL banks lasting well in excess of 10+ years. I have one bank in its 15 year and three or four beyond 10... I have no AGM banks beyond year 7-8 at this point in time and that is not because the owners have not tried.

Now that their market share on GEL has plummeted, and been eaten by AGM, which is giving them another bad rap on longevity, they have once again begun telling people it is okay to charge GEL at higher voltages.. "Stupid is as stupid does."....

My buddy Bruce sailed around the world TWICE on the same set of GEL batteries. I don't know of any other double circumnavigation with any other battery type out there. Perhaps there are, but that feat is damn impressive especially considering the abuse he put them through.

AGM batteries certainly have benefits, such as high charge acceptance, but long cycle life, beyond a typical deep cycle flooded battery, is not necessarily one of them. Premium AGM's can have decent cycle life but it requires dedicated patience & a good system to get there.

All sealed valve regulated lead acid (VRLA) batteries require a proper system approach to use and charging..


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## hellosailor (Apr 11, 2006)

Even Deka, in their product sheets, says very bluntly that GEL IS BETTER THAN AGM by a huge factor. Call 'em up, ask about the # of cycles at 80% discharge or even 50% discharge, there's no contest.

However.

AGM's can drop into conventional electrical systems, while gels will be quickly and permanently damaged when charged at conventional voltages. So unless all your charging sources (regulators, etc.) can be set to "gel" and matched to the factory recommendations, you can't install gels without trashing them very quickly.

Often that can be simply throwing a switch, or something equally simple.

Lifeline AGMs are also very different from just about every brand on the market. Among other things they can and should be equalized--which would literally cook off and destroy Deka and other conventional AGMs.

Pros and cons to each one.


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## mbianka (Sep 19, 2014)

Glad to see this discussion. I've got two group 27 Gels for my 12 volt house bank and four 8A4D AGM's in series for my 48 volt propulsion bank. All were installed eight years ago and all seem to be holding up well. Of course they all were either charged by proper 120 volt chargers and solar controllers set for each types battery chemistry. I have no alternator for charging. Will be interesting to see which set needs replacing first. Not that I'm in any hurry to find out.


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## aeventyr60 (Jun 29, 2011)

Which solar controllers are you using?


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## IStream (Dec 15, 2013)

hellosailor said:


> ...Lifeline AGMs are also very different from just about every brand on the market. Among other things they can and should be equalized--which would literally cook off and destroy Deka and other conventional AGMs...


Minor correction. Here's the direct quote from the Lifeline Technical Manual, latest rev:
"Conditioning should only be done when the battery is showing symptoms of capacity loss due to an extended time in a partial or low state of charge condition." It's true that they can be equalized (conditioned in Lifeline-speak) but it shouldn't be done routinely, i.e. on an automated schedule as many battery chargers will do with flooded batteries.


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## Maine Sail (Jan 6, 2003)

IStream said:


> Minor correction. Here's the direct quote from the Lifeline Technical Manual, latest rev:
> "Conditioning should only be done when the battery is showing symptoms of capacity loss due to an extended time in a partial or low state of charge condition." It's true that they can be equalized (conditioned in Lifeline-speak) but it shouldn't be done routinely, i.e. on an automated schedule as many battery chargers will do with flooded batteries.


No battery should ever be equalized on an automated routine schedule and it horrifies me that companies build chargers that do this. It is as dumb as a box of beetle dung. If you have a charger or controller that does _auto equalization_ TURN IT OFF.....

And here is what Lifeline actually says when you break it down by type of _use_..



Justin Godber - Lifeline Battery said:


> (excerpted from Morgan's Cloud web site)
> 
> Put broadly, there are four ways that will yield different lifetimes based on daily 50% deep cycles:
> 
> ...


Unless you tie up to a dock after each sail and charge, or have an adequate solar array, most cruising or mooring sailors fall into category 4 though some will actually take the time to EQ once per month so some in category 3 as well. Even so the best outcome, as suggested by Lifeline, is 6-9 years., if you recharge to 100% after each and every discharge....


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## mbianka (Sep 19, 2014)

aeventyr60 said:


> Which solar controllers are you using?


I use Morningstar Pro Star 15's One is 12 volt the other 48 volt. No problem with either in eight years.


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## aa3jy (Jul 23, 2006)

hellosailor said:


> Even Deka, in their product sheets, says very bluntly that GEL IS BETTER THAN AGM by a huge factor. Call 'em up, ask about the # of cycles at 80% discharge or even 50% discharge, there's no contest.


Agreed..


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## Maine Sail (Jan 6, 2003)

aa3jy said:


> Agreed..


This is East Penn's own information given to West Marine and published in the West marine catalog..

Ignore my highlights for flooded batteries and focus on the East Penn GEL and East Penn AGM cycle life claims.


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## Icarus05 (Jul 28, 2009)

I too have to replace 2 x AGM 8A4D batteries. A friend of a friend can get them wholesale but I haven't pulled the trigger yet and won't until I find out what brand they are now that I understand they may not be true deep cycle.

I'm wondering if the same size in GEL would be an option. I have a Heart Freedom 2500 Iinverter/charger with a Link 2000R monitor. Would this system be acceptable for GEL charging?

The boat is new to us and we are away form it over the winter so I have not been able to dig into everything yet but have been thinking about battery replacement options for a couple of months. I though about moving to flooded 6Vs but that has its own problems with reconfiguration of the batt box, cables, etc. I think it would be a great option but so would a drop in replacement (with respect to size).


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## hellosailor (Apr 11, 2006)

http://www.xantrex.com/documents/Discontinued-Products/DataSheet/DS20041202R01_Fleet Power 2500.pdf

The manufacturer says yes, wet or gel. However, since every battery has slightly different voltage specs and not all chargers have ambient temperature compensation, you might want to check the specific optimum and maximum charging voltages for YOUR battery choice, and then make sure the charger is programmed correctly for them. (Or, can be adjusted to them.)

I asked Deka about using a solar controller that was spec'd at one or two tenths above the max rating for a battery, and they said to ignore the spec. Huh? If you can ignore it, why publish it?

Horseshoes (close is good enough) seem to be the new target goal.


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