Batteries

I am looking into replacing my current set of batteries which consist of 5 wet cell group 27 batteries....4 house/start and one generator battery.

I am looking into AGM. The cheapest I can find retail are the West Marine brand Sea Volt at $280. These are Dekka made batteries and I have found them as low as $180 on line. Which isn't bad.

Now I have found that Sears makes an AGM Die Hard in the $150-180 range. They do call them "deep cycle" with a CCA rating around 800. But they do not show an amp/hour rating since they are not targeting a marine application. Just curious if anyone has tried these batteries? I am not saying I am going that route but I would be willing to bet that Sears would likely have the best warranty support....and these Diehards have a 3 year non-pro rated full replacement warranty.

I am open to suggestions. I am looking for value. And I would be willing to listen to arguments if a battery such as Lifeline is worth the extra money???

I have always had relatively simple 12 volt systems on my boats and they have always served me well. I do not spend tons of time at anchor on battery power only.

Can't answer your question John but thanks for finding out Sears has my new batteries

I've had good luck with Interstate AGMs.

Group 31 100 AH.

Bought a Dekka 8D AGM in 2011. It died this spring. One cell went bad. My dealer offered to prorate it. They offered a very small percentage. I said no thanks as I could buy 2 or 3 Lead Acid for the same money as an AGM. Have 2 8Ds in the boat and am back to replacing the house battery every other year and the engine battery every third year. Regarding AGM, I remain unimpressed with the product relative to the cost.

Ted

Ted

Baker said:

I am looking into replacing my current set of batteries which consist of 5 wet cell group 27 batteries....4 house/start and one generator battery. . . . . . .

I have always had relatively simple 12 volt systems on my boats and they have always served me well. I do not spend tons of time at anchor on battery power only.

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If your battery system is working for you, is there a reason you want to change your system? Unless you need more battery capacity, it sounds like your "simple 12 volt system" has served you well? How many years do your current batteries last you? That's usually a good measure of your battery systems health. Anything over 7 or 8 years and you're doing good.

I know someone else already mentioned them, but Interstate batteries are an excellent choice. Well made, heavy duty and many years of service. With the advent of smart chargers, I cycle out my battery banks at 10 years. I actually did 11 years on the last bank. The battery bank ages are staggered, so I have a bank of less than one year old batteries and a bank thats 5 years old. They're all wet cells.

What is the reason for using AGMs? Before you spend the extra money you should determine what you are getting that is not available from lead acid batteries at 1/3rd the cost.

Marty

I replaced my old AGM's (5 yr old Optimas) with Deka group 34AGM's from Sams Club for $110 each. They are not labeled Deka but Duracell. I must used AGM's as my batteries are inside a cabinet in the cabin so wet cells that gas are out.
I did have one fail in about 6 months and it was replaced with no problems.Also, Deka's are still made in the US...at least last year they were!
One consideration with AGM's is to make sure that your charger can charge them correctly. My old Newmar charger does not have a AGM setting but the charging rates and float rates are very close to AGM rates and I get good life from the batteries

I am not a fan of AGMs given the cost/performance equation.

But given that you are going to use AGMs, I don't think that there is a nickels worth of difference between a "marine" AGM and a generic one.

But there is a big difference in flooded cells. There are almost no Group 27 true deep cycle batteries with thicker plates, more depth under the plate to accumulate sulfate without shorting and at least in the case of golf cart batteries, more headroom over the plate for electrolyte.

Get the picture. Replace your 4 Group 27 house bank with golf cart batteries wired series/parallel. Use a Group 27 battery for the propulsion engine and genset starting or a separate Group 24 for the genset if you want the redundancy, although 4 GC batteries will start most engines easily, which gives you the redundancy.

Baker said:

Now I have found that Sears makes an AGM Die Hard in the $150-180 range. They do call them "deep cycle" with a CCA rating around 800. But they do not show an amp/hour rating since they are not targeting a marine application. Just curious if anyone has tried these batteries? I am not saying I am going that route but I would be willing to bet that Sears would likely have the best warranty support....and these Diehards have a 3 year non-pro rated full replacement warranty.

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Last time I looked, Sear Platinum Plus AGMs were made by Odyssey. Two sizes, one Group 31, one smaller (might be the size you're considering).

Odyssey calls 'em dual purpose batteries, and the larger of the two (PC2150 is Odyssey's number) offers major CCAs. The smaller Sears one is maybe Group 24, 27 or 34 equivalent, not sure... Anyway, you can look up specs on the Odyssey site, if those the Sears AGM batteries you're thinking of.

On sale prices at Sears are said to be very good, and of course if you can pick up locally, you (sorta) save separate transportation costs.

-Chris

djmarchand said:

I am not a fan of AGMs given the cost/performance equation.

But given that you are going to use AGMs, I don't think that there is a nickels worth of difference between a "marine" AGM and a generic one.

But there is a big difference in flooded cells. There are almost no Group 27 true deep cycle batteries with thicker plates, more depth under the plate to accumulate sulfate without shorting and at least in the case of golf cart batteries, more headroom over the plate for electrolyte.

Get the picture. Replace your 4 Group 27 house bank with golf cart batteries wired series/parallel. Use a Group 27 battery for the propulsion engine and genset starting or a separate Group 24 for the genset if you want the redundancy, although 4 GC batteries will start most engines easily, which gives you the redundancy.

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That's my setup and I agree I think AGMs are overated for what you get for the cost.

Edelweiss said:

I know someone else already mentioned them, but Interstate batteries are an excellent choice. Well made, heavy duty and many years of service. With the advent of smart chargers, I cycle out my battery banks at 10 years. I actually did 11 years on the last bank. The battery bank ages are staggered, so I have a bank of less than one year old batteries and a bank thats 5 years old. They're all wet cells.

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I have Interstate, also, and can't remember when I bought them (Would have to look it up.) They (3-8Ds) have been great, no worries, smart charged, AGMs.

I guess they are still in here.

Our assistance towing fleet had miserable luck with the interstate dual purpose marine batteries...and the towing company was an Interstate Batt Dealer when getting them off the truck.

My personal truck had Interstate starting batts and they seemed to be pretty good.

Maybe it's a model thing or a year group thing...but I always try for Decca as they have had the best rep around here for a long time.

West Marine batts are Dekka I believe unless they have changed and West did their own research for good batts.

SeaHorse II said:

I guess they are still in here.

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That sentiment in a nutshell is exactly why I am switching to AGM. Battery maintenance cuts into my leisure time.

I've had no issues with my 24-volt, 200AH, AGM batteries.

I bought my dinghy used, three years ago. Came with an AGM of indeterminate age. That same year I bought a lawnmower with the same size wet cell battery. The Dinghy always starts, even after a 6 month winter off. The lawnmower never starts without at least 12 hours of charging, and this has been the case for two summers now.

Most people have wet cells in their cars...never do a thing for 3-5 years..no complaints.....

It's all how you care for and feed a battery much more so than what it is.. AGMs have their plusses...but at the cost...many will dispute that if you understand and properly take care of wet cells (and for me that's about 5 minutes a year) that AGMs give you your moneys worth.

koliver said:

I bought my dinghy used, three years ago. Came with an AGM of indeterminate age. That same year I bought a lawnmower with the same size wet cell battery. The Dinghy always starts, even after a 6 month winter off. The lawnmower never starts without at least 12 hours of charging, and this has been the case for two summers now.

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I get the flooded v AGM comparison. A practical aside, buy the lawnmower(ride on?) a small maintenance solar panel, put somewhere it gets light during winter.
Many boat owners need a compass to find the house in the lawn jungle. I`d rather steer the boat than the lawnmower.

The very few boats with a large DC bank and the ability and desire to charge quickly is the market for AGM.

Otherwise why bother?

CPseudonym said:

That sentiment in a nutshell is exactly why I am switching to AGM. Battery maintenance cuts into my leisure time.

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My thoughts exactly. My batteries are somewhat of a pain to get to. So it would be nice not to have to maintain them.

BTW, they are 4 years old and group 31s. I will definitely look into Sams club.

I had an Optima generator start battery on a previous boat. I owned the boat for 7 years. That battery came with the boat and was still in the boat when I sold it. It's ONLY charging source was the alternator on the generator. That battery left a very good impression on me for Optimas and AGMs in general.

PS.... Based on the logic of the people who like wet cell batteries, we'd all be driving gasoline powered boats!!....ie diesel engines provide only slightly better performance and efficiency and are easier to maintain, but they cost a whole heckuva lot more money!!!

Baker said:

PS.... Based on the logic of the people who like wet cell batteries, we'd all be driving gasoline powered boats!!....ie diesel engines provide only slightly better performance and efficiency and are easier to maintain, but they cost a whole heckuva lot more money!!!

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I guess following that logic and your devotion to exotic battery technology, we should be looking for you in a Prius trawler soon.

Ted

I am at a loss why people "maintain" batteries...sure I check them randomly every couple of trips or weeks as the case may be...but I haven't added water to any flooded cell batts in years on my boat and several work boats I run.

If you are boiling off water....maybe it's not the batteries fault.

You need to be checking the connections for looseness and corrosion far more often than water in my book.

So while I appreciate AGMs for what they are...I don't get where flooded are that much trouble...

If you can't easily get to your batteries...as important as they are to getting around...just to be able to visually check and a couple quick tugs regularly...they should be readily accessible in any boat.

Oh well...I'd rather spend the money on my genset to run my ac even though I have a white boat and a manson supreme....

psneeld said:

So while I appreciate AGMs for what they are...I don't get where flooded are that much trouble..

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I agree. Most of it is advertising hype, very good hype too. Taking a step back, the logic of buying a 2 or 3X the cost battery to do essentially the same job with about the same longevity is a great marketing success.

I have two AGMs under the forward cabin sole for the thruster, a good choice for the relatively unventilated interior location.

As psneeld says, if your batteries are boiling off water maybe it is not the battery. Check for overfilling or a bad charger.

Baker said:

PS.... Based on the logic of the people who like wet cell batteries, we'd all be driving gasoline powered boats!!....ie diesel engines provide only slightly better performance and efficiency and are easier to maintain, but they cost a whole heckuva lot more money!!!

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Well, I strongly disagree with almost everything said.

Wet cell batteries have their place: long life, easy to measure state of charge, cheap. The one real drawback is that you do have to check electrolyte levels periodically. I typically have to add water once or twice each year.

So preferring wet cells doesn't make me a Luddite. It makes me a hands on boater.

Diesels are a lot more efficient than gasoline engines. A modern diesel produces 18-20 hp per gph and a fuel injected gasser produces 11-13 hp per gph.

Modern diesels require more maintenance: Ignore fuel filtration and water removal and you can trash a common rail diesel. A high output diesel requires servicing of its air cooler. Neither of these are issues on a gasser.

Diesels do cost about twice what a gasser costs but they do last a lot longer.

O C Diver said:

I guess following that logic and your devotion to exotic battery technology, we should be looking for you in a Prius trawler soon.

Ted

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Actually, quite the opposite. I was doing my yard the other day and my leaf blower and weed eater are made by Homelite(my chainsaw too). And I thought to myself, I have had these yard "implements" for 9 years and have done absolutely nothing to them but put gas/oil in them. They sit around all Winter totally inactive. And then start right up the next season. My leaf blower was $49 and my weed eater $39!!

Then I began fantasizing about a Homelite powered trawler.......

Back on subject, my batteries are not boiling off water. They are all Full...and still near death at 4 years old. I have only owned this boat a few months so have no clue how they were treated before me.

There are "unplanned" events that can occur that will harm certain types of batteries over another type. Like somebody turning off your shore power...or a breaker popping. Your wet cell batteries drain down(Fridge)....and then sit for a week in a depleted condition without a charge. Quite possibly the worst thing you could do to a wet cell battery. And that is what recently happened on my boat and is likely what finished them off. Maybe you are at anchor and not worried about managing power because the genset is on and you are pulling many amp hours and don't realize you forgot to turn the battery charger on and you have been running like this for 2 or 3 days....a deep discharge....again, wet cell batteries do not like that sort of treatment and if you have a few events like this on your battery bank, their life will be shortened. An AGM battery would be much more tolerant of this sort of treatment.

So I will agree....In a vacuum, maybe AGMs are not worth it. Add a little real life abuse and maybe a few imperfect events, and then they might be....along with the fact that they are maintenance free and do not spill and are much more resistance to physical movement(ie vibration) and are much more tolerant to differing charging profiles and cycles....

Thanks for the input!!! It is greatly appreciated!

djmarchand said:

So preferring wet cells doesn't make me a Luddite. It makes me a hands on boater.

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I'm sticking with my analogy. And just because I might prefer AGMs does not mean I am not a hands on boater....it just means I may prefer to put my hands somewhere else!

Baker said:

There are "unplanned" events that can occur that will harm certain types of batteries over another type. Like somebody turning off your shore power...or a breaker popping. Your wet cell batteries drain down(Fridge)....and then sit for a week in a depleted condition without a charge.

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That's exactly what happened to me last week. Forgot to switch on the charger (first time) while the boat sat in the marina with shore power hooked up. The house AGMs were down to 19% charge after one week's time due to the refrigerator. The four-hour Napa River run brought them up to 80%. Checked on them a couple days later and they were back to 100% after being charged from shore power.

Edelweiss said:

If your battery system is working for you, is there a reason you want to change your system? Unless you need more battery capacity, it sounds like your "simple 12 volt system" has served you well? How many years do your current batteries last you? That's usually a good measure of your battery systems health. Anything over 7 or 8 years and you're doing good.

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I am not looking into changing the system. Just the battery type. And if you are getting 7-10 years on your batteries, you are doing much better than most.

markpierce said:

That's exactly what happened to me last week. Forgot to switch on the charger (first time) while the boat sat in the marina with shore power hooked up. The house AGMs were down to 19% charge after one week's time due to the refrigerator. The four-hour Napa River run brought them up to 80%. Checked on them a couple days later and they were back to 100% after being charged from shore power.

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That is the kinds of things that happen when people use their boats!!!! We may not be perfect.....but we are having fun!!!!

O C Diver said:

I guess following that logic and your devotion to exotic battery technology, we should be looking for you in a Prius trawler soon.

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That would suit me to a "T". I'm on my 3rd Prius since 2007 (I lease my cars) and love them! BTW, I don't add water to my hybrid battery either, Must be an AGM? (of sorts)