Batteries

what type of batteries are you using ?? I have a 36 ft albin which currently has 6 house batteries flood type. and one starter flood. They were put in in 2013. I think its time for replacement and asking what type/manufacture most folks are using . mine are group 24 ... thank you

Two flooded 8D batteries for house loads and starting the single engine. They also run the windlass and bow thruster. The generator has it's independent starting battery, I believe group 27, also flooded. This system has worked well for us.
We have a Magnum 2KW inverter/charger.

What leads you to believe it's time to replace them?

Battery life is measured in cycles, not length of time in service. The cycle rating of batteries is dependent on the construction of the battery and typical depth of discharge of each cycle. Frequent deep discharges shortens battery life as does chronic under or over charging. So the battery that does a really great job for me might not fare so well under the conditions you have. If your batteries have lived much of their life dockside, they may have many cycles left. It's not enough to look at the battery, as it's only one piece of the puzzle. Better to take a system approach and consider the battery as a part of the system, and insure that the battery is a good fit within that system.

If you spend a great deal of time at anchor and your bank is routinely not fully floated, anticipate shorter life. How is your bank recharged?What is the AH capacity of the bank? What's your typical DOD% (depth of discharge)per cycle? Does recharging always charge fully to float? Any solar? Is your engine capable of fully recharging the bank? Smart charger? Smart alternator regulator? Battery temperature controlled charging? All impact life expectancy, and the better your system is at returning the bank to 100% recharge, the longer the bank will last.

If there is some question about the present condition of the bank, if it's flooded a test of the SG (specific gravity) of the electrolyte could give some indication of the condition. Load testing would augment that, and provide additional input in determining battery life status.

I`m with Maerin. Because your batts are flooded type you can easily test them for specific gravity with a hydrometer, which costs very little and should come with instructions, or find them online. Don`y just change them without testing unless you really want to.
2013 batts could be getting towards problems, but do a test. Load testers are not expensive either, check ebay.
FWIW, I have 8Ds. Don`t forget one bad batt in a bank sucks the power out of the good one(s). And if you replace one baddie the new one is better than the other oldies, so you may need to make a judgement there.

How your batteries are charged can also have an affect. Charging house and starting battery through a combiner will shorten the life of your starting battery. Mixing different types of batteries in one bank will affect battery life. Even unbalanced wiring of parallel banks can shorten a batteries life. As said before, a whole system approach is best.

KEVMAR said:

what type of batteries are you using ?? I have a 36 ft albin which currently has 6 house batteries flood type. and one starter flood. They were put in in 2013. I think its time for replacement and asking what type/manufacture most folks are using . mine are group 24 ... thank you

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Is it easy for you to access and service your flooded batteries?

Are all seven of your batteries 12V G24s?

What is minimum CCA/MCA required by your engine? And what is CCA/MCA rating for your current starter battery?

How many Ah total in the house bank?

Do you want more house capacity?

How much capacity do you need?

What is your charging capability?

How much will budget impact your buying decisions?

It may be easy enough to upgrade your overall capacity, but as others have said, a systems approach would be best. That doesn't necessarily you mean you have to do everything in one fell swoop; you could replace one bank when necessary, later maybe upgrade the charger if needed, eventually upgrade another bank, etc.

My first guess is that G24s aren't the best choice for a house bank, unless maybe that's all that will fit in your available space. That might lead to questions about what's better, but that'll also depend on space, form factor, etc. Could be several 12V G31s might be better, or maybe a 2-3 pairs of 6V golf cart batteries would be nifty. Need more info.

FWIW, 8Ds and 4Ds are heavy; they have their place, but they also come with that disadvantage.

-Chris

KEVMAR said:

what type of batteries are you using ?? I have a 36 ft albin which currently has 6 house batteries flood type. and one starter flood. They were put in in 2013. I think its time for replacement and asking what type/manufacture most folks are using . mine are group 24 ... thank you

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Personally, I am using group 31 AGM batteries. Four for the house and one for starting. I chose AGMs because it is very difficult to maintain flooded cell batteries in my boat because of the placement.

It doesn't really matter what others are using, use what's best in your situation. You can test your batteries as some have suggested but if yours were installed in 2013, they are nearing the end of their expected life. You can keep what you have until they fail or replace them now. If you're just boating around home, failure shouldn't be a big deal. If you are heading out on a long cruise away from home where failure could be a problem, you might want to consider replacing them before you leave.

With the service life you have experienced, I wouldn't change things except to go to group 31s if you have the room.

The only reliable test for State of Health is the standard 20 hour load test.

Read this CMS HowTo, or jump to "accurate 20 hour capacity test"
http://www.pbase.com/mainecruising/programming_a_battery_monitor

Any thoughts on a brand of maintenance free batteries from North State Batteries ?

Top AGM makers for the US market are Odyssey, Lifeline and Northstar.

IMO rest not worth considering for true deep cycling.

And FLA much better value, only use AGM if the install space requires it, or high CAR required to minimize genset runtime.

KEVMAR said:

Any thoughts on a brand of maintenance free batteries from North State Batteries ?

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Do you mean "maintenance free" as in the automotive sense? Or do you mean AGM or gel "valve-regulated lead acid" (VRLA) batteries?

Haven't ever heard of North State Batteries....

-Chris

BruceK said:

I`m with Maerin. Because your batts are flooded type you can easily test them for specific gravity with a hydrometer, which costs very little and should come with instructions, or find them online. Don`y just change them without testing unless you really want to.
2013 batts could be getting towards problems, but do a test. Load testers are not expensive either, check ebay.
FWIW, I have 8Ds. Don`t forget one bad batt in a bank sucks the power out of the good one(s). And if you replace one baddie the new one is better than the other oldies, so you may need to make a judgement there.

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+1.

Cheers.

H.

ranger42c said:

Haven't ever heard of North State Batteries....

-Chris

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I think it is a distributor and not a battery brand.

All excellent advice on here. And I personally don't think 4 year old batteries should be considered at the end of their life. One of the best things you can invest in is a good battery charger. If you can find a 4 stage charger, that would be best. I know you will find a lot of 3 stage chargers. In a 4 stage charger, the 4th stage is "idle"...IOW, no charge is being put on the battery. The charger intermittently "tests" the battery and will put a float on it if needed. But having a float charge on your batteries continuously is not as good as having them at idle when they are fully charged.

And Listen to what Maerin said. That is excellent advice and an excellent post!!
My group 31 Odyssey AGMs are 2013 install and they are nowhere near the end of their life. My system theory is very similar to Steve's up above. I have 5 Group 31 AGMs for house AND start. And an isolated Optima GRP27 AGM for generator start. All maintained by a Magnum 2000w/100amp inverter/charger. I do have the original Charles 80 amp charger on standby if needed(it is usually when I make a mistake and that was only once). Another advantage with a charger like a Magnum is you can customize each charge phase to exactly what the manufacturer recommends...and not some "canned" charging profile that is simply "adequate".

john61ct said:

Top AGM makers for the US market are Odyssey, Lifeline and Northstar.

IMO rest not worth considering for true deep cycling.

And FLA much better value, only use AGM if the install space requires it, or high CAR required to minimize genset runtime.

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Right on John

john61ct said:

And FLA much better value, only use AGM if the install space requires it, or high CAR required to minimize genset runtime.

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Or maybe if off-gassing is a concern.

Might be useful for some folks to keep Odyssey PC-2150s (G31s) in mind for DC thruster use, partly because they offer huge cranking amps compared to most other batteries in that BCI Group, and partly because off-gassing may well be a concern if the batteries are mounted in living spaces (as for example under a forward berth).

But I digress...

-Chris

Any kind of lead battery has some off-gassing, if in a sealed box even AGM should be vented.

Fact that it's lighter than air does help in a boat.

And yes, those Odysseys are a very rare exception that proves the "avoid dual purpose" rule.

But the first issue the OP needs to clear up is, does the bank actually need replacing?

And that likely will need, unless he **knows** they're dead, a proper 20hr load test.

I have had good luck for decades over several boats with Lifeline AGM's.

Maybe useful reading for kevmar, RC (aka Maine Sail in other fora) ref selecting house batteries:

https://marinehowto.com/what-is-a-deep-cycle-battery/

-Chris

It is entirely possible, and quite likely, that 4 year old flooded G-24 batteries are at end of life, especially if they have actually been deep cycled.

In the flooded form factors of G-24, 27, 29/30/31 and most 4D and 8D batteries are really more of a dual purpose battery yielding less real world cycle life than a battery specifically designed for deep-cycling purposes, even if the label says "deep cycle"...

What is a Deep Cycle Battery?

Also please don't be lulled into the understanding that a specific gravity test can tell you much about the state of health of a flooded battery. All an SG reading can tell you is the batteries state of charge or a cells SOC. You can also derive battery SOC from a resting open circuit voltage reading. SG is best used to discern cell imbalances and to help determine equalization schedules..

Even a battery suffering a 60% loss in Ah capacity, eg: 100Ah battery delivering just 40Ah's, can still put up a good SG reading. It's entirely possible, I see and measure it regularly, for that 100Ah rated battery to deliver a perfect SG reading when it can only deliver 40% of its original Ah capacity.

the batteries that are now in the boat are 6 volt golf cart battery GC2 and there are only 4 . the starting battery is 12 volt and all are flooded .. I miss quoted in my original post.

with that said can I replace the 6 volt batteries with 12 volt batteries. what would be the benefit of going to 12 volt, I presently have 4 6volt GC2 batteries Duracell .. should I replace 12 volt or stay with the same. they have been in use since 2013.

If you're happy stick with the same, can't beat the cost, take abuse, less stress trying to coddle them

What makes you think need replacing now?

There is no benefit going to 12V, more likely you get fooled by false labeling

KEVMAR said:

I think its time for replacement and asking what type/manufacture most folks are using . mine are group 24 ... thank you

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You say G-24 here...

KEVMAR said:

I presently have 4 6volt GC2 batteries Duracell .. .

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You say GC2 6V here??

Four years would be sub-optimal life for a GC2 bank yet decent life for a G-24 bank..

If you actually have GC2's in there now, and convert to G-24, you'll very likely cut your battery life in half.

A GC2 bank should quite easily go well beyond 5 years with averages closer to 7-9 years with good care & use practices. At 4 years either they are not dead yet or they've had sub-optimal care.

Good news is a GC2 bank is quite in-expensive so just replace it and continue on. If you're satisfied with 4 years of cycle life don't change anything, if you're not, then address the use and charging practices and you may even see double or beyond in the life of the bank..

KEVMAR said:

the batteries that are now in the boat are 6 volt golf cart battery GC2 and there are only 4 . the starting battery is 12 volt and all are flooded .. I miss quoted in my original post.

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KEVMAR said:

with that said can I replace the 6 volt batteries with 12 volt batteries. what would be the benefit of going to 12 volt, I presently have 4 6volt GC2 batteries Duracell .. should I replace 12 volt or stay with the same. they have been in use since 2013.

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Ah. That makes a big difference. Sounds like a decent house set-up, and if the capacity has been sufficient, maybe no need at all for design change.

(And replacing those with most 12V batteries would likely be a step backwards. See CMS links about deep cycle batteries.)

Next maybe would be to address why you think your current ones need replacement. Are you just reckoning that 4 years is long enough so that they're at end of life? Or are you actually seeing that you sometimes can't run some stuff on your current batteries?

What is your resting open circuit voltage reading? (i.e., after charging for say 24 hours, then unloading and resting for say 6-24 hours...)

If the batteries are fine but your capacity has still been insufficient for routine DC needs, and if you have space, maybe eventually adding another pair of GC2s could be nice. Common guidance is to replace all batteries in a bank at the same time, though (meaning it might not be great to just add a pair of GC2s to your existing 4-year-old GC2s).

-Chris

In our previous boat I had (2 x group 31) Cycle for the house and (1 x Group 24) Starting. all AGM Lifeline batteries. That setup was still working well after 9 years.

My current setup is (1 x 8D) House & (1 x 8D) Starting. These are both Lifeline AGM Deep Cycle.

IMHO you pay for the cycles (potential). Cycles will vary based on use and care. My personal opinion is you cannot get the same number of duty cycles from a lessor brand despite the same level of use and maintenance.

It's also my opinion that a house bank should be well oversized for it's use. I feel that you get much better battery life by drawing down very little and recharging to full. Rather than drawing down deeply. recharging to full and periodic battery conditioning is key.

"Rather than drawing down deeply. recharging to full and periodic battery conditioning is key.'

Very true , but unless a cruiser has good solar , or a 24/7 noisemaker chances are the usual time the batts get to 100% full is dockside.

AS that can be months between , oversized batts , to allow for the loss in capacity over time is always a great idea.

FF said:

"Rather than drawing down deeply. recharging to full and periodic battery conditioning is key.'

Very true , but unless a cruiser has good solar , or a 24/7 noisemaker chances are the usual time the batts get to 100% full is dockside.

AS that can be months between , oversized batts , to allow for the loss in capacity over time is always a great idea.

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Yes to above AND without solar, a very good battery charger is necessary for 100% charging! I am not current with present battery charger technology so I cannot comment as to any programmable ones being available if any. This I do know from personal experience, my Xantrex 5012 (or is it 1250?) does a horrible job of bringing my battery cells up to where they belong. Xantrex enters float way too early. My solar along with my Victron 150-70 does impressive charging and of course the Victron is programmable

foggysail said:

Yes to above AND without solar, a very good battery charger is necessary for 100% charging! I am not current with present battery charger technology so I cannot comment as to any programmable ones being available if any

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Sterling ProCharge Ultra and ProMariner Pronautic P are great user-adjustable lines.

Shrew said:

In our previous boat I had (2 x group 31) Cycle for the house and (1 x Group 24) Starting. all AGM Lifeline batteries. That setup was still working well after 9 years.

My current setup is (1 x 8D) House & (1 x 8D) Starting. These are both Lifeline AGM Deep Cycle.

IMHO you pay for the cycles (potential). Cycles will vary based on use and care. My personal opinion is you cannot get the same number of duty cycles from a lessor brand despite the same level of use and maintenance.

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The fact that you've used Lifeline for your AGMs is why, an "exception that proves the rule".

At the low priced end of the market, pairs of 6V FLA GCs are a great value, like $180 for 200+AH, but not those automotive form factors in 12V.