Batteries (Life Span)

[Randyonr3]

So I'm reading and hearing info of Batteries on your boat only lasting 5 years (give or take) ..

Now we installed our "Lifeline" 4ds about 10 years ago and they are still opperating at better than 90%.. we're hopping to get 20 plus years out of them.. and we use them, as we live aboard, ..
We have 8 on board at present, batteries have never seen below 12.6 volts..
(at better than 500 per copy, I couldnt live with 5 years)

[Dsanduril]

With pretty much all batteries it's not years, it's cycles. Lead-acid batteries are variously rated from somewhere around 500 cycles to somewhere around 2000. Depends on the manufacturer, the depth of discharge of each cycle, the state of charge at the end of charging, equalization. Newer batteries (various lithium, etc.) are generally rated for more cycles, or greater depth, or don't require top-end charging.

If your batteries have never been below 12.6 then they have never been discharged much. Lifeline would say that they have only been discharged 10-20% of capacity. At that level of discharge the manual says 2500 cycles. At 50% DoD it says 1000. Depending on how long your charge-discharge cycle is (is it daily?, do you discharge for three days, then charge?) you could get a very long life. For those that discharge more deeply five years is a good lifespan (a 1000 daily cycles at 50% is only a three-year nominal life).

http://www.lifelinebatteries.com/manual.pdf

[noelex 77]

Battery life is very variable depending on how you treat them and the initial quality.
5-8 years is often quoted for flooded lead acid batteries.

I did get 18 years out of some Sonnenshein batteries. They were used cruising for about 90 days a year.
I thought this was exceptionally good and would be amazed if you achieve 20 years full time use, but a bit of optimism is always a good sign in a cruising sailor.

One thing to consider is that your batteries are going to die of old age more than the number of cycles. A smaller battery bank is likely to be more cost effective.

[barnakiel]

We had a starter battery from Varta that came with the boat and effectively gave about 10 years of service.

Our house wet cell batteries never last beyond 3 years. But we do abuse them.

b.

[Maine Sail]

The problem with "how long do batteries last" discussions is that everyone's "end of life" measurements are different. I have one customer who determines his battery death when it can no longer power his VHF to call the launch. He "gets" six years out of a battery that was in actuality technically dead by year three.

As an example I have two 2007 batteries in my shop right now both installed in the spring of 2007.

Battery #1 a group 27 deep cycle wet cell has 100 CCA left in it and is toast. Owner had no volt meter, no battery monitor, charged only via alternator and once in the fall via shore charger. He got 3 years out of it and it's been effectively dead for the other three though still powering his average load of just 2A (depth & plotter)...

Battery #2 a group 31 deep cycle wet cell had a battery monitor, solar for mooring charging and was better cared for over all. It is rated at 675 CCA and still puts up over 800 CCA (both Midtronics and Argus analyzers). The battery is in near perfect working condition and will likely go another two to three years. It just ended its sixth season..

The OP's life out of his AGM's is what I would consider atypical. Average life for mooring sailed boats up this way is about 2-3 years on AGM's if there is no solar or wind to get them to "full". It can bump to 5-6 with solar or wind augmentation but that is at the long end of average. I have a bank of 4 Lifeline 6CT's that are four years old and a bank of Lifeline 4D's that are three years old that both need replacement in the spring. Both boats are mooring sailed one a J 42 and the other an Able 42. Both owners have battery monitors etc. but lack the ability to fully charge their batts. I just finished installing solar on the Able and the J 42 will get it in the spring with the new batteries.

On our own boat we are at the end of year six on cheap deep cycle wet cells. The batteries are performing flawlessly. Entire bank cost us $210.00....

Batteries don't die, they get murdered....

[colemj]

Are you cruising and cycling the batteries, or living aboard almost always on a charger?

If the batteries have never been below 12.6V, you either have a fantastic off-grid charging system and live where there is limitless solar, wind and/or fuel, or use almost no electricity, or are plugged into a shore power charger most of the time.

If you are running off a shore power charger, you could get by with a $35 Walmart battery for 10yrs.

We have not yet met any full-time, off-grid cruisers who get 10+ years usable life out of their batteries, regardless of the battery type and charging systems. They may exist, but not in the 1,000's of boats we have met so far.

Among the cruisers we have met, lifespans of AGM's have been by far the shortest among the battery types. Gels seem to be the longest lifespans, and flooded between the two. We have only met two boats with LiFePO4 and those were brand new. Ironically, AGM's seem to be the most popular type, gels the least popular, and flooded between the two. Go figure.

Mark

[cfarrar]

Keep in mind that you can equalize Lifeline AGMs. Check out the well written "Indepth AGM Battery Test" by John at Adventure Cruising (look under the "Electrical" tab).

[tartansail]

Originally Posted by Maine Sail

Batteries don't die, they get murdered....

Agree. And we murdered our house bank this year with a combination of inefficient refrigeration, no supplemental charging and a couple of extended periods off the boat with the batteries left too low. I plead guilty and am planning a rehab program including solar on the bimini and replacing the three Gr27's with the Sam's Club golf cart batteries you reviewed elsewhere. (I've already begun working on the refrigeration, but that's not for this thread.) In assessing the level of mortality in the three house batteries (all the same age and make), I found very different resting voltages when I isolated them and let them settle for a couple of days. One was at 12.2; one at 11.6 and one was about 10.5. They were all paralleled in a single bank and had about the same levels of electrolyte with no dry cells. It makes me think that I actually only fully killed one of the batteries, but I understand that I'll still need to replace them all. Does the variation in voltage suggest anything about the setup to avoid so that I'm not committing selective murder again?

[Stumble]

David,

It makes me think that your batteries are wired incorrectly. Hooking up batteries into a bank seems pretty simple, but this is one of the few cases where the most elegant looking installation is also wrong.

Take a look at SmartGauge Electronics - Interconnecting multiple batteries to form one larger bank for a few different ways to wire batteries for better balancing.

[Cheechako]

Originally Posted by Dsanduril

With pretty much all batteries it's not years, it's cycles. Lead-acid batteries are variously rated from somewhere around 500 cycles to somewhere around 2000. Depends on the manufacturer, the depth of discharge of each cycle, the state of charge at the end of charging, equalization. Newer batteries (various lithium, etc.) are generally rated for more cycles, or greater depth, or don't require top-end charging.

If your batteries have never been below 12.6 then they have never been discharged much. Lifeline would say that they have only been discharged 10-20% of capacity. At that level of discharge the manual says 2500 cycles. At 50% DoD it says 1000. Depending on how long your charge-discharge cycle is (is it daily?, do you discharge for three days, then charge?) you could get a very long life. For those that discharge more deeply five years is a good lifespan (a 1000 daily cycles at 50% is only a three-year nominal life).

http://www.lifelinebatteries.com/manual.pdf

or in some cases... lack of cycles.... (Sulphating)

[Cheechako]

Originally Posted by Randyonr3

So I'm reading and hearing info of Batteries on your boat only lasting 5 years (give or take) ..

Now we installed our "Lifeline" 4ds about 10 years ago and they are still opperating at better than 90%.. we're hopping to get 20 plus years out of them.. and we use them, as we live aboard, ..
We have 8 on board at present, batteries have never seen below 12.6 volts..
(at better than 500 per copy, I couldnt live with 5 years)

if they've never ben below 12.6 , how do you know they are still good? Maybe they just hold a surface charge well....

[tartansail]

Originally Posted by Stumble

David,

It makes me think that your batteries are wired incorrectly. Hooking up batteries into a bank seems pretty simple, but this is one of the few cases where the most elegant looking installation is also wrong.

Take a look at SmartGauge Electronics - Interconnecting multiple batteries to form one larger bank for a few different ways to wire batteries for better balancing.

Many thanks for the link. Now bookmarked. I wouldn't be surprised if mine were wired the incorrect way when installed by the PO, but, unfortunately, I didn't label them prior to disconnecting and bringing home. If I proceed with four golf cart batteries, it looks like the wiring will be relatively easy since they will behave much like a pair of 12 volts.

[foggysail]

Maybe life is related to cycles as manufacturers state. Maybe full charge voltage has more to do with life along with equalization. Yes, I managed to get over 5 years from a no name pair of either 4d or 8d, not sure what they were other than big and heavy. I expect the short life in those batteries was the fault of good refrigeration and poor battery charging.

Now this brings my car batteries to the topic. I don't remember ever getting more than about 5 years from wet cell auto (starting) batteries nor have I ever actually measured the full charge voltage on any of them. But my guess is the regulators charge curve resembles those curves found in older marine battery chargers such as the resonant chargers where the cut off was around 13.8vdc, way to low for good battery life.

Now my driving history is just that..........drive the car/van, not park it and see how long the battery can supply power to headlights and such. The point here is that they really never did cycle much away from full charge what ever full charge happen to be determined by the regulators. Think about it!

Foggy

[DeepFrz]

Most batteries installed in cars are pretty cheap and we (I) have a tendency to "value" shop when replacing. Replacing with a good grade of battery will usually insure a long life, unless you drain them completely a few times, then they don't have a long life. All it takes is leaving the map light on overnight. I understand that the built in regulators have improved in recent years as well. I have been able to get 7 yrs. out of a good battery even here in frigid country.

[foggysail]

DeepFrz--

I am not sure one should consider all inexpensive batteries to have cheap construction. Yes it is a competitive world out there.

An example is the Penn golf cart sold by Same's Club for under $80. Similar batteries, I do believe they are the same Penns with different lables are sold by West Marine for twice the cost. Without any facts, just my gut intuition I believe that battery performance is closely related to keeping the thing well charged.... over 14vdc and equalized periodically.

This last summer I installed 4 of the above mentioned Penns rated at 230AH from Sams. THESE I WATCH CAREFULLY, not like I abused the ones these replaced. I have a Xantrex 50 amp 3 stage charger.....AND NO, I AM NOT A XANTREX FAN that does a moderately good job getting the charge voltage higher than my old charger did, 13.8vdc. But my solar regulator, ProStar 30 does a good job getting th batteries up to 14.4-14.5, forgot exactly the upper limit. Next season I expect my solar system to carry the bulk charging needs

Just my thoughts--

Foggy