Battery longevity

[lazybone]

My four house bank (generic  6v Sam's Club) batteries are dated 5/08 and seem to be holding a charge.  We are scheduled to relaunch next week and begin a cruise.  The batteries performed well last year but I'm beginning to wonder if 8 yrs is pushing things.  I'm leaning towards replacement because I don't want problems on the water but I would like to get a feel for how many years other folks get before I toss them.

[Roc]

I have the same ones (Energizer 6v from Sam's Club).  Had them since 2009 and things look good so far.  Funny you should post this because I was thinking about the same thing. 

[Steve McGill]

I vote for replacing. it's been 8 or 9 seasons.

They may hold a charge, but the actual AHs available must be much lower than when first purchased.

The cruise will be much better with a new bank.

Again, just how I would vote, enjoy the Bay.

Steve

[mark_53]

My four house bank (generic  6v Sam's Club) batteries are dated 5/08 and seem to be holding a charge.  We are scheduled to relaunch next week and begin a cruise.  The batteries performed well last year but I'm beginning to wonder if 8 yrs is pushing things.  I'm leaning towards replacement because I don't want problems on the water but I would like to get a feel for how many years other folks get before I toss them.

Do you have a dedicated start battery or a means of starting if they go tits up? If not, replace.  If so, use until you don't get the use you expect.

[lazybone]

I have a separate engine start battery which is also 5/08.

If it were up to me I would do a "Kramer" and see how far I could go when the gas light comes on but my wife would say "I told you so" with her fist.

[Footloose]

My vote is to replace only the starting battery.  Relatively inexpensive and you will have peace of mind that you can get home or to a marina.  Just my $0.02

[lazybone]

My vote is to replace only the starting battery.  Relatively inexpensive and you will have peace of mind that you can get home or to a marina.  Just my $0.02

That makes a lot of sense.

I guess what I'm looking for are a couple of responses that relate real experience.  " My batteries are 10 yrs old and going strong" or " I'm on my 13 yr and everything is fine".

[Paulus]

I got 8 seasons with my golf cart batteries.  Noticed that the 7th and 8th season that my freezer and refrigerator would occasionally not be running in the morning. Would have to fire up the honda and charge them.  The 8th season had a few times when the engine would not start on the house bank.  I would switch to the starting battery.  I did have a good starting battery. At the end of the 8th season, took them in for testing.  They all had lost AH but one battery was worse than the others.  Choose to replace all of them.  Also, depends on the type of sailing you do.  We are out for 3 months.
Paul

[Ron Hill]

Ciao : The only way you really know the "health" of any large battery, is to put it on a draw down tester!
That puts a load on the battery and will let you know Red/Amber/Green.

A thought

[Stu Jackson]

Ron's right, of course.  None of us know how to you treat your bank(s), what your usage is, and your charging regimens.  Many folks have gotten more than 8 years out of their bank(s).

It could also be something like reefing:  if you think you should, then do it! 

Maine Sail has written about battery testing, and either you take them off the boat and bring them in, or you do a 20 hour load test with a controlled 5A load.  I'll see if I can find a link.

Short story: what other people have done with their bank(s) is completely immaterial to your situation.

[Stu Jackson]

Battery Testing from Maine Sail:

20 hour capacity test

http://forums.sailboatowners.com/index.php?threads/battery-replacement-agm.179118/#post-1295253

[lazybone]

I was hoping for the short answer to ,how long do your batteries last?

Boating is so complicated.

[mainesail]

I was hoping for the short answer to ,how long do your batteries last?

B

There is no single answer because humans & crappy equipment get in the mix... A while ago we did a Battery Use Survey on Sailboatowners.com here is a brief summary:

The survey had approx 1300 responses:


*98.2% of all responses were from sailboat owners and the remainder mostly trawlers.

*79.3% of all responders spend less than 25 overnights on-board that may require a 50% depth of discharge. 46% of those responses were 10 nights or less.

*74% of all responders are using a 1/2/BOTH/OFF battery switch.

*74% of all responders are using one large house bank.

*66% of all responders use the house bank for everything including starting

*33% of responders use a dedicated direct wired starting battery to start the engine

*29% of all responders are using Deka/East Penn / West Marine / NAPA etc. batteries and this is the most popular battery in the survey. 2nd most popular are Wal*Mart / generic auto parts store batteries at 19% and then Trojan at 13%.

*57% of all responders are fusing the house bank

*46% of all responders are fusing the starting battery as well

*64% of responders using 12V Group 24, 27, 31, 4D & 8D batteries reported 5 years or less service life.

*63% of responders using 6V or 12V golf cart batteries reported 6 years or more service life.

*73% of responders using standard AGM batteries reported 6 years or less service life.

*84% of responders using GEL batteries reported 7 years or more service life with 32% of those responses being over 10 years.

*75% of responders with dock sailed boats reported 6 years or less service life.

*66% of responders with mooring sailed boats reported 5 years or less service life with 3 years service representing nearly 36%..

*60% of responders who monitor voltage for SOC reported 5 years or less service life.

*88% of responders who use an amp hour counting battery monitor reported 5 years or more service life.

*89% of responders who monitor SOC by "when the light dim I charge" reported less than 4 years of service life.

*85% of responders who said they use an automotive battery charger reported 5 years or less service life with 37% of those responses being less than 3 years service life.

*43% of responders who admitted to never equalizing batteries get less than 4 years service life.

*66% of responders with stock alternators report less than 5 years service life.

*80% of responders with high performance alternators report 5 years or more service life with 59% being more than 6 years.

*86% of responders who deem it time to recharge at a low of 12.2V reported more than 5 years service life with 61% responding 6 or more years.

*94% of responders who deem it time to recharge at a low of 11.8V reported 3 years or less service life.

*83% of responders using "generic auto parts store or Wal*Mart type batteries" reported 5 years or less service life.

*61% of responders splitting house duties by alternating between two banks reported less than 5 years service life.

*73% of responders using one large house bank report more than 5 years of service life and nearly 50% of those responses were 6+ years..


The "I get less than satisfactory battery life" responders:

*86% of responders who said they get "less than satisfactory life" are seeing less than 3 years from their batteries. 65% of those 86% reside on a mooring or at anchor. Of that 65% on moorings/anchor 80% have only an alternator for charging.

*60% of the "I get less than satisfactory life" responders have no idea as to how many amp hours they use and 90% have never done an energy budget yet nearly 66% have refrigeration and 67% have an inverter.

*78% of the "I get less than satisfactory life" responders don't even consider charging until 11.8V or less.

*68% of the "I get less than satisfactory life" responders are using flooded lead acid batteries and 30% are using standard AGM.

*92% of the battery group types used in the "I get less than satisfactory life" responders are 12V Group 24, 27, 31, 4D or 8D....

*67% of the batteries in the above group are made up of generic re-branded batteries such as West Marine, Wal*Mart etc. and 18% were standard AGM.

*67% of the the "I get less than satisfactory life" responders said they never equalized.

*87% of the "I get less than satisfactory life" responders do not use temp compensated charging equipment. A full 29% of users who answered this way have tried to use a battery warranty but did not have success..


From this it is easy to see why batteries die and boaters get less than satisfactory life........;) If there is a general take away then this would be it..

Owners who actually care to get longer battery life do and can. Owners who don't won't...

Quite honestly I was surprised by the differences between a battery monitor and voltage only monitoring. We all know most battery monitors are so grossly calibrated that they are near useless in terms of any measure of SOC accuracy. The one thing they do very well is to get owners to look at them and in turn pay attention to the bank. This, I have said for years, is what is causing owners to get longer life even with a grotesquely programmed battery monitor. We simply don't have enough data on the Smart Gauge to make any decisions. Based on its accuracy however I can only see the results ten years from now showing a nice improvement in battery life.

It seems the results show that owners who at least try to treat their batteries well do better than those who treat them as an out of sight out of mind tool that is used then put away...

There were a bunch of other little gems in there too. Such as 82% of owners who use temp compensated charge equipment get 5 years or more service life with nearly 40% of them exceeding 7 years. In contrast 78% of those who answered no temp compensation are getting 5 years or less service with nearly 40% of those below 4 years. This to me says that temp compensation is not just an option but a tool that is the necessity the battery manufacturers say it is.......

It is also very clear that we as sailors are not killing our banks by using up all the deep-cycles. In contrast we are murdering our batteries due to poor use, crappy charging sources and poor charging practices well before the cycles have been used up.

Another point that was pretty clear is that owners using automotive type chargers have pretty dismal service life from their batteries.

When broken down by battery group type or chemistry type the results were also interesting but not surprising. 12V pseudo deep cycle flooded batteries such as Group 24, 27, 31 4D & 8D had considerably shorter reported service lives than did true deep-cyle batteries such as 6V or 12V golf cart batteries. Brand to brand there were no real stand outs, but group type to group type there were..

In terms of service life longevity GEL was the consistency winner, along with 2V industrial batteries, with deep cycle flooded batteries such as 6V or 12V golf cart batteries coming in next. Standard AGM's beat pseudo deep cycle 12V batteries, but they were very hit or miss depending upon what type of use they had. Many AGM owners reported 3 years or less and some reported higher than average and it all came down to how they were treated. All in all not much has changed....

    *Charge Them Correctly
    *Equalize When Needed
    *Check The Electrolyte
    *Use Temp Compensation
    *Choose True Deep Cycle Batteries (when they can fit)
    *Get Them To 100% SOC As Often As Is Possible
    *Don't Over Discharge
    *Don't Let Them Sit At Partial States Of Charge
    *If All You Have Is an Alternator - Add Solar
    *Use true smart charger snot just in "sticker only"