# Salvaging Deep Cycles



## adamtheha (Mar 14, 2007)

I have a feeling that my battery bank is destroyed, which is going to be a hard financial pill to swallow. I have 8 Surrette L416's wired in 24 V, and I have been charging with a generator daily. In the last two days, the charging voltage has been shooting up to maximum right away, but then when the generator is off, the batteries go flat right away...
I have been equalizing pretty regularly, and they are only 2 years old! 
How do I find and fix/remove a bad cell? I know that if I leave it, they will deteriorate further, but I need them to last another 6-8 months at least!
Has anyone actually had success temporarily rejuvinating deep cycles? How is it done? These are $400 batteries, so I would pay a bit of money to make something work.


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## Harry Chickpea (Dec 19, 2008)

See my post in the battery additive thread.

Having fooled around with lead acid cells, I am convinced that everyone needs to start out with training batteries that are cheap. I've ruined a number of them, even after knowing what I should do.

Were you recharging and measuring the S.G. after the batteries had rested? How low did the S.G. get when the cells were about to be charged? Did you do multi-stage recharging and did you use any desulfating circuit?

I won't say anything definite, but unless you have ready good answers for those questions, you may have a source of fishing weights.


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## Valleyguy (Jan 5, 2011)

adamtheha said:


> I have 8 Surrette L416's wired in 24 V, and I have been charging with a generator daily. In the last two days, the charging voltage has been shooting up to maximum right away, but then when the generator is off, the batteries go flat right away...
> I have been equalizing pretty regularly, and they are only 2 years old!
> How do I find and fix/remove a bad cell?


Not good but not the worst either. I have used the L-16 type battery in "severe service" and didn't get a long service life out of it. I know there are canned responses to battery life for the various types such as golf cart's last... L-16's last... which is just a rule of thumb, especially when you consider all the variables that can go into a daily use, off the grid type system. 

Actually 2 years for a heavily used or marginally maintained L-16 battery, well they may be at the end of their life. Seen it happen with GC's, L-16 and various AGM's. However, the key is this happened rather suddenly.

Have you tried the easy fixes like loose connections or hidden corrosion.

Checking the Specific Gravity may give you a clue also. You didn't mention that so I am just assuming you may not have a tester. That is right where I would go after checking the easy stuff.

Surrette/Rolls are good batteries. Which series do you have because they do have a warranty that is 2or 3 years replacement with prorated cost after that? Seems you wouldn't out too much if you have a bad cell somewhere.

You might already know this but the symptom you mention is common with heavy plate sulphation since the charge isn't effective.

Rick
*Homepage*: www.power-talk.net
*Forum*: forum.power-talk.net/


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## Jim-mi (May 15, 2002)

After your generator recharge- with a good digital multi meter- measure and record each bat. Put a load on the bat bank and measure again........
Load the bank some more and measure again.........
Record all readings.......


good luck-


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## PD-Riverman (May 24, 2007)

I guess you are talking about L-16's. If you don't want to spend any money then If it was my batteries, after they start getting weak I would seperate each battery then put each battery under a load and take the strongest 4 batteries and wire them in series for 24 volts then take the other 4 wired in series---then parrallel the 2 banks, maybe you can get a few months of use doing this. Good Luck!!




adamtheha said:


> I have a feeling that my battery bank is destroyed, which is going to be a hard financial pill to swallow. I have 8 Surrette L416's wired in 24 V, and I have been charging with a generator daily. In the last two days, the charging voltage has been shooting up to maximum right away, but then when the generator is off, the batteries go flat right away...
> I have been equalizing pretty regularly, and they are only 2 years old!
> How do I find and fix/remove a bad cell? I know that if I leave it, they will deteriorate further, but I need them to last another 6-8 months at least!
> Has anyone actually had success temporarily rejuvinating deep cycles? How is it done? These are $400 batteries, so I would pay a bit of money to make something work.


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## adamtheha (Mar 14, 2007)

I do have a SG tester, and the SG has never been where it should be...I equalized, and followed all of the recommendations (after 6 months of mild abuse) but they were never quite in the "green" section. They were all the same though, so I figured it was probably not a big deal.
I could probably take the 4 best batteries, and wired them into a smaller bank, since it will probably give me about as much capacity as I have now...
Why can't we get a battery technology that is more reliable and easier to use??? I would pay double for something like nickel hydride, or what the Chinese invented for their plug-in hybrids. I hate lead acid!


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## Harry Chickpea (Dec 19, 2008)

adamtheha said:


> I do have a SG tester, and the SG has never been where it should be...I equalized, and followed all of the recommendations (after 6 months of mild abuse) but they were never quite in the "green" section. They were all the same though, so I figured it was probably not a big deal.
> I could probably take the 4 best batteries, and wired them into a smaller bank, since it will probably give me about as much capacity as I have now...
> Why can't we get a battery technology that is more reliable and easier to use??? I would pay double for something like nickel hydride, or what the Chinese invented for their plug-in hybrids. I hate lead acid!


If they didn't get back to the proper SG, that is likely the root cause of your problems.

You can be sure that people have been trying to make better batteries for as long as they have been around. What is deceptive is that since that they can be recharged, everyone thinks they can be recharged for an indefinitely long period of time. They have finite lifespans, which has a way of ruining a lot of pipe dreams.

There are other types of batteries out there, NiCads, Lions, etc.. The price is generally much higher though.


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## adamtheha (Mar 14, 2007)

I think I may have done something useful, the Surrette manual says to equalize the snot out of the bank, at the highest voltage that you can get. I've managed to get the specific gravity on the bank into the green zone, and I'm going to keep going. There is a noticable difference, the batteries take longer to reach charging voltage, and they have most of their capacity back.
For anyone who may have heavily sulfated flooded batteries, here's what you can try when all else fails:
1. Set equalization on the highest setting, and run for 8-10 hours. Do not let the electrolite go over 50 degrees Celcius. If it gets close, stop and let them cool down. 
2. Measure the specific gravity several times. Charge until it reaches the proper place, then charge a few hours more.

In short, equalize at the highest voltage you can for a long, long time. This comes straight from Surrette.


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## Harry Chickpea (Dec 19, 2008)

"the Surrette manual says to equalize the snot out of the bank"

Gotta love those technical terms...    If you are able to get them in the green zone, you have at least some life left in them. Good for you!!!


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## Jim-mi (May 15, 2002)

Where in lies the problem with many folk....

NOT ENOUGH CHARGE


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## Harry Chickpea (Dec 19, 2008)

A full charge can take a few days. I've pondered whether having two battery banks might be better in some situations. The finishing charge is not high current, just tedious. A second battery bank with a step-up system could easily supply the required voltage and current. Once the first one was fully charge, swap battery banks with a switch.


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## adamtheha (Mar 14, 2007)

Sorry, what? A full charge takes that long? I have often thought about having two battery banks, but it seems complicated.


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## trkarl (Dec 15, 2009)

Jim-mi said:


> Where in lies the problem with many folk....
> 
> NOT ENOUGH CHARGE



Exactly. And the only way to tell if your FLA batteries are getting charged properly is with a temperature compensating hydrometer.

What I did with my bank:
When first put into operation I commissioned it by equalizing until the sg stopped rising. 
Label each cell and record the sg of each cell. This gives you a baseline to compare to.
Every day or so check the sg after they have charged and you will be able to see if they are full or not. If it trends down you know you will need to adjust the charging voltage and/or absorption time.

The absorption time is the most important time of the charge. If it is not regularly done until they are full then the sulfate will begin to build up slowly but you won't notice it until it is usually too late.

After a while you will get the right "feel" and pretty much know from day to day whether they are getting charged or not.

Every few days I check a few cells in my bank to see where the sg is this way I know for sure what is happening.

Then follow a schedule for equalizing the bank. After each eq record the sg of each cell and date it. This way you can catch problems before they become real costly to remedy. This is real easy to do in a spread sheet format.

JMHO/YMMV


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