Total life of batteries

[dloefffler]

Energy Bulletin has an article by Tom Murphy regarding battery life among other things solar.

His observation is that whether your are gentle with minimal discharge, or aggressive, the total amount of energy extracted doesn't vary much. This is the first time I have come across that idea, but it make sense. Might make an interesting read.

Dennis

[dnix71]

What matters is keeping the temp down, water when needed, and adding sodium sulfite. I have a bank of hybrid 12v marine deep cycle/start batteries and after adding sodium sulfite and using them for about a month they act like new again. The sulfite removes hard sulfates and prevents then from reforming.

It's cheap, too. eBay sells pounds of the stuff for cheap because it's also used to keep food and drugs from spoiling when exposed to air and humidity.

[gww]

Is ebson salt the same as sodium sulfite?  I saw on another post of someone using a table spoon of ebsom salt in each cell.
gww

[dnix71]

Epsom salts are magnesium sulfate. I didn't know what the magnesium would do so I bought pure sodium salt instead. Adding tetra sodium EDTA ruined two batteries right away. The batteries began churning and foaming after adding EDTA and then one cell shorted.

Adding sulfite only lowered the resting voltage a little, but when it bottoms out it holds at 12.6 for hours under moderate load.

[gww]

dnix71
I take it that sulfate and sulfite are two differrent animals.  What name exactlly would I buy and where other then ebay? 
Thank you.
gww

[dnix71]

http://www.ebay.com/itm/Pure-Sodium-Sulfite-Chemicals-for-less-5-Lb-/260682066997 This isn't the person who sold to me, but this is about the same price.

I bought from Dean Belshe 427 Carlyss Dr. Sulfur, Louisana 70665 337-583-2546 I don't know if that address and phone are still current, but you can try.

I still have some left from the purchase. If you can't get it any where else let me know.

[bob g]

anybody got a real double blind, independent lab published test resuls
supporting the use of edta or any other magic powder extending the true life of well maintained batteries?

anyone?

no i don't care to hear anecdotal claims of success, the web is replete with such.

not hear to argue for or against this stuff's use, what i would like to see is some real data, done by a real test lab that is not affiliated with some body selling some magic elixir

bob g

[PaulJ]

  "His observation is that whether your are gentle with minimal discharge, or aggressive, the total amount of energy extracted doesn't vary much."

 So sizing a battery bank to be as small as reasonably possible could make economic sense? The smaller bank will wear out and need replacing faster, but overall costs will be no greater than shelling out for a large battery bank in the long term.
 In the short term less upfront capital is needed.
 If something drastic goes wrong with a large battery bank before its intended lifespan is over then you're worse off than with replacing many small battery banks over the years.

   Paul.

   (Off-grid 8 years with 24 hours worth of battery storage ).

[gww]

I haven't bought my battery bank yet but I do have about 5 lawn mowers and 5 cars and was thinking that as many batteries as I have go bad, I might try adding the sulfite before I trade them in for core charge.  Didn't mean to take over the original post.  I find it all interesting.  Does 40% discharge seem to be a fair ideal for good use but not abuse in the overall picture?  Surely their is a point in the oridginal post that goes beyond, hi or low discharge, that hurts more then equal amounts of power compared to time.  What is really bad and should not be done?
Thanks
gww

[bob g]

according to sandia labs test results the optimum charge/discharge regime
for a flooded lead acid battery is known as the 50/80 regime

wherein you discharge to 50% soc, then recharge to 80% soc, cycling
within this region for 7 to 10 days, on the last day you recharge to 100%

the result is more kwatt/hrs output over the batteries lifespan and the highest charge efficiency which equates to lowest fuel costs if you are using an engine drive generator to recharge them with.

they did exhaustive testing to come to this conclusion and it has long been a regime i have promoted, for any installation that relies on an engine generator to recharge a significant amount of the time. also it is well documented that you get the most bang for your dollar invested in the battery bank, as measured in kw/hrs over the life of the battery bank, no matter what the charging source is.

bob g

[gww]

Bob g
I never understood what 50/80 ment.  That is exactly what I was asking.  I don't have a generator but can use the grid in an emergency.
Thank you
gww

Ps
What is the best rule of thumb way to tell battery charge/ discharge state?

[bob g]

the defacto standard for determining state of charge for lead acid batteries is to test the specific gravity of the cell after it has rested for 24hours.  this generally applies best after a recharge for determining if the battery is truly fully charged... and also after a discharge cycle that is pretty hard.  everything needs to settle down and stabilize before  you can get an accurate specific gravity reading.

now if the battery has been on a very low discharge path over several hours, you can check the specific gravity after a much shorter rest period and get very accurate determination of the state of charge.

there are those that will swear and claim that voltage is a good indicator of state of charge.... to that i say "whoey" (nicer word than bull$#|+)  a badly sulfated battery will still come up to what is indicated as a full charged battery, but the capacity clearly is not there.

this is not to say you can't use voltage as an indicator of state of charge, however you still need to have the battery rest for a period before the numbers are useful and any surface charge after a recharge will need to be removed.  having said that you can use voltage as an indicator only if you use it hand in hand with specific gravity checks and a good log book....

i would have no problems using a volt reading for state of charge, provided that periodically the specific gravity checks prove the battery is in good condition and has been fully recharged with some regularity, and equalization done when needed.

for agm and gel cells we are stuck with using a volt reading for state of charge, then we need to remember it is a relative reading and not a cast in stone exact state of charge indicator,,

too many factors can shift a volt reading and give an erroneous indication of state of charge.

with agm and gel cells, i would certainly only depend on voltage if the battery has been properly recharged and is showing no signs of capacity degradation.

in my opinion capacity testing ought to be done probably 4 times over the expected lifespan of the battery.  draining a battery to get a reading on maximum capacity shortens lifespan of a battery, so therefore i would only do it 4 times over the life of the battery...  we need to do it then to get a true idea of the condition of the battery so that corrective action might be taken before things get to far gone to reverse.

fwiw

bob g

[ChrisOlson]

wherein you discharge to 50% soc, then recharge to 80% soc, cycling
within this region for 7 to 10 days, on the last day you recharge to 100%

Charging to only 80% SOC saves on water use and gives higher charging efficiency.  That last 20% is what makes the heat, uses the water, and gives a wider gap between measured input kWh to the bank vs measured out.

Rolls also recommends deep discharging the batteries every 3 months or so to improve performance because it opens up new reaction sites in the plates.  I've seen some folks claim that if you pull a battery below 50% SOC that it causes irreversible damage to the battery.  Well, maybe for automotive starting batteries that might be the case.  But Rolls' recommendations seems to counter that old wive's tale for deep cycle type.
--
Chris

[ghurd]

 So sizing a battery bank to be as small as reasonably possible could make economic sense? The smaller bank will wear out and need replacing faster, but overall costs will be no greater than shelling out for a large battery bank in the long term.

So where do we find a ~52.5AH 12V battery that is similar in $/AH to a pair of generic T-105s?
AND that will last as long?

It is not as straight forward as it seems.  Many other factors come into play, such as the Peukert Effect,...

anybody got a real double blind, independent lab published test resuls
supporting the use of edta or any other magic powder extending the true life of well maintained batteries?

anyone?

no i don't care to hear anecdotal claims of success, the web is replete with such.

AH to AH?

I can tell you a pair of Sam's Club 6V batteries last a lot longer than a pair of similar capacity pair of 12V boat batteries. (both pairs being about ~210AH at 12V)
Expected, from previous experience, the 12V boat batteries would last maybe a year, 18 months at best.
The 6V batteries were more abused, the oldest pair is about a decade old.  And they still work.

No goop was added to any of the 6V or 12V batteries.

IMHO, AH to AH, a battery built for the intended purpose will work better.
And there is a sweet spot for service life vs AH vs cost, which depends on the service it is abused by.
bob g - You knew that.

[BillBlake]

I don't think that any of them ever had it right so far. The Sandia Lost Bigtime Battery Studies
and common sense tells us that keeping Lead Acid Batteries charged up as much as possible
and as often as possible is going to lead to big dividends.

Other Sandia studies did indeed-ie show us how deadly that last piece of 'Finish Charging' is to
the total charging efficiency and

how people can be fighting their own game - like pis--ng into the wind or tugging on
Superman's Cape :-)

The 'Round-trip' Battery Efficiency and the DOD is going to depend a lot on just what type of
battery it is and runs deeper than we need to go here.

However with the price of batteries and transportation going Up so fast - in a way who cares.

Maximum Life Cycles (within reason) is going to be paramount to many people so 50% DOD is
out of the question for many unless they really had to do it.

The problem never was Sandia's heavenly advice but may be how we scheme or the lack
of putting a good scheming on the problem.

Does anyone care to comment on new charging schemes instead of so much concern about
the batteries themselves? Wild ideas are OK. We are just exploring ideas until proven otherwise.


Bill Blake

[PaulJ]

 So sizing a battery bank to be as small as reasonably possible could make economic sense? The smaller bank will wear out and need replacing faster, but overall costs will be no greater than shelling out for a large battery bank in the long term.

So where do we find a ~52.5AH 12V battery that is similar in $/AH to a pair of generic T-105s?
AND that will last as long?

It is not as straight forward as it seems.  Many other factors come into play, such as the Peukert Effect,...

 I was thinking more of battery banks big enough for an off-grid house. At smaller sizes the economics no doubt change.

 We have 500Ah(nominal) @48V and have been told by a professional installer that this is way too small as it won't last us 3 days of no sun or wind.
 The worst case scenario in practice has been running the generator for an hour or two 3 or 4 nights a week in the depths of winter leading me to believe that our "small" bank is the sensible option.
 I don't like pulling them down more than 25%, giving us about 6kWh effective storage.

 Paul.

[BillBlake]

If you chart the rapid drop in capacity of the undersized battery bank in comparison to a
pampered battery bank - then price out the units of power
(you pick a power label) 

it's cheaper per unit to pamper them.

It's Time X Capacity = Cost

Not cost + cost + cost will = the same cost.

Nor time + time with a lot of aggravation, transportation, travel time, generator time, etc.
done 2 or 3 times is the same thing as once with care.

The escalating price of generator fuel and other generator concerns has always been a problem.

It's going to cost one way or the other - no doubt.
It just depends on how much work and hassle a person can handle and how much they
want to be a victim of ever rising battery, fuel costs and Lost time.
Unless they have to bare budget the project which opens up another topic.


Bill Blake

[gww]

Bob g and every body else,
So lets go with the sams club batteries for now.   Knowing that I need to take specific gravity checks every so often,   I have and outback system.  To set it up, what voltage values would I set to represent. 
1.  100% charge.
2.  80% charge.
3.  50%  charge.
What would be the,
1.  low voltage cut off = 50%
2.  daily bulk- float charge = 80%+
3.  weekly  full charge regiment  100% charge.

What voltages represent these values and is it the time in bulk that gives the 100% charge?
Does my question even make sence and is it understandable?
I wellcome any help.
Thank you
gww

[bob g]

the point of my post was how to get the most kw/hrs out of a bank, which is not the same thing as getting maximum lifespan out of them.

i think folks get so caught up in wanting to get the maximum lifespan out of a battery that they end up spending enough on charging schemes over that lifespan to more than pay for 2 if not 3 sets of batteries in fuel burned to keep them charged.

now if one has enough solar capacity to keep a battery fully charged, lightly cycling the battery bank, then yes it is possible to get a long life out of the battery and also do it without spending a lot on fuel,, however the cost of the excess amount of panels must be factored in along with the excessive size of battery bank to allow for short cycling.

bottom line is this, there is no correct answer that it going to fit every application!  however not understanding things like how sandia labs test was done, what the results mean, and without doing a fair amount of comparative analysis, which includes a site specific understanding of both loads and generation capacities, there is no way to say with any certainty which way is better than another... all things considered.

i know a lot of folks that have 10 grand in battery banks, that are so knotted up with trying to extend their investment to a lifespan measured in decades that they are spending huge amounts of money on fuel to burn in a generator to keep the batteries fully charged and/or have added very large expanses of panels, wind generators etc all in an effort to keep from taking more than 20% off the top of the battery bank at "any" time...

this attitude/scheme on close examination and analysis can almost always be demonstrated as being much more costly than simply using the battery bank in a more efficient manner.

the thing is, once one buys into the idea that he must get 20 years out of his battery bank, and has invested in all those extra panels and extra wind capacity, extra generation capacity and paid a substantial amount of money for fuel he has burned,,, it is very hard to back away and admit that perhaps he should have done a complete analysis before hand and done a bit more study.

it does seem counter intuitive on taking a recommendation, then having spent a rather large amount of money on a battery bank to use them in a manner that will likely consume them in half the time that one "might" get if he short cycles them and pampers them, to find out that yes it might well be better/less costly to use them rather than pamper them.

batteries need to be viewed as a consumable and as such one should determine how to optimize their usage in order to get the most out for the investment,, most out does not necessarily and rarely is equal to most lifespan.

much like an expensive gallon of barn paint, what good does it do one  spend the labor to spread it on so thinly in an effort to get maximum coverage if in the end it is barely covering (taking twice as long) and leaving large thin spots?  far better to use the paint as designed and get half the coverage in sq/ft , spending half the labor and have it done right.  or so it would seem

going back to answer Ghurd,,, yes i knew that.

my point of my response was not to agree with the claims of the OP report, because i don't agree with the report. after having read the report it is not clear to me that the author fully appreciates or takes into account anything other than maximizing the lifespan of a battery, vs using the crap out of it, as applied to electric automotive applications...

bob g

[bob g]

gww

the following is my opinion only

first of all i don't commit to memory specific's that i can look up, things like voltages at differing states of charge, the reason being i have no idea what inverter/charge you have?  you state an outback but i have no idea of what system voltage. 12, 24 or 48?

lets make some assumptions for the sake of discussion, lets pick on a 12 volt system

this would require at a minimum 2 of the sam's club golf cart batteries at 6volts each

iirc a fully charged 6 volt is 6.7volts, lets assume that for discussion
(however look it up to make sure)

lets also assume that a 50% state of charge battery after having rested for several hours indicates 6.4 volts

and lets also assume that at 80% the voltage is 6.55volts

(again check a chart to be sure) 

there are also charts that show states of charge at differing levels of specific gravity (temperature compensated)

the first thing to do is get both charts from the manufacture or from one that makes a battery of similar construction.

the second thing to do is setup a log book and list each cell

then fully recharge the battery at the recommended voltage until such time that there is no further increase in specific gravity, remove the surface charge and then let it rest overnight... recheck the specific gravity and check the voltage,,, log both in the book

this will be our baseline for a fully charge battery, 100% recharged.

then calculate the amp/hrs it will take to reduce the charge to 80%
and do so, let is rest overnight and recheck both specific gravity and voltage... see if the numbers come fairly close to the published chart numbers,,, they should provided you don't discharge at a high rate.
if the numbers look similar to those of the published chart then you know what the voltage is at 80% state of charge.

continue to discharge to 50%, let it rest overnight, recheck the specific gravity and voltage, compare to the published chart and if it is close then you know that what the voltage is at 50%state of charge.

now you can program your inverter/charger based on these numbers

periodically go back, with your log book, check the voltage of the battery after a period of rest (overnight is best, keep it similar to your original rest period) if the battery shows the same voltage as it did in your original test for 50% then we would expect the specific gravity to also match the original test results... if there is a mismatch (which will generally always be indicated as a lower specific gravity) then we know we should fully recharge and probably do an equalization, most especially if there is a difference between cells..

what you want to determine is this, you want to first determine exactly what voltage correlates to what state of charge, and then program accordingly. then verify this periodically while you are doing system maintenance and logging each cell anyway.

the goal is to learn if the charging regime is appropriate for complete recharge frequently enough to keep normal sulfation converted and not allow it to crystallize and harden... the only way i know to do this with any certainty is with a logbook, hydrometer, and a consistent test protocol.  if after a few log checks you find the numbers indicate that things are not up to snuff you can tweak the programming to accept a higher voltage number that correlates to a specific state of charge.

at some point you may find that 6.44 instead of 6.4 is 50% state of charge for your battery bank, and can then reprogram your inverter charger to this number and in doing so have a better chance of knowing whether you are keeping to no more than a 50% state of charge as a low point... if that is what you want of course.

make sense?

bob g

[bob g]

i would like to add a couple more points if i may

i have also seen folks that are so anal about short cycling that they neglect to consider the needs of the battery to get the electrolyte stirred up... it sits there basically on float for long periods of time, the owner thinking "hey wow, i will be getting 20 years out of these" when the reality is the electrolyte is stratified and eating the bottoms off the plates!

then there is as Chris alluded to, you gotta work them once in a while in order to get more reaction sites opened up in the plates.

working the batteries with the 50/80 regime accomplishes both, it gets the battery working enough to keep the electrolyte from stratifying, and opens up new reaction sites on the plates.

bob g

[ChrisOlson]

I got a pair of 95 AH boat batteries that are 9 years old this coming spring.  I have used them in the boat in the summer time, and every winter since they were new they have been pulled out of the boat and hooked in my big battery bank and get the snot worked out of them every single day.  Those batteries powered my trolling motor, electronics and lighting in the boat again this summer and can't really tell the difference between them and new ones.

I don't know how long they're going to last, but they have not been treated gentle or shallow cycled for their entire lives.
--
Chris

[BillBlake]

i would like to add a couple more points if i may

i have also seen folks that are so anal about short cycling that they neglect to consider the needs of the battery to get the electrolyte stirred up... it sits there basically on float for long periods of time, the owner thinking "hey wow, i will be getting 20 years out of these" when the reality is the electrolyte is stratified and eating the bottoms off the plates!

then there is as Chris alluded to, you gotta work them once in a while in order to get more reaction sites opened up in the plates.

working the batteries with the 50/80 regime accomplishes both, it gets the battery working enough to keep the electrolyte from stratifying, and opens up new reaction sites on the plates.

bob g

bob g,

Yes, I agree that it's good to 'Long-stroke' your batteries once in a while.
(Run them down to 50% DOD - or so.)

Who said that you can't Gas your batteries as needed to avoid stratification.

Of course the Legendary Sandia National Labs has a real good paper (including photo's)
on that battery subject as well.

Yes, noisy Generator Fuel is evil. Let's think NEW instead of old news and scheme to
eliminate most ALL of that Fuel while still Constantly Pampering our batteries.

Let's coolly get a calculator out and start adding up the years, the fuel, the oil, the noise,
the hassle, the neighborhood alert system - hey Look at me -
the expense replacing generator's, etc.

We could call it 'The OtherPower Theory and Scheme of Battery-tivity'.

Also 'Battery / Fuel Inflation Insurance'.

We also need the proper Level of Fanfare for this 'Group of Groups'.   
 
If I had a group of batteries that were Not being sucked on all the time (like a house bank)

and they had 2, 3 or even 4 days to get charged up real nice and sweet using Solar Panels -

how much of a difference would this make instead of sucking on them all the time but

expecting dem to somehow get fully charged in a Hurry - anyway?

Could I even probably use Less Solar Panels on this one group of batteries than a group that

only got the benefit of a single day (or short day) of Sun (or a lack of sun) and then get Sucked

On and off of - ANYWAY?

In this Life and Death Scheme that has always been?

We are Leading up to something but are slowly setting our minds free from the old as we go.

Like I said it's going to cost anyway you go. Might as well quit fighting it and play to win.


Bill Blake

[bob g]

Bill,, respectfully...

i have no clue half the time what the heck you are talking about!
and the other half the time i fear that i am not sure that i understand
what you are talking about!

please speak in plain english and leave out the flowery prose.

it makes it much easier to follow your logic.

let me clarify my position

1. i have no problem with batteries being babied and pampered and having them last 20 years or more,  however the return in kw/hours will be no greater than any other scheme, and from research it has been proven the inverse is true... while you will get longer life you will get far less kw/hrs out of them.

2. i am not anti generator, quite the contrary, i am very pro generator, provided it is done correctly and the heat is recovered, "and" used to offset heat that would have been provided by other fuel supplied needs.

3. it is a very rare installation that can get by without a generator, therefore a generator is at worst a necessary evil, so my position is applying it in a responsible manner.  rather than look at it an evil, one should embrace it as a working part of a system and optimize its operation so that maximum efficiency is attained.

4. batteries are also a part of a system and should be used as efficiently and effectively as possible. they as are every other part of a system are a consumable. as a consumable one should learn how best to get the best out of that consumable... having them last 20 years may not be the best use of that consumable when all things are considered.

the overall view is this

we have a system, the system includes different subsystems, and each subsystem has parts.

the system is complete with power generation, power storage, power conversion and power usage (loads).  everything needs to be optimized to work together to get maximum efficiency and best ROI(return on investment).   to focus on any specific subsystem or worse any specific part of a subsystem to the exclusion of how it inter relates to other parts of either the sub or system is likely to end up costing more money than one would expect or provide a much lower ROI than projected or worse a complete failure of the project to do what it was designed to do.

one must factor in not only his capital investment but his labor investment over the life of the system. being realistic about his labor costs are generally badly underestimated or neglected altogether.

for instance and as an example, what good does it do to not include ones labor into the calculations when it comes to battery maintenance? maybe he thinks it is not a problem and he enjoys doing it, pampering and babying them, and all is good. then what happens 2, 5 or 10 years down the road when he is out of town or sick and another family member must take over these responsibilities?  maybe that person doesn't see it as an enjoyable hobby and doesn't do the necessary babying or pampering? then what?

we can go on, however it probably is not worth the effort, those that understand, of course understand what i am saying, those that don't understand likely never will.  and that is ok with me.

it all comes down to a difference in design philosophies.

bob g

[gww]

Bob g
I am fine with opinions as I know they come with 10 or more years of thinking and doing on this subject.  I did look for the manufacturing specifications for a whole day.  I believe johnson controls make sams batts.  The amazing thing is I can't even remember if I found a chart or not.  I found several but I was to dumb to save it so now I get to do it again.  I didn't think my memory would get this bad as I got older.  I thank you for laying it out for me.  If I can make myself do half of it I am sure I will be ahead.

Chris
I know you also are speaking, after doing, and as you keep helping me understand more all the time, I might avoid mastakes.  I would have never thought it would be as intricate and overwelming to learn this stuff when I started trying to build tubines from junk and solar panels in a spare bedroom.  I was just bored.  I had no clue and still don't but am progressing.

Bill
Thanks for answering my private message on the batteries from you post.  The above guys have quite a bit of an investment in me.  I was dumber before they chimed in.  Even they didn't always come from exactly the same platform as each other in every instance.  They are well versed and very helpfull as you showed yourself to be when you took the time to answer my message.

I figure I will screw myself due to lazyness,  forgetfullness and lack of knowlage.  I exspect this as I am doing it myself and not hiring an exspert to do it for me.  I can't believe the members on this site who give their expertise giving me a chance of possible sucsess.  Thanks for taking the time to answer my questions.
gww

[bob g]

check out this attachment, it might be useful to you

bob g

[BillBlake]

Bob g
I am fine with opinions as I know they come with 10 or more years of thinking and doing on this subject.  I did look for the manufacturing specifications for a whole day.  I believe johnson controls make sams batts.  The amazing thing is I can't even remember if I found a chart or not.  I found several but I was to dumb to save it so now I get to do it again.  I didn't think my memory would get this bad as I got older.  I thank you for laying it out for me.  If I can make myself do half of it I am sure I will be ahead.

Chris
I know you also are speaking, after doing, and as you keep helping me understand more all the time, I might avoid mastakes.  I would have never thought it would be as intricate and overwelming to learn this stuff when I started trying to build tubines from junk and solar panels in a spare bedroom.  I was just bored.  I had no clue and still don't but am progressing.

Bill
Thanks for answering my private message on the batteries from you post.  The above guys have quite a bit of an investment in me.  I was dumber before they chimed in.  Even they didn't always come from exactly the same platform as each other in every instance.  They are well versed and very helpfull as you showed yourself to be when you took the time to answer my message.

I figure I will screw myself due to lazyness,  forgetfullness and lack of knowlage.  I exspect this as I am doing it myself and not hiring an exspert to do it for me.  I can't believe the members on this site who give their expertise giving me a chance of possible sucsess.  Thanks for taking the time to answer my questions.
gww

gww,

I like simple but drastic and effective solutions. They can take years if not decades of thought,
experiments and experience. Then the answer many times is anti-climatic and people may say
"is that all there is".

Hence a person can elect to propose the answer to the riddle or riddles in stages.
Perhaps with a few building blocks of thought. Today I spoke of using more than a
single day to charge a 'special' battery bank and perhaps not needing as many Solar Panels
as normal. Also NO sucking on this bank. It's left alone for 2, 3 or 4 days to do it's charging thing.

Why? We are not at that Block yet and unless Bruce or one of the other Mods holler at me
I'll determine the timing. It needs to be fun and to just blurt out what I have to say skipping
to the end would ruin the fun.

With the Ni-Fe Batteries I never made it a secret that I was still learning as we all were going along.
The 'mugs' as I call them, John Mario D'Angelo and Brandon Williams keep whining off list to people about
my experience (or lack of) with actual Ni-Fe Cells.

Actually I had Russian Ni-Fe Cells for a Radio (37.5 Amp Hour I believe ) Decades before either one of them
and their ACTUAL Extremely Limited hands on experience with Ni-Fe cells.
All in THEIR writing but it is really a Ni-Fe post - not for this thread.

Just like my first good taste of living off-grid, on my own, was over 45 years ago so I never feel the urge to
say well I got dis and I got dat. In my world what I have and where I have it stays with me
and my little gang.

Several examples of simple solutions of the past where nobody says a word as to - hey that's good or
hey kiss my a-s - come to mind.
One was when a number of great minds from around the world were all going through changes and going
on and on and on about wanting to burn Vegetable Oil like it was Kerosene.

I already had invented the worlds most cost effective Survival / Light Stove that ever was,
is now or ever will be.
Most of the plans had been given away. So why not straighten the Veggie Oil deal out as well
and make it fly right? So I did.

In both cases the solution is very effective but very anti-climatic using existing OLD technology
with a simple new twist or two.

Sometimes a little fanfare and drum roll may be in order if the answer is going to be
simple enough but work real good.

In this battery charging case there are a few battery principals at work.
Number one in the revolutionary

'OtherPower Theory and Scheme of Battery-tivity'

was simply laid out today. The first building block to a new understanding of time and results.

Google seems to be spreading some BillBlake stuff around pretty good so someone must
understand a little of it and be having a little fun as well.

To be continued as fun permits. 


Bill Blake

[gww]

Bob g
Thanks for the chart you probly saved me a day of looking.   I do have anouther two part question;
1.  how often do you suggest periodic maintenance?
2.  what is the longest between checks before I am really flirting with disastor?
Thanks
gww

Bill
I'm not worried about anticlimax, its the climaxes that scare the heck out of me. 

[bob g]

GWW

you will probably get as many answers to these two questions as there are responders to them.

my opinion only, ymmv and all that.

1. how often?  that really depends on your usage, charging capability, cycles, temperature and a few other factors, however as a general rule

i would recommend doing the first log entry as earlier described, then do a couple dozen discharge/charge cycles to at least 50% state of charge followed by a complete recharge and then recheck and log the info in your logbook... maybe that takes place about 2weeks after installation and they are working.  then i would repeat the test and log at 30 days later, then again in another 30 days,,, if at that time everything appears to be working as normal, water usage is such that you can extend out to 60 days, they i would do so... recheck and log 60days later,, and then again on 60day intervals until such time that you have evidence that you could safely extend another 30 days... ending with a 90 day cycle...

you might well have others tell you that every 6 months is enough, but for me i would not go over 90 days, unless my usage is very level over time and i had long term data indicating that water usage was such that i could extend further... however for me going over 90days without servicing the bank, adding water, cleaning terminals, checking specific gravity, doing equalization, and logging the results, probably would never happen... 90 days is a stretch in my opinion unless the batteries are exceptional quality such as the 5000 series rolls/surrette batteries, even then i would be too nervous not to keep a close eye on them.

meanwhile i would do periodic checks of battery voltage, much like Chris is doing,  not so much to determine state of charge but to determine if there is any string imbalance issues that i need to get involved with.

2. what is the longest without flirting with disaster?  no real answer here either, it is system and use dependent, as well as quality of battery. you might well end up flirting with disaster at 60 days, then again you might be safe out to 6 months?  then again on a system that is under heavy use, you might get into trouble if you don't check on them every month?

the only way to know is by empirical evidence over time with the batteries you plan to use, powering the loads you intend to power, recharging with the system you plan on using... basically no way to answer that until you put the system in place and start to monitor its progress.

3 things can take place without checking, testing, logging the battery under your usage and charging..

1. it can be undercharging, which will allow sulfation to harden and the loss of capacity being the result... so you don't want to go too long early on doing the testing and logging

2. it can be charged properly, and all will be good, this is the optimal goal, or

3. it can be overcharging, and boiling away water, overheating the batteries, with a reduction of lifespan the result

obviously our goal is number 2, and we want to avoid number 1 and 3 like the plague.  only way to assure #2 and avoid #1 and #3 is to do the periodic maintenance, testing and logging of the batteries, and adjust accordingly if needed.

hope that helps
bob g

[ChrisOlson]

90 days is a stretch in my opinion unless the batteries are exceptional quality such as the 5000 series rolls/surrette batteries, even then i would be too nervous not to keep a close eye on them.

Our Surrettes need water once a month in hot weather.  In winter when they're colder they hardly use any at all even though the absorb voltage is up around 31.0 volts (24 volt system) most of the time.
--
Chris

[bob g]

thanks Chris

well there you go, this is exactly why its so hard to make a recommendation on periodic maintenance.... sure as you tell someone
that checking them every 60 days, you get a hot summer and a working set of batteries and find them to be drying out.

no substitute for experience, and no way to get that without doing it, using the batteries and in the type of service they will be run in.

best to be safe at first and over check them, which doesn't hurt anything than to put it off and find you have problems that could have been avoided.

bob g

[birdhouse]

i check my 24v (450Ah) system every time i'm at my ranch (vacation place).  mostly i just check for water levels.  and top off with distilled water as needed.  i've found, like chris, that hot summers require more water.  though winter almost never needs it.  i equalize about once every 1-2 months. 

on voltage, i check every battery every few months during the night under load, to see if one is lagging.  so far so good.

a note on the morningstar ts-60...  if in "pwm" mode, it can be set to the battery specs, but once put in divert mode, it seems to run the batteries harder, and use a lot of water, so i backed mine down in voltage max one notch.

i'm probably pretty bad at battery maint, but i don't draw them deep, and have professionally crimped interconnects with ani-ox on the terminals, thus i don't worry about them too much.  i use them hard at times because that's what they're there for, and am hoping for ten years from the bank.   if they last eight years, that's fine.  time for new ones. 

i rarely run a genset to charge the bank, but have done so a handfull of times.

right now i'm at 2.25 of a year, and they still act like new. 

adam

[BillBlake]

Of course we all know that the flesh can be weak. Same with theory and speculation without
extensive testing and verified reports. That's why many people were so disappointed when the
Legendary Sandia

'PV HYBRID BATTERY TESTS ON L-16 BATTERIES'

AKA 'Lost Bigtime Battery Studies'

https://www.google.com/#hl=en&sugexp=les%3B&gs_nf=1&tok=e6xYuMDiEbaYPpXb9WVYlg&cp=28&gs_id=4&xhr=t&q=Lost+Bigtime+Battery+Studies&pf=p&output=search&sclient=psy-ab&oq=Lost+Bigtime+Battery+Studies&gs_l=&pbx=1&bav=on.2,or.r_gc.r_pw.r_cp.r_qf.&fp=df7f322f36a8afd9&biw=1011&bih=526

http://search.yahoo.com/search;_ylt=AiM9GDGP2I2aGAtU9lq9RCqbvZx4?p=Lost+Bigtime+Battery+Studies&toggle=1&cop=mss&ei=UTF-8&fr=yfp-t-701

(that outfits like the Legendary Morningstar Corporation thought so highly of)

just evaporated off the face of the earth for well over a Decade.

Then 'The Boys' got a little taste of it for a few weeks and it completely disappears again.

Now that report was exactly up the alley of what is getting thrown around in this thread.

Sandia has tried a lot of things and they have had to shut down experiments in mid-stream
so they would not ruin good batteries with foolishness.

Where I'm heading is EXACTLY 'In Tune' with their findings. Not 'going off' in new frontiers.

Just NEW thinking to achieve the preferred results ('hot set-up') without much (if any) fuel.

I have to ask who made copies of this Landmark 8 page Study for 'the boys'.
Who was thinking ahead and showed a little humility.

<snip>

Summary

While the L-16 is a very good candidate for
use in PV systems, results of the PV Hybrid
Test Procedure indicate several ways that the
L-16's performance can be enhanced. The
first set of test results were obtained with 12
volt batteries (that is, two L-16's in series).
The purpose of this test procedure was to
characterize charging profiles in a generic PV
hybrid cycle.

Results show that the L-16
battery can quickly lose as much as 48% of its
initial available capacity if the regulation
voltage is too low, the time at regulation
voltage is too short, and the time between the
finish-charges is too long.


The data in this
report suggest the following:

(1) L-16 regulation voltage in PV hybrids
should be well above 2.40 vpc (14.40
volts) and may need to be as high as
2.55 vpc or higher (15.3 volts for a 12
volt battery) depending on how the
battery is charged.

(2) L-16 finish-charge time in PV hybrids
should be at least 3 hours and may need
to be longer depending on the time
between finish-charges.

(3) The maximum interval between L-16
finish-charges should be about one
week.

(4) Results vary significantly for different
manufacturers.

The 12-volt testing was followed by 48-volt
battery string tests that demonstrate how weak
or low capacity cells will function within the
24-cell string.

Further, results show the need
for proper charge control and regular
inspections. This test identified a low capacity
cell that was forced into reversal on discharge.
A cell in reversal will eventually be damaged
and require replacement. Additionally, the 48-
volt battery string test provides information on
how specific gravity measurements, monoblock
(a monoblock is the smallest packaged battery
size – three cells or six volts in the case of an
L-16 battery) voltages, can be used to track
battery health. Implementation of these
procedures can help ensure that the L-16 will
achieve its maximum cycle-life and thus
minimum life-cycle cost.

INTRODUCTION

<end of snip>

Bill Blake