Ni-Fe battery

[smidy]

Hello, Today I started hauling some batterys from work (recykling company) what i think is Ni-Fe. I have no history on them other than the scrap company we sell batterys for recykling rejekted them. this is how they look, this is about 1/3 of all that is avaible. So if anybody is sitting on know how and have experiance whit this type of battery please fill me in! (I hope you anderstand my baaaad english....)

[SteveCH]

If you have some NiFe batteries, you are fortunate. I think. In any case, look down several back posts from yours to this one:     Solar version Nickel-Iron battery specs ... released Oct 16 2010  and click on it. There have been a couple of discussion of NiFe batteries here lately, on this forum. You can also go to www.nickel-iron-battery.com and have a read.

[thirteen]

what voltage are they reading? Might be a great find. There should be a tag or something printed on a couple of them I would try and  separate a couple of them and look> Just an idea

[Ungrounded Lightning Rod]

Five cells per unit looks like 1.2V per cell for a nominal 6V battery.  That would be consistent with either NiCad or Nickel-Iron.

[thefinis]

They are most likely nicad and the cad is the part they do not like. Should not be anything in the nife batteries that would get them rejected.

Finis

[smidy]

well i think they rejected them because they didnt know what it were, we sell our (car) batteries to a regual scrapdealer, and lead they know about, but these they had no clue about. it seams like they are from the swedish manufactor Waldemar Jungners, today saft ab and are probably Ni-Fe, they are pretty "new", made in 1984, not even 30 years old  thats no age for a Ni-Fe, i read about edison cells that was over 100 years and still in service  this will be very exithing, just hunt some time to play with them, i will update when i been playing with them.

[WindriderNM]

Put a piece of Ph paper in one of them to see if they acid or base Ni-fe be base. You should be able to get wide range ph paper at a drug store I think it is called Hydrozine paper

[PeterDe]

Smidy
Can you tell me if there are any stamped indents on the cover that might be a date or model code?  At first look at the picture I thought that were original Thomas Edison Ni-Fe cells, but the wooden case looks different.  At least it looks different than the ones that I have that are over 80 years old, and I just got these a few months back and have been experimenting on them.  So far every cell has responded to the instructions that Edison published almost 100 years ago.  If those cells are Nickel iron there is no reason that they can not last longer than you will be alive (unless you have not been born yet).  Are you sure they were made in 1984?

If they are Nickel Cadmium they also will respond to the exact same recovery procedures.  Obviously there are differences in the environmental implications cadmium or the iron but the recovery procedures are identical.  Please try to find a model number, and take a few more pictures and send to me, I am very interested.

Also I have a lot of friends at Saft and they are the ones that I turned to when I was trying to find out the codes that are stamped in the Edison cells that I have.  I tried the Thomas Edison museums and national park but could find nothing until I reached out to some people at Saft who sent my request on to others who actually had the old data.  Lucky me.

PeterDe

[Bruce S]

Smidy
Can you tell me if there are any stamped indents on the cover that might be a date or model code?  At first look at the picture I thought that were original Thomas Edison Ni-Fe cells, but the wooden case looks different.  At least it looks different than the ones that I have that are over 80 years old, and I just got these a few months back and have been experimenting on them.  So far every cell has responded to the instructions that Edison published almost 100 years ago.  If those cells are Nickel iron there is no reason that they can not last longer than you will be alive (unless you have not been born yet).  Are you sure they were made in 1984?

If they are Nickel Cadmium they also will respond to the exact same recovery procedures.  Obviously there are differences in the environmental implications cadmium or the iron but the recovery procedures are identical.  Please try to find a model number, and take a few more pictures and send to me, I am very interested.

Also I have a lot of friends at Saft and they are the ones that I turned to when I was trying to find out the codes that are stamped in the Edison cells that I have.  I tried the Thomas Edison museums and national park but could find nothing until I reached out to some people at Saft who sent my request on to others who actually had the old data.  Lucky me.

PeterDe

                                     Smidy: a quick apology to your post and this post, but this is somewhat relevant.

PeterDe;
IF you hadn't noticed, in this very area there was another who talked about NiFe batteries. He wasn't as nice and helpful about these types of batteries as you seem to be.
May I ask you to help us with these types?

I have done hours and hours of work using equipment both here at work and my hobby sized PV setup at home to see how the 1.2V NiCd based batteries could be best utilized and how well they could stand up to abuse.
It's no secret I have been popped a few of them due to too high a charge or trying to get them to hold me than they were rated for. All in the good name of knowledge mind you 

Would it be possible for you to expound on the charge discharge cycles of your current system using the NiFe batteries?
We are truly interested.

Many Thanks
Bruce S 
 

[jlt]

The ni-fe battery's i have have metal cases and are in wood housings that keep each separated the The metal case is hot. The ni cads I have use plastic cases.  To test to see if they are alkaline battery's put a teaspoon of baking soda on something and add e few drops of the electrolyte on to the soda if it fizzes they are acid battery's 

[Bruce S]

The ni-fe battery's i have have metal cases and are in wood housings that keep each separated the The metal case is hot. The ni cads I have use plastic cases.  To test to see if they are alkaline battery's put a teaspoon of baking soda on something and add e few drops of the electrolyte on to the soda if it fizzes they are acid battery's 

jlt:
I believe you to be correct on the NiFe batteries, I think from lots of old book readings, they case is Nickel plated.
Also very correct on getting a small drop of the electrolyte out and dropping some baking soda in it, fizz and it Acid.

good call
Larger NiCds tend to need being laid on their side so the fluid can migrate the entire length, NiFe(s) upright so the fluid doesn't spill.

Cheers
Bruce S
 

[smidy]

for PeterDe, I did try to take some pictures, no sucsess  I´m not able to get focus on the labels...but on topp of the cells there is 2 indents one on each side of the fillercap, on one side it is a c inside a romb, looks almost like a copyrigth c, and on the other side it is stamped hk-55. The sign of the metal frame is mostly in russian exept for 5-HK55 and 1984 witch i think mean 5*Hk55cells and made in 1984. I cuoldent resist, so i topp up 10 cells with water and charge them in series with a 12V charger for about 48h and let them rest for 24h they all read over 1.2V the best cell was 1.39V one was 1.22V  and the rest above 1.3v, and that is whit baaad elekrolyt i think, phu my english......bad...but i hope you get it anyway

[DamonHD]

Try the 'macro' (icon of a flower) setting on your camera if you have one.

Rgds

Damon

[Rabrsniver]

I believe your cells might be the Russian ones from:

http://akbkursk.ru/

The company is Accumkursk.

Unfortunately, most of their info is in Russian. I have tried emailing them without much success.

Maybe you'll have more luck!

[PeterDe]

Bruce S and all;

If I can help ANYONE with batteries by sharing what knowledge that I have learned over the years then I will be happy.  As for "popping" a few cells "all in the good name of knowledge", when we were initially trying to figure out how to recover the 2 volt VRLA cells and first trying to use the catalyst, which by the way is the Philadelphia Scientific Microcat, we blew up more cells then I really want to admit, and I am talking about ones that were typically 1000 - 1600AH cells.  These were not small.  I bet that we blew the tops off of at least 20 - 30 cells over 3 months of agressive experiments.  Of course the cells really did not cost us anything as they were ones that we had removed from service and were about to recycle.  This was before we had fully developed the IOVR process.  Way before it morphed into the IOVR+ process.  It was a very "interesting" time doing those experiments.  We had many of those "what the he** caused that" moments.  All in the quest for knowledge of course.

Smidy;  I am VERY INTERESTEd in helping you in any way possible.  But to do so we need to find out just exactly who manufactured them.  Keep trying with photos.  If it is Russian I can  get it translated by an old friend.  I also had tried to communicate with Kursk and got no reply either time, but I did not have my Russian born friend try, as it was just for my experiments.

With what you said about adding water and charging them and the results that you got, I have no doubt that they will recover.  To get the most capacity recovery you may need to change the electrolyte and run a couple cycles (discharge and recharges).  Can you measure one of the cells for me, length, width and height?  From the model number it "may" or may not be a 55 AH cell, and if possible weight one.  Have a happy new year all.  PeterDe

[PeterDe]

Smidy;

I think I found your battery on the Kursk web site.  It is under their stationary section and the picture on the site looks exactly like your batteries.  It shows a nickel cadmium battery model 5-KL55.  I was not able to find a 5-HK55 model. 

Even if it is a Nickel Cadmium not a Nickel Iron there is no reason that you can not get a lifetime out of it.

Their web site is http://en.accumulator.ru/factory/kursk/  and it is easy to look around.  Their main catagories are in English but all downloads that I looked at are in Russian.

Hope this helps.

PeterDe

[dnix71]

Hey PeterDe, the direct link to a picture and description is here:  http://en.accumulator.ru/variety/stationary/element.php?IBLOCK_ID=127&SECTION_ID=0&ELEMENT_ID=3326&back_url=/variety/stationary/index.php

The case is green in their picture, but the case style is unique (and Russian, functional but not exactly pretty).





The first NiCads I owned were SAFT, made in Georgia somewhere (USA not former Soviet Republic). They were well made. I think I still have one C cell left that works.

[dnix71]

Here is the Russian doc translated and converted to plain text: This was a pain to do. I used Soho online and Google translate online and then had to save the doc as a pdf to keep the English translation. If I saved as txt Google gave me the original Russian. I then copy/pasted the text after opening the converted pdf.

Batteries and alkaline batteries Nickel-cadmium prismatic open For the DC communications, emergency lighting and alarm systems, power low-voltage electric equipment, trams, trolleys and subway cars. Symbols: K - open nickel-cadmium prismatic rechargeable batteries; L - mode discharge (long); 55, 80, 125, 150 - Nominal Capacity (5), A? h; P - the battery in a plastic tank T - the location of the conclusions on the end side; And - the battery in a rubber bag. numbers before the letters - the number of series-connected batteries in the battery. Climatic performance have category 3 GOST 15150-69 for operation at an ambient temperature from minus 40 to plus 40 C. Design Battery is a block electrodes, consisting of positive and negative all season electrodes separated by a plastic frame separator. Block electrodes placed in a metal tank of rectangular shape and is insulated from it viniplastovymi gaskets. The tank is welded around the perimeter of the battery cover. On the walls of the tank has an edge in the form of corrugations, which increase the stiffness of the tank battery. At the tank end walls have two pins with which batteries are mounted in the battery cage through insulating sleeves. Batteries to L 125 are made in metal cans (such as with pins or a rubber boot) or in plastic bins. Tokootvod made using the Born, which are derived on the battery cover. The electrolyte in the batteries used solution of potassium hydroxide density 1,19-1,21 g / cm 3 with the addition (20 + 1) g / L lithium hydroxide. Batteries fitted with a sleeve stopper. Sleeve tube is triggered when the excess pressure inside the battery from 0,005 to 0,05 MPa (from 0,05 to 0,5 kg / cm 2). When you angle the battery on a 45 ° angle from its normal position (pin up) electrolyte spills and splashing during use. Batteries consist of four or five batteries connected in series in a circuit by means of steel plated jumpers. Batteries are supplied in a metal skeleton. Accumulators (batteries) are efficient at ambient temperatures from minus 40 to plus 40 C. Batteries are supplied preformatted consumer, without electrolyte in a discharged state. Operating time batteries - at least 1000 cycles (with a capacity of not less than 0.6 C 5 A / h). Battery capacity after 28 days of storage in a charged state under normal climatic conditions of the environment - not less than 0.5 C 5 A? h. Capacity battery charged at constant voltage: at 25 ° C stress (1,59-1,61) in - not less than 0.7 C 5 A? h; at 0 ° C stress (1,65-1,67) in - not less than 0.5 C 5 A? h; with negative (18 ± 2) ° C stress (1,73-1,76) in - not less than 0.4 C 5 A? h. , Battery, discharged at low ambient temperatures:

2 of 4
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with negative (18 ± 2) ° C - no less than 0.5 C 5 A? h; with negative (40 ± 2) ° C - no less than 0.2 C 5 A? h. Batteries and battery resistant to ambient relative humidity 98% at 25 ° C, vibration and single strikes. Specifications Product type Normative and technical documents Rated capacity,? h Rated voltage, V * Dimensions, mm, length, L width, B the height, H (max.) Weight, kg, no more no electrolyte with an electrolyte KL55 05743834-3482-005 - 01 TU 55 1,2 47h150h353 3,8 / 5,0 5KL55
5,88 319h170h392 21,6 / 27,6 KL80
80 1,2 47h150h353 4,3 / 5,7 4KL80
4,7 264h170h392 20,0 / 25,5 5KL80
5,88 319h170h392 24,1 / 31,1 KL125 (with pins)
125 1,2 68h150h353

3 of 4
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5,8 / 7,5 KL125 (in cover)
1,2 74h137h362 6,5 / 8,0 KL125R
1,2 74h137h353 5,9 / 7,4 4KL125
4,7 375h170h392 26,5 / 33,5 4KL125I
4,7 305h169h408 26,4 / 32,4 4KL125R
4,7 305h169h408 28,8 / 34,8 5KL125
5,88 458h170h392 32,6 / 40,7 5KL125I
5,88 379h169h408 35,8 / 43,3 5KL125R
.
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5,88 379h169h408 32,8 / 40,3 5KL125T
5,88 489h166h392 32,6 / 41,1 KL150
150 1,2 74h150h353 7,0 / 8,5 4KL150
4,7 375h170h392 29,5 / 37,5 5KL150
5,88 458h170h392 38,5 / 44,5 5KL150T
5,88 489h166h392 38,6 / 45,0 * The voltage of the batteries are inclusive of not more than 2% loss on the buses and bridges. Manufacturer's warranty Battery Dimensions Guaranteed shelf life of batteries in a discharged state - 2,5 years in storage conditions for group 2 (C) and 3.5 years in storage conditions for group 1 (A) the date of manufacture Guaranteed service life of batteries with the commissioning - 3 years. Guaranteed service life of batteries for export - 3 years from the date of commissioning, but no more than 3.5 years since prosledovaniya across national boundaries.

[PeterDe]

dnix71;   That is exactly the one I was referring to, and only because the frame/tray is so unique.  I agree with the functional but not pretty concept, but then "beauty is in the eye of the beholder".   When Smidy measures the ones he (or she) has the we all can figure out what AH they are.  

Saft still has a plant in Valdosta Georgia.  I have visited it a few times over the past 10 - 15 years with my most recent visit last summer when I toured their new assembly line for a new desgned cell.  Very amazing manufacturing process.  As soon as their new plant for Lithium Ion batteries is built and up and running near Jacksonville Florida I intend to wrangle an invitation for a tour of that.  I am lucky to be able to able to get the different manufacturers to give me tours of new things and I attribute their willingness to my history in the industry and my time on the IEEE battery working group, or maybe it is beacuse I buy them a lot of beer.  Who really knows ?

Earlier this morning I did go and read all of the previous posts regarding NiFe batteries as referred by Bruce S, as I had not read them before my first posts the other day.   I need some time to digest all that is said, and yes I have communicated quite a bit with Ian on my reasearch on the old Edison cells and yes they are over 80 years, and yes we were able to make them functional and by following the guidance as to sizing deration factors of IEEE 1115, and yes I am very impressed with them , and yes there are all sorts different ways to do things, I need time to put together a well thought out response to some of the statements on other posts, as not everything that I recall of my statements are as I remember them.  I think that there are just some misunderstanding of communications, or maybe how I made some statements.  I am doing a paper at BATTCON this year on what we discovered, the title of the paper is "Thomas Edison had it right" and it just explains what we did with these old cells that we got out of a remote site in the Adirondacks and how they recovered into useful cells.

[PeterDe]

dnix71;

Good job with the translation.  Thank you.

I "think" that waht Smidy has is a 55AH battery, probably at the 5 hour rate to about 1.1 or maybe 1.0 VPC, but not sure.  What I am sure of is that with everyone on this site, that we ought to be able to help.

Happy new year all.

PeterDe

[Rabrsniver]

Peter,

Since you seem to have the most experience with NiFe cells, I am hoping to pick your brain.

I have a bank of Chinese manufactured 600AH cells. Our system is 24V.

I am using 19 cells so the system will work with our Trace 4024 inverter/charger. The Trace charger has a maximum charge voltage of 32 as you probably know, so using 19 cells makes things work better.

3 of my original 20 have developed a problem. They seem to take a charge, but they use a LOT of water, and as they discharge, they "go negative." By this I mean that they go as low as -1.2V while the rest of the bank is at about +1V.

I have changed the electrolyte with no improvement. It appears they have developed a short? Do you think there is any hope to revive them?

Also, I have a bank of old 375AH Edisons. Although they are supposed to be from the late 40s or early 50s, they seem to be still chugging along. I do have a couple of them that don't seem to take a charge. Any help for these?

When I got the Edisons, the guy threw in 3 "weird" cells in rubber cases. I finally traced them down to Kusrsk, emailed them and got a reply - sort of. I asked them for info on what their cells cost, etc.

The reply I got was that these cells won't work with off-grid. (I am using 2 of them right now as replacements for my bad Chinese cells) I told them that I would like the info anyway.

After that I got no more responses, although I tried a few times. Perhaps some of the problem is the language barrier, or maybe they don't want to sell directly to consumers.

Anyway, I would appreciate any info you could provide as to how to revive my "bad" cells, if possible, and any charging regimes you recommend.

Thanks,
John

[smidy]

Now I been mesuring the batterys, the cells are h:200mm l:105mm w:48mm, The steelcase with 5 cells in it is l:3850 w:142mm h:250mm. I did also messure the voltage again, they all read over 1.3 volts now, strange sense one was 1.22V yesturday  , and they just ben sitting there, no charge or discharge, all I done is separating the steel case from eachother, mening it is 2 rows of 5 cells in series now insted of 10 cells in series that I had yesturday when mesuring. I did separate them for taking pictures on the russian sign on the steelcase, and then leve them separated, I will take new pictures when daugther arives home at thursday, she have a fancy camera, I only have (for a mobile phone) fancy mobilephone camera, wich i took the pictures on page one with, but no macro on the phone, so imposeble to get instamps on picture before thursday.... 

[PeterDe]

Rabrsniver;

I must emphasise that I do not hav ethe most experience with Ni-Fe as my 30+ years of hands on experience has been with lead acid and jsut a little with Ni-Cad with the exception of the past less than a year, with the the Thomas Edison cells that I have been playing with. Also I need to emphasize that I know just about nothing about solar panels, or wind generation, I am just a battery guy that would like to help anyone that I can if they can use my experiences in any way.  With that being said lets answer yoru questions if I can.

With the 3 cells, just to prove that there is a short, have you charged them and then let them set and measured the voltage to see how quickly their voltage decays?  Or have you tried using an infrared (if you ahve one) to see if there are any pin point hot spots in the cells?  Am I correct to assume that the batteries are from ChangHong, or from someone else?  What voltage do you try to charge them at?  Can you lower the voltage and over now and then us a high rate charge?  However if they are using water at a much faster rate, and go into reversal durign discharge it "sounds like" there is some sort of a breakdown inside of them.  Should show a hot spot, or just those cells get hotter during normal charge operation.  As a last resort if they were mine I would try dischargign them down to zerp volts, draining the electrolyte, filling them with water, shaking the hell out of them then drain the water, then filling with water, shake like heck again, and drain it then refill with electrolyte and try high rate charging.  If there is no improvement you will have tried everything that I would have, and it must be an internal breakdown of some kind. 

Kursk only will talk about using Ni_Fe for traction type uses, who knows why.  YES I think there is hope for the Edison's that will not hold a charge.  Same procedure as above, with the flushing and cycling.  I will attach the date codes for the Edison cells.  I wish I knew how to be able to insert more but my box is full.

[Rabrsniver]

Peter,

Thanks for getting back to me so quickly.

My Chinese cells are from "China Battery Center," not Changhong. I have tried various charging voltages, trying to find a happy medium between generator run time and discharge time - everywhere between 28.6 to 32 volts.
Its a trade-off of course. With a lower voltage the generator runs less, but the charge doesn't last as long. We do have solar panels and a microhydro, but of course when the sun doesn't shine, or the water isn't flowing we have to rely on the genny.

I am not where the batteries are right now, so I can't try to rinse them out and add new electrolyte.

Also I don't have the Edison serial numbers with me. I was told by the guy I got them from that they were first used on a ranch in Wyoming in the 50s. I got them from a guy in Idaho, so they've been around.

All I remember off-hand is that they are A10s, 375AH.

If you have any luck communicating with Kursk, please let me know. I personally think that their cells would work OK off-grid, since the guy I got them from used them that way, and so am I.

John

[PeterDe]

Rabrsniver;

I hope that someone will explain to me how to attach or post, or whatever it is called, a large document as I just tried to attach one of the Thomas Edison manuals and yes it was over 150 KB, and I ended up starting over.  Someone please let me know how to do that and then anyone can read them.  They are pretty educational.

I am not familiar with China Battery Center.  Also in talking with Ian a while back he said that he had tried to communicate with Kursk and they said that the Ni-Fe batteries were for traction and not stationary applications.  This sounds like a corporate decision to protect their different products in different market segments.  From a manufacturing position this makes sense.  But it does not mean "to me" that they cannot be used in any application that they will work in.  After all the original Edison cells worked in all applications, and in looking at the ChangHong plates, and from reading the Kursk literature on their cells and particularly the steel jars (cell container) it sure sounds like both are copies of the old Edison cells.

I only ask about the date codes on your Edison cells as I am trying to gather knowedge.    Have a great day.  PeterDe

[PeterDe]

All;

one thing that I forgot to mention is that during my investigations into the Thomas Edison cells I contacted Zapp from Montana since their advertisement says "made in america" and learned that what they do is to take old Edison cells and put them into new plastic jars.  I have no idea why they would do that since the Edison jars are darn near bullet proof.  The only reasonable reasons that I can think of are a) They want a larger electrolyte reservoir ??   or  b) They want the buyer to think they are getting a brand new cell (or do they tell the buyer just how old the plates are) ??  or c) They want to really clean up the plates, and have found it easier to use new jars.

I myself without any more knowledge about why any does anything, would put the plates back in the original jars.  Those steel jars have withstood the test of time, and I have to wonder just how long the plastics will hold up, and how they will react to very cold temperatures if they happen to freeze.

Smidy;

I did not mean to forget you.  From the dimensions that you measured it sure "appears" to be in the 50 - 60 AH range.  PeterDe

[DanG]

Glass does not meet impact resistance, ie: earthquake and accidents and storms - I'd hate to see several tons of Edison jars after a 7.5 earthquake toppled them over, even gently.

[bob g]

the last and only edison cells i saw were sure enough steel jars, however the were welded construction
so to get them apart for cleaning means cutting the jars apart somehow.

i suspect after doing so it is just easier to replace the jars with plastic ones than try to weld the original jars back together
with the kerf left between the cap and steel jar?

i wish i had access to those cells now, at the time i passed on them thinking they were lead acid and being that they
had been sitting outside in the weather, obviously dead as a door nail, date of manufacture 1960, i figured them to not even be
good quality scrap.

looking back they might have been interesting to play with.

also looking back they looked like one hell of a lot of work to play with, in the end is that really "play"?



bob g

[PeterDe]

DanG;

I guess I miss your point.  What part of these cells are glass? I will try and attach a picture of some of them.  The cases are all steel, and in one of the old Edison manuals it shows them repeatedly ramming a cart full of these against a brick wall and in another section it shows them raising a cell with a rope and then dropping it to the floor.

I cannot attach the picture because of its size.

Can someone tell me how to attach pictures or other large documents please.

PeterDe

[DanG]

Ya, okay - steel - glass, my bad. Nickle plated steel can't compete with plastics for low cost or plastics inert nature.

[thirteen]

Radrsniver I read your post and understand youhave a micro hydro and solar system. I am not sure of your need for both systems but I will need a duel system something like yours. I will not have enough solar during the winter but I have water. During the summer I do not have water but have I have the sun. What problems did you have putting the system together so they work together?  Not sure if this is the right place to put this.

[Rabrsniver]

Thirteen,

Our weather and water source means we hardly ever have both solar and hydro going at once, just like you seem to.

I have all my solar panels going through an Outback MX60.

My hydro is wired directly to the batteries with no controller. It just sends AC from the turgo to the battery room where it goes through transformers and bridge rectifiers.

Since the hydro is seasonal and at best only puts out about 250 watts I've never had a problem with it overcharging our batteries since we have a number of loads (fridge, freezer, etc) that are going all the time.

Also, NiFe batteries don't mind being overcharged, so even if the hydro did put out more than we needed, the batteries could take it. (I wish I had that problem sometimes!)

John

[isoutar]

Hi Peter

Thanks for the report on your work and the presentation at Batcon, which I am hoping to attend too.   I had left the forum here because a number of folk really believed I was telling a tall story when I spoke of NiFe cells.

My experiments have been interesting.    We had been leaving all our house lights on since the summer and when winter finally reached its peak on Dec 21 we were running out of power and there was no sun for 2 weeks.    So we started to conserve and we got through another week before the sun started.    All that time we were running on the bottom 20% of the battery power ... down to full discharge amost on  a daily basis.

The batteries reached a full charge when the sun started again after 2 days of sunlight.     I did a full discharge test and the battery delivered over 240 amp hours even though the best I could do last summer was just under 220 amp hours.   

Edison mentions in his work with the USA navy just before the first world war ... the batteries strangely enough will often take 2 to 4 years to reach their optimal performance.    I can see mine have improved since I abused them.

Peter ... is their a chemical explaination for this??   

Also another chemical mystery ...why is LiOH added.    I tried mine with and without Lithium and it made no difference on performance.     I have a whole set of 10 amp hour cells for experimentation.    Did I remember to send you some new cells for testing?

Thanks again for your comments and hope your presentation is well received at Batcon.

Ian Soutar