Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

BillBlake · June 2012

You have important differences between Edison Nickel-Iron Batteries and Chinese Ni-Fe.
Some obvious and some that are not so noticeable.
All of them seem to be very important. One change is that the Edison Cell - Positive and Negative Plates
were kept fastened together with a hardware system where the Negative and Positive Elements
could be separated for 'secret Ni-Fe service' if need be.

This is where your old timer accounts about cleaning the plates and if necessary even
reconditioning the Positive 'Nickel Matrix Material' located in the pockets of the
positive plates comes to play.
One expert that helped me calls it 'A Lost Art' that he learned in his youth and then forgot over
many decades of a long life. Nothing got Lost. Not a bit of it.
Why it took just a hobbyist (myself) that got hooked on debunking all the mystery, myths, fish wives tales,
jive and riddles about Ni-Fe - to re-discover what is really going on is beyond me. It wasn't quick and it
wasn't exactly an easy puzzle but it was a lot of fun.

Keep Iron Poisoning in your mind from here on out.
Notice I didn't say maybe, please, perhaps, (or so) or whatever - but just laid it out there raw and cool. 8)

Today the Chinese Ni-Fe Plates are welded to a current carrying bar so if you contaminate the
positive elements which is the Nickel Hydroxide (+ additives ?) (another post), your in big trouble
and your just out.
If it doesn't all rinse out with flushing (which I Highly doubt) then it's tough and you permanently lose capacity.

When it gets bad enough you have throwaways on your hands with a 20% Nickel content.
(See the Changhong Batteries MSDS). A major battery junk dealer on ebay
pays around 15 cents per pound for old Ni-Fe batteries. He's paying around 43 cents for common Lead Acid
batteries because though lead is cheaper it's in a much higher battery concentration.

Another major difference was going from the full metal cases (jars) to much more fragile
plastic cases. I feel that this may have been a huge mistake and may have a
major influence on the 'touchy' Ni-Fe Electrolyte. (another post) If you read the catalog called
'Changhong NF-S Series Nickel-Iron batteries for solar PV Application'

http://www.changhongbatteries.com/Nickel-lron(Ni-Fe)_c13_m2.2.1.html

they tell you to Look for around 3 years (or so) of total use at 80% DOD which is Much lower than what
the Rolls 5000 Series batteries have in them.
I believe the Rolls 5000 series looks like they have around 82% MORE Life Cycles at 80% DOD than
the Changhong Ni-Fe cells do. Around 58% more Cycles at 100% DOD.

The Changhong cells start to show an advantage over the Rolls once you get up to
a MUCH More Reasonable DOD. At 50% DOD (50% Dead) the 2 battery technologies are fairly even.

There are situations where a person may need to 'buy a good 5 to 7 years with an undersized, overworked,
battery bank. In that case it's best to call Northern Arizona Wind & Sun.
Ni-Fe is for when you really have it ALL together, have plenty95 of cash and Really know Exactly what
to expect. Or at least hope that you do. :grr
Plus we start buying the Ni-Fe cells directly from China someday unless a Reliable, honest player wants to
step up to the plate after

'The Ni-Fe Theory of Battery-tivity' has been revealed.

http://www.solar-electric.com/batteries.html

The Chinese Ni-Fe Cells Shine at 20% DOD with the life Cycle Chart jumping up
to over 23 years of good use.

You have an American Changhong reseller, Brandon Williams at Iron Edison Batteries advertising
that you can run the new Ni-Fe Batteries into the ground at 85% DOD
(85% Dead) on a daily basis.

http://us4.campaign-archive2.com/?u=d832c729f5703f36b225522d1&id=3b37379f9d

This will Destroy the expensive Ni-Fe Cells much Sooner rather than later. When you see a
Changhong Operators Manual (which the resellers have always withheld from you) (another post)
it gets explained to you that the Life Cycles stated are WITH Expensive Electrolyte changes included.
Changhong and the Electric Indian does Not need to operate a Lying dreamland.
They have a Lot of different products in over 100 Countries. Lot's of different battery chemistries as well.

So changing the Electrolyte at 7-10 years is a real joke if you even slightly abused the new Ni-Fe Cells.
The batteries were totally shot before that - even at 60% DOD each day.
Let along running them 85% dead every day like somebodies fool. Only because much of the manufacturer's
data had been kept from you or what was available went unnoticed.

A NEW Look at old Charging routine's may be needed for Longer electrolyte life and less problems in general.

Now more than ever the name of the game is to avoid Positive Element Contamination from The Very
Beginning. It's NOT just Carbonates that you have to worry about.

According to certified research notes from Thomas A. Edison the Ni-Fe Cells (in time) are fully capable of
Self Destruction - all by themselves. Iron Poisoning of the Positive Electrodes. (another post)

The Carbonates and OTHER Contaminates is nothing but window dressing to the badboys in comparison.
(Lord willing, to be continued.)

Bill Blake

BillBlake · July 2012

Re: Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

Ni-Fe is such a long, drawn out, intense (and for some people very interesting) subject that it's easy for me
(or others) to over simplify a point or two. Let's face it the 'Compare Nickel-Iron Batteries' post was plenty
long enough as it was.

Anyway there are a number of methods to bring the Ni-Fe Cells and / or the Ni-Fe Electrolyte Back from the Dead.
Taking the cells apart
and separating the positive elements from the negative elements was without a doubt the most effective method.

However that was not the only sweet method. The devils. :-)

The first Edison Ni-Fe Cell Reconditioning method may be applicable to Today's Changhong Ni-Fe Cells or it may not.

Either Changhong needs to step up to the plate, since they see what I say (for free) or someone that milks a buck off the
Ni-Fe Cells needs to get off a few dollars for testing to commence.

My job as an old hobbyist was to try to reverse the Ni-Fe Lies and the Ni-Fe nonsense. 'Drop the Dime'.

Not do it all.

We heard a lot from the various Ni-Fe sales gang HERE in the past. I have notified them that I'm exposing what upsets me.
As usual my invitation for the Ni-Fe Poster's that milk good dollars out of the Ni-Fe game to step forth and
'speak into the mike' still stands mightily.

Today's Thoughts: From another topic but very applicable.

Inadequate data to compare Ni-Fe Cells to other battery technologies.

Mr. Edison knew about a number of Ni-Fe electrolyte problems by 1904.
They came up with both the first Electrolyte Filtering process
and also the first (Bring the Ni-Fe Cells back from the Dead) Elements Clean-up Reconditioning method
in 1904.

More Filtration (Treatment) methods and more Ni-Fe Cell Reconditioning methods came along in future
years just before World War One for the US Navy Submarines and then in the early 1920's.

The entire Ni-Fe subject seems to have been subject to some kind of a selfish, twisted, weird
twilight zone where for no good reason that I can figure
all these facts (and many more) became lost knowledge just waiting
on the right old man to take the subject on as a mysterious hobby and a giant puzzle to stomp.

The Edison Nickel Iron Batteries as well as the Changhong Ni-Fe Batteries that
Beutilityfree and Iron Edison sell were without a doubt subjected to endless
Lies, myths, tales, planted stories, etc.

Never any worse than this misguided 'Run the Ni-Fe Cells 85% Dead' sales campaign of 2012
that is going to hurt some people real bad if they buy it.
Edison's Nickel Iron batteries never were just Nickel and Iron except for some experiments.

Edison liked his Mercury and had great success with 20% Mercury in the Negative Elements.

A Number of other Metals were Used and incorporated into the batteries including a lot of Cobalt
which is why there are a number of historians that talk about Edison running all over the place
looking for Cobalt mines.

It goes on and on and on. The bottom line is sound bite posts and just a veneer of knowledge about the
Ni-Fe Technology isn't going to cut it other than for a sales hustle. It took someone that was not milking
the badboy for a buck to look at it.

Until we find out what mixture of metals (or other additives) that Changhong and the Electric Indian
is using in modern Ni-Fe Cells and whether their polypropylene separators
and plastic cases can take the same heat (for 10 to 30 hours) that the Edison Cells could take -
we have no idea whether the Cells can be Reconditioned or not.

The 1904 reconditioning method does not require cutting the batteries open and brings them back to
close to new capacity while the Elements are still inside the battery cases.
Plus they can take an Occasional malfunction and Abuse without destruction.
What about these other technologies?

The Ni-Fe Charging and Discharging schemes also need to be looked at.
Some problems may be unnecessary.

Bill Blake

BillBlake · August 2012

Re: Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

A few points about Nickel Rechargeable Cells made by Changhong Batteries in China.
There are a couple of items also applicable to Lead Acid that grabbed me a little.
This advice seems to have been formulated before the 'Solar Blivet Charging'
Solar Sales campaign (supposedly) launched around Oct., 2010.

Many are now trying to squeeze the 8 hours worth of charge into a 4 pound bag - including China.
Big problems can develop. Ni-Fe battery dealers (Changhong resellers) suffer from a severe lack of education
which is the biggest problem of all. Too much vital information is being held back from buyers.

blivet definition: <snip>

/bliv'*t/ [allegedly from a World War II military term meaning "ten pounds of manure in a five-pound bag"]

1. An intractable problem.
2. A crucial piece of hardware that can't be fixed or replaced if it breaks.
3. A tool that has been hacked over by so many incompetent programmers that it has become an unmaintainable tissue of hacks.
4. An out-of-control but unkillable development effort.
5. An embarrassing bug that pops up during a customer demo.
6. In the subjargon of computer security specialists, a denial-of-service attack performed by hogging limited resources that have no access controls (for example, shared spool space on a multi-user system).

This term has other meanings in other technical cultures; among experimental physicists and hardware engineers of various kinds it seems to mean any random object of unknown purpose (similar to hackish use of frob). It has also been used to describe an amusing trick-the-eye drawing resembling a three-pronged fork that appears to depict a three-dimensional object until one realises that the
parts fit together in an impossible way.

http://search.yahoo.com/search;_ylt=AnV8FaYH.TroaC8yON_SuVmbvZx4?fr=yfp-t-701-s&toggle=1&cop=mss&ei=UTF-8&p=blivet%20definition

Tech. Support:

The following are the most frequently asked questions. However, if you have a question that does not appear on this list,
please contact us.

1. What is battery conversion efficiency, Equalizing charge and full charge

Conversion efficiency refers to the ration between continuous and stable power in the actual the power supply and nominal power .

Equalizing charge is a continuous recharging to ensure that each single cell is fully charged.

Full charge refers that all the available active substances in the battery change to the state of full charge.

2. What is charging efficiency and discharge efficiency?

Charging efficiency is ration that released power in the condition of discharge versus the power restored the initial charging state. Charging efficiency is affected by charging rate and environment temperature. During the charging, charging current must be within a certain range, the current too small or too large ,charging efficiency is low. Since the batteries exist self-discharge, batteries can’t be charged fully, and battery closer saturation, charging efficiency is lower.

Discharge efficiency is ration that released actual power in the certain condition of discharge to final voltage versus nominal capacity . Discharge efficiency is affected mainly by the discharge rate, environmental temperature, the resistance. Normally, higher discharge rate, the lower discharge efficiency. Temperature is lower, the discharge efficiency is lower.

3. The reason why battery energy conversion process causes of the loss, how much is scale of all aspects of the energy loss?

Internal resistance of the battery (including metal resistance, solution resistance, separator resistance), gas generation during electrolysis of water can cause loss of power.

The gases are generated during overcharging and over-discharging. When the battery is overcharged, water can be decomposed, battery anode generates oxygen , negative generates hydrogen .If the batteries are overcharged 1Ah, generally, the gas of 4.1 cm3 will be generated., the opposite situation during over-discharge.

The battery commonly uses the method of excess capacity of battery negative to prevent excess hydrogen. overcharge or over-discharge will damage the battery life, so in use process, avoid overcharge and over-discharge.

4. What current value of Equalizing charge? And what value of environmental temperature? If battery charging conditions can’t be guaranteed , what effect may cause to the battery?

Equalizing charge is a continuous recharging to ensure that each single cell is fully charged,. The current generally is about 0.2 ItA , the environmental temperature should be about 20 ?. If charging conditions can’t be guaranteed,
the battery charging state will be affected, such as:

if the charging current is higher, electrolysis of water is more vigorous, the battery can’t be charged fully.

Environmental temperature is exorbitant, the electrolyte is easy to be volatilized , it causes "dry" battery, and damages the battery life.

5. What method is for full charge? What conditions to meet (voltage, current, time, temperature)?

Commonly constant current charge and constant voltage charge are used for full charge at 20? ??

?1?Constant current charge : charge the battery at current of 0.2 ItA for 8 hours.

?2?If the battery is not used, the battery capacity should be supplemented with low current of 0.1 ItA -0.05 ItA for long time.

?3?According to the use condition of the battery, rated voltage can be different:

a) if the battery is for standby, and occasional discharge? two sections can be adopted to charge the battery
(first stage: 145-1.70 V/single cell,
the second stage: 1.40 V/single cell)
or one section can be adopted to charge the battery(143-1.50 V/single cell) ,

b) If the battery is used frequently, the battery is charged at the voltage of 1.5-1.60 V/single cell.

6. Why does the battery make full charge?

The purpose of full charge is to let all the available active substances be fully utilized, and ensure the capacity of the battery.

There are a couple of real Pearls mixed in there if you read it a couple of times and allow for the language difference.
They build quite a number of different types of batteries and are part of a multi-billion dollar operation.
Most of the time I feel that they try to be straight but they seem to allow problems with sub-standard sales distribution
in North America. The market may not have given them a lot of quality choices - so far.

Bill Blake

niel · August 2012

Re: Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

again, lots of good info from you bill.

NIFEinME · February 2013

Re: Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

BillBlake wrote: »

The 1904 reconditioning method does not require cutting the batteries open and brings them back to
close to new capacity while the Elements are still inside the battery cases.

Bill Blake

Hi Bill, I hope you are still patrolling this board.

I am working no bringing back a string of C-6 Edison cells, manufactured in the early 50's.

Could you provide more detail on the "1904 reconditioned method"?

Thanks

niel · February 2013

Re: Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

bill has not been by since dec 26, 2012. if you are interested i can contact him via his last reported email address that you are wanting to hear from him.

NIFEinME · February 2013

Re: Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

niel wrote: »

bill has not been by since dec 26, 2012. if you are interested i can contact him via his last reported email address that you are wanting to hear from him.

Thank you very much, I would really appreciate that!

Thanks again.

Randall · February 2013

Re: Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

Hi NIFE user, I also have a some C-6 Edison cells. The method(s) for reconditioning Edison cells can be found in Edison's own patents. Don't ask someone that does not actuality own any Edison cells or someone that does not post any real literature on Edison cells. I have been all over the web for the last couple of years studying up on these batteries and have found very little published data. I do have a Edison battery manual that does have all of specs on your C-6 cells. I have not been able to find this manual on the web but was able to purchase an original manual from ebay. Feel good about your self now that you own some Edison cells, you know more than 99% percent of these people in these forums. There is just to much BS in these forums to carry out any good discussion. No disrespect to any users here. Just my two cents, feel free to contact me.

Cariboocoot · February 2013

Re: Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

Welcome to the forum Randall.

Randall wrote: »

Feel good about your self now that you own some Edison cells, you know more than 99% percent of these people in these forums. There is just to much BS in these forums to carry out any good discussion. No disrespect to any users here. Just my two cents, feel free to contact me.

We're going to choose to believe you mean "know more than most people on the various forums about NiFe batteries" rather than knowledge in general or on this specific forum. Otherwise despite the disclaimer in your post it would be disrespectful of users.

Randall · February 2013

Re: Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

Sorry I miss spoke, your assumption is correct. My intent was meant to say "NIFEinME" knows more about Edison cells and not about Chinese cells or on any other topic. But I'll go one step further and change my statement of "know" or knowledge to experience. Also would like to add that this is a great forum and have been visiting for here for some time. It's just the topic on NIFE batteries that I was referring to the BS. I joined this forum with the intent to make contact with others that are using and reconditioning Edison cells like my self.

BB. · February 2013

Re: Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

Randall,

If you would like to start your own thread and supply details/summary/links to NiFE battery maintenance and experiences... Please do.

As the original poster in a thread, you set/manage the subject matter and direction. We (the moderators) will help split off posts that should have their own threads if they start to stray too far.

-Bill

BB. · February 2013

Re: Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

Here is some historical information from http://opensourceecology.org/wiki/Edison_Battery

Marketing cut-away of an Edison battery

Edison's Patent for Reversible Galvanic Battery - 1901 (678722)

Edison's Patent for Alkaline Battery - 1906 (827297)

Edison's Patent for Storage-Battery Electrode-Plate - 1906 (831269)

Edison's Patent for Insulated Battery Box - 1918 (1266780)

The Edison Alkaline Storage Battery (1916)

The Storage Battery: A practical treatise on the construction, theory, and use of secondary batteries ( Treadwell, 1898 )

-Bill

mike95490 · February 2013

Re: Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

BB. wrote: »

Here is some historical information from http://opensourceecology.org/wiki/Edison_Battery
-Bill

""Like"" Thanks.

Vic · February 2013

Re: Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

Hi mike9 ...,

Believe that you ARE using NiFe batteries. If so, how are they/you doing? Anytning to report?
Thanks, Vic

mike95490 · February 2013

Re: Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

Yep, got a large bank here, been running just over a year, first 9 months they were idling along with no loads except 1 fridge. Now house is built ( only generator needed was for cloudy days, and a 12KW for floor sanding ) So, I'm learning that even a 800ah bank, really does not like heavy loads, the voltage will sag, but after a couple hours of light load, they recover. I've been running genset AM's this last month, to boost the batteries for the wifes morning toast, and letting the sun top them off. Now days are getting longer, and less AM clouds, so no generator last 2 days, still have toast and microwave.

I do suspect carbonation is happening and have the test kit, but not the time to devote to it, since we just planted 40 blueberries, and have another 20 plants that came in over the weekend.

Mine are from China, and way too early to say I'm happy with them, if they are still going good in 15 years, that's when I'll be happy. Not sure I will like doing the electrolyte changes, since they don't have a "drain", and I'll be needing to mix a fresh 100 gallons of electrolyte and dispose of 100 gal used.

NIFEinME · February 2013

Re: Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

Hello Randall, and everyone who has chimed in.

Randall, I am curious how far you have gotten with your restoration.

My own progress has gotten to the point of cleaned cells and a fresh batch of electrolyte to 1.25 SG for a 10 cell array. I have enough cells to put together a larger string, but only have a charger capable of delivering 18V at about 20A. Have given the string several charge and discharges, but am not getting near the nominal 337.5 Ah. My best is about 60 Ah worth of discharge to 100% DoD as measured by a Trimetric AH meter.

I followed the cleaning method I found in Edison's 16 page "General Information and Instructions for the Operation and Care of the Edison Alkaline Storage Battery -- Bulletin 850 X". On page 9 the instructions for Solution Renewal read: ""When ready to refill, first discharge the battery to zero voltage. Pour out about half of the old solution, shake the balance vigorously and empty. Do not rinse with water, use only the old solution."

Randall, are these the the same instructions as in your literature?

As far as following these instructions, I found that it was necessary to shake vigorously many times until the flushed liquid would run clear. My understanding is that the carbonates contaminating the solution are a result of atmospheric CO2 interacting with the solution during the off-gassing caused by charging. I found it necessary to use distilled water to perform the majority of the flushes, as the old solution poured almost black, and would need to sit overnight to settle before reusing to shake and flush. Since the same manual states several times not to let the cells stand empty, and to fill either with solution or distilled water -- I decided it would be acceptable to flush with distilled water.

For anyone else working on flushing cells, I've found that clamping an individual cell onto a pivot provides much easier way to slosh the cells clean rather than shaking them by hand.

My open questions to Randall and any other forum users who have experience with Edison cells are:

1. Are there other cleaning methods that have provided success, especially for heavily carbonated solutions/cells?

2. Is my assumption that my charger does not provide enough amperage to adequately charge the cells reasonable? Though I compensated for available amps by extending the boost charge (so that watt-hours equaled what a nominal boost charge should be in watt-hours), perhaps charging at ~20A for cells that specify charging at 67.5 Amps just doesn't provide enough current to overcome the internal resistance.

3 What is a reasonable expectation for best outcome of rejuvenation? If the cells were orginally rated for 337.5 Ah, could I expect 50% of that after reconditioning, better?

Thanks and looking forward to any responses.

westbranch · February 2013

Re: Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

I have some wet NiCd's... from your post I ask myself.... are these Edison's using a Lye solution for electrolyte? (carbonates was the clue)

NIFEinME · February 2013

Re: Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

The solution is KOH and distilled water mixed to a specific gravity of about 1.25.

Potassium Hydroxide is also known as caustic potash, and like NiCads is an alkaline solution.

westbranch · February 2013

Re: Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

OK, I thought so.. KOH.... the manual I have for my NiCd cells recommends to rinse with distilled, deionized water until all the deposits are removed, then refill.

hth

mike95490 · February 2013

Re: Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

with NiFe, you do not want to use straight water (distilled). The iron will rust without the KoH solution. Once you get rusty iron, I have no idea how to clean that. So rinsing should be done with native KoH electrolyte.

NIFEinME · February 2013

Re: Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

Hi Mike, I agree.

In practice I found that there was simply not enough electrolyte available to slosh clean the cells until the dump runs clear. I could have mixed a new batch of electrolyte to use to rinse but given the number of cells am cleaning that is really not practical. My plan for the next big rinse out (30+ cells) is to stage the cells with a barrel of waste electrolyte, a barrel of rinse water/light electrolyte solution, and a barrel of fresh full strength electrolyte. I will dump the waste, rinse with the water/light solution, and refill with the fresh on a production line.

By the way, I sawall'd open a couple of damaged cells I had and inspected the plates, spacers and cannister. I found that despite sitting dry and/or with just water the none of the plates I inspected showed any sign of rust, though all were well coated with a carbonate build up. I also found very significant carbonate deposits in the bottom of the cannisters, enough that it is feasible they could extend all the the way from the bottom to touch one or more of the plates. It is my speculation that when this happens the cell is "shorted". In the scenario taking a voltage reading across the terminals yields 0.00V (or very close to it), but taking a reading from one of the terminals to the canister it self often reads a nominal volatage in the (+/-) 0.5V range.

I experimented with cleaning solutions for these scrap cells/plates and found that standing them in vinegar will loosen the carbonate deposits enough to fall apart be cleaned off without direct pressure. I have not tried this with any intact cells, but if I find that there is a cell which will not take a charge and show a 0.0V after a flushing and electrolyte change I may be temped to try it.

Thanks for your response Mike, and in any case I do not let intact cells sit empty or with distilled water for any length of time, just for duration it takes to slosh them out.

I anyone has any better practices, I'm all ears.

Thanks.

westbranch · February 2013

Re: Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

For the NiCd's the manual distinctly states not to get any acids anywhere near the cells. Base neutralization... So it might be a good experiment to check if there is any residual vinegar left on the plates that lowers the SG of the KOH solution (electrolyte) when recharging for use. I like the idea though of dissolving the carbonates.

NIFEinME · February 2013

Re: Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

Yep, that was the thought WestBranch.

I would still love to hear any feed back on my second question which I'm reposting below.

Thanks.

NIFEinME wrote: »

2. Is my assumption that my charger does not provide enough amperage to adequately charge the cells reasonable? Though I compensated for available amps by extending the boost charge (so that watt-hours equaled what a nominal boost charge should be in watt-hours), perhaps charging at ~20A for cells that specify charging at 67.5 Amps just doesn't provide enough current to overcome the internal resistance.

inetdog · February 2013

Re: Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

NIFEinME wrote: »

2. Is my assumption that my charger does not provide enough amperage to adequately charge the cells reasonable? Though I compensated for available amps by extending the boost charge (so that watt-hours equaled what a nominal boost charge should be in watt-hours), perhaps charging at ~20A for cells that specify charging at 67.5 Amps just doesn't provide enough current to overcome the internal resistance.

It is not current that overcomes internal resistance, it is voltage that overcomes the resistance to produce higher current.
As long as the current you supply is greater than the self-discharge current, it will eventually result in full charge as long as the voltage is allowed to rise high enough as the SOC increases.

But in some cases the difference in current density (amps per cm² of plate) will have an effect on the way the chemical reaction on the plate surface forms small or large crystals, etc. That could affect the long term capacity of the cell and could lead to a decrease in active surface area causing a higher internal resistance on discharge after a very slow charge. But any such changes should be reversible by a deep discharge followed by charging at the recommended current. This is purely a hypothetical discussion, without any claim that it applies specifically to NiFe batteries.

Iron Bran · February 2013

Re: Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

Here are some actual Nickel Iron battery project photos from Iron Edison. This is a 24 Volt 400 Amp hour battery with an Apollo Pre-Wired Panel. The PWP includes the solar charge controller, inverter, and DC disconnect.

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Iron Bran · February 2013

Re: Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

Here is a very recent project. Check out this 1000 Amp hour 48 Volt battery installed by Iron Edison in Colorado. This one battery can hold up to 48 kWh of stored energy. The battery is complimented by 15 kW of solar and dual SMA Sunny Island inverters. All told, there are 7 inverters in this AC coupled system.

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NIFEinME · February 2013

Re: Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

inetdog wrote: »

It is not current that overcomes internal resistance, it is voltage that overcomes the resistance to produce higher current.
As long as the current you supply is greater than the self-discharge current, it will eventually result in full charge as long as the voltage is allowed to rise high enough as the SOC increases.

But in some cases the difference in current density (amps per cm² of plate) will have an effect on the way the chemical reaction on the plate surface forms small or large crystals, etc. That could affect the long term capacity of the cell and could lead to a decrease in active surface area causing a higher internal resistance on discharge after a very slow charge. But any such changes should be reversible by a deep discharge followed by charging at the recommended current. This is purely a hypothetical discussion, without any claim that it applies specifically to NiFe batteries.

Hi inetdog, thanks for the response.

In my case, the charger that I am using is limited in both its voltage and current output. Neither is high enough for the nominal values that the array wants. The Edison manual states that this array should get 18.5 volts at 67.5 amps for 7 hours. My charger can do about 17 volts at about 20 amps at best over a period of time. As it is designed for tending auto LA batteries, it has no intelligence to give bulk, absorb or float charges. . .I cannot specify either current of voltage, it gives what it gives. The only control I have is to give it more than the specified 7 hours.

As stated, I've boost/equalized charged this at times for more than 24 hours (the the watt-hour calculation suggests this duration). What is still an open question in my mind is the following: Given that I have neither the specified amps or volts to charge with, is the additional time sufficient? The voltage does not increase as the SOC increases, so I do not know if the voltage is sufficient to overcome the resistance.

Any insight would be greatly appreciated.

I am also very open to suggestions for specific chargers that would work for me to prove/disprove the viability of these cells. Thanks to Iron Bran for the pics. . .is there a specific inverter/charger that you recommend that could provide the 67.5 amps at 18.5 volts?

Thanks.

inetdog · February 2013

Re: Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

NIFEinME wrote: »

Hi inetdog, thanks for the response.

In my case, the charger that I am using is limited in both its voltage and current output. Neither is high enough for the nominal values that the array wants. The Edison manual states that this array should get 18.5 volts at 67.5 amps for 7 hours. My charger can do about 17 volts at about 20 amps at best over a period of time. The voltage does not increase as the SOC increases, so I do not know if the voltage is sufficient to overcome the resistance.
Any insight would be greatly appreciated.

You have the right idea, but are using the wrong words to describe it. As the SOC of the battery increases, the open circuit voltage of the battery also increases. If the open circuit voltage of a fully charged battery is, for example, 18.0 volts, then no amount of charging at 17 volts can get the battery past the SOC for which the open circuit voltage is 17 volts. You are not just trying to overcome the resistance of the battery, you are also trying to overcome the voltage of the battery itself.
Now the value of 18.5 volts at 67.5 amps probably allows for some resistance in the battery to the current flow of 67.5 amps, so that does not by itself mean that the open circuit voltage of a fully charged battery would be 18.5 volts. But if your charger cannot reach and go above the Float voltage specified for the bank, you will never properly charge it.

On the other hand, if the charger is actually delivering 20 amps to the bank continuously, regardless of the voltage, it is definitely still charging it.

Looking back I see that you are working with a 10 cell bank for which the nominal full charge voltage is about 16.5 volts. The specification of 18.5V and 67.5A is, as you mentioned, a forming/recovery charge regime. To the extent that the voltage itself does not play a critical part in the process, you should able to leave the 20 amp charger connected for a little over three times as long to get the same results.
But if you leave the charger running for 21 hours, then repeat the discharge/recharge cycle with no increase in cell capacity, you are probably not going to get any further improvement regardless of what you do short of disassembling the cells.
One critical thing to watch for is whether the cell capacities are staying closely matched. If they are not and there is only one cell which is much worse than the rest, then perhaps you may be better off leaving out one cell to produce a 9 cell bank and adjusting the voltages down accordingly.

NIFEinME · February 2013

Re: Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

Hi inetdog, thank you very much for your detailed response. This is the kind of feedback I was hoping for and is extremely helpful. Thanks again.

A few follow up questions/observations, if you don't mind:

1. Closely matching the cells: how would to determine this? Is it sufficient to disconnect the array and take each cells voltage independently, or should I discharge each cell independently to ascertain this? Perhaps some other method?

2. For my forming/recover/boost charge at ~18.5V and ~20A, I have noticed a slight increase in capacity over a series of charge/discharge cycles. What prompted my question was feedback from someone knowledgeable about Edison battery recovery stating that there is not a enough amperage available to fully restore cell at ~20A. Your explanation of the relationship of open circuit voltage and charging amperage is enlightening. I wonder if you have any thoughts on his opinion that ~20A may just not be enough to recover more than a fraction of the nominal AH capacity.

3. Some of the original Edison literature states that periodic "overcharges" are helpful in recovering cells. I have seen reference to 12 hour and even longer charges at the full charging rate (in this case 18.5V/67.5A) after changing electrolyte and/or restoring a cell left standing for some time. That implies to me that the power supplied for longer than normal needs to be of the full specified voltage and amperage for an expected recovery. Do you have any thoughts on this vis-a-vis using the less powerful ~20A charger for an even longer period of time (~2 days)?

Thanks again, I am extremely appreciative of your thoughts.

inetdog · February 2013

Re: Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

NIFEinME wrote: »

1. Closely matching the cells: how would to determine this? Is it sufficient to disconnect the array and take each cells voltage independently, or should I discharge each cell independently to ascertain this? Perhaps some other method?

2. For my forming/recover/boost charge at ~18.5V and ~20A, I have noticed a slight increase in capacity over a series of charge/discharge cycles. What prompted my question was feedback from someone knowledgeable about Edison battery recovery stating that there is not a enough amperage available to fully restore cell at ~20A. Your explanation of the relationship of open circuit voltage and charging amperage is enlightening. I wonder if you have any thoughts on his opinion that ~20A may just not be enough to recover more than a fraction of the nominal AH capacity.

3. Some of the original Edison literature states that periodic "overcharges" are helpful in recovering cells. I have seen reference to 12 hour and even longer charges at the full charging rate (in this case 18.5V/67.5A) after changing electrolyte and/or restoring a cell left standing for some time. That implies to me that the power supplied for longer than normal needs to be of the full specified voltage and amperage for an expected recovery. Do you have any thoughts on this vis-a-vis using the less powerful ~20A charger for an even longer period of time (~2 days)?

1. One thing you can do is discharge the whole series string to some nominal cutoff point (10 volts for a 10 cell string?) and then measure the individual cell voltages. A cell whose voltage is well below 1.0 volts will be one which has a low capacity compared to the rest of the bank and will be limiting the amount of power available. If any cell goes down to 0 volts or reverses its polarity, you should not have discharged the bank that far! By actually discharging each cell individually with a load connected just across that cell you will be able to get some idea of the total capacity of each cell. But you probably do not have the equipment needed to do that and record the current versus time.

2.
3.
I do not have enough experience or knowledge to give you authoritative recommendations on those points. In some other chemistries it is true that a continued charge at a low current will not have the same effect as a shorter charge at a higher current and voltage. In particular a high current charge will be more likely to produce a small-crystalled, high area surface, active material than a slower charge would. And more likely to have a uniform effect across the entire area of the plates.

westbranch · February 2013

Re: Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

The load test I use for my NiCd's is @ full charge:

apply (C x .2) load for 5 hrs documenting V at Hr 1, 2, 3, 4, 4.5 and 5 for each cell.

between 4 and 4.5 weakest cells will show (sometimes before then) and these are the suspect ones.
Re charge and do another load test. If cell does not show some improvement change electrolyte.

Same procedure should work for Ni Fe.

Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

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