Nickel Iron vs. Lead Acid - Off Grid battery debate

[john p]

Here we have to conflicting opinions/reasons for using different batteries
Sunking does not like nickel iron mosly because ineffecient and expensive
Isoutar likes them for longevity and a possible vested interest
I have assembled small solar systems using Lithium Ion Phosphate because zero maintinance easy to charge with a PWM charge controller that has adjustable charge voltages, but high price. Why? for house security lighting where peace of mind not cost is the overriding factor.

There is no one size fits all, and sometimes purchase price is NOT the deciding factor,

Its been pointed out in other threads that lead acid batteries are fully recyclable. true to a point.. but not true if you have no place to send them and or no means to economically get them to a recycle place. so the acid gets just poured out on the ground or in a waterway the case discarded and the lead gets save ??? to be played with by children who beat it with a stone into different shapes.. free lead poisioning for all.
2/3 rds of the world live in poverty and dont have access to things (like safe recycling)some of the people on here take for granted. I be willing to bet most of the posters on these sites have not left the country they were born in and seen the real problems in so many other countries.

[isoutar]

Lithium Iron Phosphate ... another great long life battery like NiFe.

I have indeed encounted trouble with SunKing and friends on other sites. They are not willing to honour the fact that we all have our reasons for selecting the technology that we like. There is no need for a uniform opinion on the subject. Most of us here have vested interests somewhere in the field of RE.

Some people are driven solely by price and others have technical reasons for making choices that are not based only on price. I am one of the latter. There is no reason to insist on a fixed "right or wrong" answer. Everyone can be riight! We just have differing reasons for our selections.

I have abandoned having an interest in Nickel Iron cell sales. I prefer to make my money on system design services. If you have ever contacted me concerning Nickel Iron you will find that I simply let everyone order directly from Changhong in China. I decided not to sell them myself because there was a need for the technology to be as cheap as possible. My website will reflect this upon the next edit. However I am making money on the design of such systems for scientific and humanitarian applications that require a long lifespan.

One such application I am currently working on is a remote solar powered astronomical observatory power where batteries need to be delivered by helicopter to a mountaintop. They are very fussy about the lifespan of the battery since each delivery costs at least 10 times as much as the batteries are worth. This is a very typical application where the battery cost is simply not selection criteria. The best economic choice in that case is either Nickel Iron or flooded Nickel Cadmium. Cadmium is the technically best choice but everyone is moving away from Cadmium, especially in Europe due to toxicity.

The other battery I do love is the one mentioned in the quoted comments beislow. Lithium Iron Phosphate or the A123Systems battery. It has a remarkable lifespan but does have its issues if the controller fails. However our group of enthusiasts here in Victoria who build solar electric boats are experimenting with both Nickel Iron and Lithium Iron Phosphate. The lithium gives a much better power density and is good for speedboats. The nickel iron is fine for cruising in a displacement hull. The same displacement hull boat has been fitted with lead acid or nickel iron and the power density is so similar that there is no difference in the perfromance of that boat. The speed boat however must have the lithium.

For the high power density applications the Lithium Iron Phosphate batteries (patented by A123Systems) is superb with a long life matching the nickel iron cells endurance combined with high power density. It needs very careful charge control and cooling.

The Vancouver Electric Vehicle Association website is worth studying to learn more about battery technology. I have never been to their place in Vancouver but they do maintain a museum of old electric cars and have a wealth of information about batteries.

Here is the Vancouver Electric Vehicle Assocation website ... a great battery resource ...

http://www.veva.bc.ca/home/index.php

Ian Soutar
Vancovuer Island
Canada.

Here we have to conflicting opinions/reasons for using different batteries
Sunking does not like nickel iron mosly because ineffecient and expensive
Isoutar likes them for longevity and a possible vested interest
I have assembled small solar systems using Lithium Ion Phosphate because zero maintinance easy to charge with a PWM charge controller that has adjustable charge voltages, but high price. Why? for house security lighting where peace of mind not cost is the overriding factor.

There is no one size fits all, and sometimes purchase price is NOT the deciding factor,

Its been pointed out in other threads that lead acid batteries are fully recyclable. true to a point.. but not true if you have no place to send them and or no means to economically get them to a recycle place. so the acid gets just poured out on the ground or in a waterway the case discarded and the lead gets save ??? to be played with by children who beat it with a stone into different shapes.. free lead poisioning for all.
2/3 rds of the world live in poverty and dont have access to things (like safe recycling)some of the people on here take for granted. I be willing to bet most of the posters on these sites have not left the country they were born in and seen the real problems in so many other countries.

[Mike90250]

Mod note.

I'm following this fairly closely, and am enjoying the debate and exchange of ideas/thoughts. I am due for new batteries this summer, and am considering all options that don't require me to mortgage my soul. Even looked at used Prius packs

Looking at 900Ah lead acid, or 600Ah Nife, but wondering if the NiFe cells are shipped dry, and if so, how rust is prevented and how to get 60 gallons distilled water to mix electrolyte for filling.

Between the top end HUP and Hawker PB, and the NiFe, the prices are not as different as Trojan Pb & NiFe

[Mike90250]

Mike where are you coming up with those numbers? Current price for FLA is around $0.14/wh, and NiFe around $4 to $6/wh.

Personally if i had the money to burn, I would looking at LFP from A123 Systems for around $1/wh and they run circles around LiFe

a) don't need as many watts to avoid 50% discharge

b) if the charger burps or farts, the cells are toast, balancers cost as much as the batteries, from what I can tell.

c) NiFe, can use same charger, just a tweak to the setpoints.

[Sunking]

The other battery I do love is the one mentioned in the quoted comments beislow. Lithium Iron Phosphate or the A123Systems battery. It has a remarkable lifespan but does have its issues if the controller fails. The lithium gives a much better power density

For the high power density applications the Lithium Iron Phosphate batteries (patented by A123Systems) is superb with a long life matching the nickel iron cells endurance combined with high power density. It needs very careful charge control and cooling.

Ian that has been my point the whole time. There are better less expensive options than NiFe, not too mention LFP voltage curves work very well with standard 12, 24, 36, and 48 volt equipment.

Granted the charge controller requires some special care, but they are not as sensitive as made out to be especially using the lower charge rates of solar panels. In fact the if using just a C/20 to C/5 charge rate the algorithm is extremely simple just a plain ole constant current until 4.2 vpc is reached them terminate. Much simpler than FLA chemistry.

[john p]

Isotour to be fair Sunking has given only facts in each and every post on the subject of Nickel iron batteries.
But sometimes just facts are not enough to tell you what is the best item to use for your situation

Its a fact a tomato is a fruit but its wisdom that says its not good to put it in the fruit salad.

In small below 1000 wpanels and below a 1000 w inverter Lithium Ion Phospate batteries are not over the top expensive and as I have proved now on systems that I assembled almost 4 yrs ago can be charged easily with a std adjustable charge voltage PWM controller.

In Australia the cost of lead acid batteries of good quality that can be deep cycled are about 40 to 70% higher than in USA. this can totally alter the cost benefits over other batteries.

[john p]

For anyone that is interested this is a reprint of a post from last year. about how to set up a small but useful solar setup using lithium ion phosphate batteries..

IF anyone is interested this is how I have set up 3 x100ahr LiFePo4 batteries for charging by solar and for use with MSW inverter..
Im not claiming this is the correct way or even the best way to do it,, But dont tell me it wont work as all 3 systems been in use over 3 years now almost 4 years with NO PROBLEMS
Charger a 30a PWM 12v charger set to output 14.8v with no equalization..
Battery cell over charging 1x 3.9V 1watt zenner diode and 1x10ohm resistor across each cell
One low voltage sensor set to disconnect the inverter and anything else connected to the battery pack at 10v
Facts as found out the expensive way by me are if you discharge a cell below about 2.2 v it will be destroyed even if done just one time only.
If you over charge above about 4.4v they have a very short life.
If you look at charts from the manufacturesr you find there is little power above 3.8v and it stays fairly constant until about 2.5v then hits a brick wall.
So use between those 2 voltages and all is well with the world.
I have never found a MSW inverter that has problems with operating between 15.5v and 10.5 v and that is the usual specs given by most MSW invereter manufacturers..

[Iron Bran]

Edison restoration photos

UPDATE: Working on bringing some very old Edison cells back to life. One cell is holding a charge, and I just opened up three of the perforated metal cases.

https://picasaweb.google.com/110321674492695329085/InsideTheNiFeCell

Hi everyone,

I am interested in learning if you have any experience with non-traditional battery systems?

Is anyone using ni-cad or nickel iron? I am looking into Nickel Iron (ni-fe), anyone currently using these?

Thanks!

[Iron Bran]

More nickel iron photos

Enjoy...

[isoutar]

Yes ... there are people using NiFe cells for RE and are pleased with them.

Yes, my wife and I are living with Solar and Nickel Iron cells for all our lighting and computers.

Very pleased with them ... I have abused them like crazy ... discharging them completely for several weeks around christmas time last year. Their performance improved remarkably just as Edison had suggested. I think you can kill them ... but it might take a sledge hammer to do it.

I was going to sell them but I got into a geiger counter project and I decided I was not into being a battery salesman. In addition a service club is hiring my company to do a bunch of solar powered lighting systems for African schools and hospitals. These will all be NiFe systems. The service club had built solar schools over the last decade but each school ended up having a large graveyard of lead acid batteries ... they were thinking of abandoning the solar approach because of the lead batteries! A woman from Africa I met last week was speaking of the mess that lead batteries have created in her small town.

I also recommended nickel metal hydride for smaller installations in the home where the flooded stationary nife battery system was inappropriate. Nickel Metal Hydride is worth looking at ... the D size cells put out 10 amps at 1.2 volts. Another friend runs his car (gasoline car) with a battery pack he made up using D cells. The battery pack is about 1/3 the size of the original lead acid battery he was using. This kind of pack is great for small huts and cabins to provide for LED lighting.

Nickel Iron cells sure are worry free ... it is great to be able to overcharge them for weeks too. Last summer I ran them at the peak of summer just connected to my solar panels ... a drastic overcharge. I kept adding water each week because the overcharge uses water. But again their performance improved slightly ... but not as much as they improved after a few deep discharges.

I would not recommend running with no charge controller unless you like buying distilled water!

Ian Soutar

http://www.microsec.net

UPDATE: Working on bringing some very old Edison cells back to life. One cell is holding a charge, and I just opened up three of the perforated metal cases.

https://picasaweb.google.com/110321674492695329085/InsideTheNiFeCell

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[ATTACH=CONFIG]892[/ATTACH]

[Iron Bran]

Charge / Discharge Chart

Real data...

[isoutar]

Operating NiFe without a charge controller at all.

I initially ran my bank of NiFe cells without a charge controller just to verify that this kind of abuse will not affect the cells. I needed to add water after a week since the batteries were charged by 10 or 11 in the morning and just bubbled hydrogen for the rest of the day. No problems though ... overcharging has no negative effect at all on Nickel Iron Battery systems ... you just have to keep on top of the water.

But when I switched to an Outback MX60 controller and set the charge voltages, then I only needed to fill the batteries a bit in spring and fall.

I would recommend a charge controller but it is not essential with Nickel Iron as long as you are willing to fill the batteries regularly.

Ian Soutar

I have a small solar system that powers my garage. The solar panels add up to 90 watts. This has been in use now for ~ 5 years to power the lights, televison, radio and small power tools. The batteries I have been using are whatever is lying around, primarily glassmat alarm batteries and Nicads. I was about to buy a set of golf cart deep cycle lead acid batteries then remembered I had a bunch of Edison Nickel Iron cells on a shelf hidden by years of accumulation. I bought these in the late 70's from different sources and never used them. The electrolyte had long dried out to the point is was not visible through the fill caps. The newest set was manufactured in 1961, the oldest before 1928. After much research, I figured out the formula for the electrolyte and replaced it. This was followed by cycle testing with a motor/generator set and load resistors. In the end, the set made before 1928 is still at 65% of new rated capacity. The set made in 1961 is at 70-75% of new capacity. I have been using the newer set for a year now and am thrilled with the performance. I know they are expensive but seem to be a good fit for solar systems. Unlike other batteries, they really are nearly indestructible. I don't even have a charge controller hooked to them. I will get one at some point but just add water ever 3-4 months for now. The only difference to be considered with these is the need for a different charge controller. The fully charged voltage of a nickel iron set produces 14-15 volts and will trip off inverters designed for lead acid. There are inverters available with adjustable set points. For now, when working in the garage, I momentarily remove a couple of cells from the circuit to get the inverter started, then apply a load. Works for now !

[Iron Bran]

How did you identify the year??

Hi,

I have some old ni-fe batteries and need to find what year they are from.

Model: A6H
Serials:
2113AD
2146AD
2145AD
2156AD

I have a small solar system that powers my garage. The solar panels add up to 90 watts. This has been in use now for ~ 5 years to power the lights, televison, radio and small power tools. The batteries I have been using are whatever is lying around, primarily glassmat alarm batteries and Nicads. I was about to buy a set of golf cart deep cycle lead acid batteries then remembered I had a bunch of Edison Nickel Iron cells on a shelf hidden by years of accumulation. I bought these in the late 70's from different sources and never used them. The electrolyte had long dried out to the point is was not visible through the fill caps. The newest set was manufactured in 1961, the oldest before 1928. After much research, I figured out the formula for the electrolyte and replaced it. This was followed by cycle testing with a motor/generator set and load resistors. In the end, the set made before 1928 is still at 65% of new rated capacity. The set made in 1961 is at 70-75% of new capacity. I have been using the newer set for a year now and am thrilled with the performance. I know they are expensive but seem to be a good fit for solar systems. Unlike other batteries, they really are nearly indestructible. I don't even have a charge controller hooked to them. I will get one at some point but just add water ever 3-4 months for now. The only difference to be considered with these is the need for a different charge controller. The fully charged voltage of a nickel iron set produces 14-15 volts and will trip off inverters designed for lead acid. There are inverters available with adjustable set points. For now, when working in the garage, I momentarily remove a couple of cells from the circuit to get the inverter started, then apply a load. Works for now !

[isoutar]

Lots of Experimentation with Nickel Iron Cells underway in Canada.

Iron Bran

Thanks for your discussions ... lots of real experience in the forum here with Nickel Iron cells now. A year ago it was mostly theoretical talk.

In Canada there are a number of large experiments underway this year using Nickel Iron cells. The largest installation will be in Manitoba where a 3000 ah system at 48 volts is going in. There is another system I know of in Northern Manitoba ... one that needs to operate at negative 40 degrees C in the winter. The owner is installing them outside and under his cottage specifically to see how well they work at -40 C or lower.

He had previously used lead acid banks but several were destroyed when his charge controller failed mid winter, the cells discharged, froze and were ruined.

I am not sure where the rumour came out that NiFe cells do not work in cold temperatures. It is one of their strong points.

A noteable old installation ... the main Toronto library has a bank of NiFe that they are still using to back up some of their computers. The power backup system was installed in the late 1960s and is still in use.

Canada is only just beginning to use NiFe cells again in large government funded projects and in some smaller privately owned energy systems.

Ian

Hi everyone,

I am interested in learning if you have any experience with non-traditional battery systems?

Is anyone using ni-cad or nickel iron? I am looking into Nickel Iron (ni-fe), anyone currently using these?

Thanks!

[isoutar]

Multiple charge voltages for nickel iron depending on conditions.

This is an interesting possibility ... multiple charge voltages for NiFe depending on season.

In the winter I charge to a full charge. That is because the sun might only be out for 2 hours and I want to pack the most energy into it.

In the spring and fall I change to midway between a full charge and a float charge.
In the summer I switch to just a float charge. These changes are done to prevent the need to water the batteries as often.

The controller is programmed with the new values at each season change. Since I design electronic products for a living, our company is designing an ideal nickel iron battery charger that takes advantage of the seasonal charge voltages.

I have never seen another battery design where you can simply choose the charge voltage that is most convenient. They cannot be destroyed even if you make a drastic error in this voltage.

Hey,

I am very interested on your thoughts on different efficiencies at different charge levels.

Here is a detailed writeup I found on charging, and I would like to hear what you think. Especially the 2nd paragraph. Granted, this is for NiCd but I just want to point out that efficiency is not exactly constant. Anyways amigo, check this out...

To obtain a sufficient voltage drop, the charge rate must be 0.5C and higher. Lower than 0.5C charge rates produce a very shallow voltage decrease that is often difficult to measure, especially if the cells are slightly mismatched. In a battery pack that has mismatched cells, each cell reaches the full charge at a different time and the curve gets distorted. Failing to achieve a sufficient negative slope allows the fast-charge to continue, causing excessive heat buildup due to overcharge. Chargers using the NDV must include other charge-termination methods to provide safe charging under all conditions. Most chargers also observe the battery temperature.

The charge efficiency factor of a standard NiCd is better on fast charge than slow charge. At a 1C charge rate, the typical charge efficiency is 1.1 or 91 percent. On an overnight slow charge (0.1C), the efficiency drops to 1.4 or 71 percent.

At a rate of 1C, the charge time of a NiCd is slightly longer than 60 minutes (66 minutes at an assumed charge efficiency of 1.1). The charge time on a battery that is partially discharged or cannot hold full capacity due to memory or other degradation is shorter accordingly. At a 0.1C charge rate, the charge time of an empty NiCd is about 14 hours, which relates to the charge efficiency of 1.4.

During the first 70 percent of the charge cycle, the charge efficiency of a NiCd battery is close to 100 percent. Almost all of the energy is absorbed and the battery remains cool. Currents of several times the C-rating can be applied to a NiCd battery designed for fast charging without causing heat build-up. Ultra-fast chargers use this unique phenomenon and charge a battery to the 70 percent charge level within a few minutes. The charge continues at a lower rate until the battery is fully charged.

Once the 70 percent charge threshold is passed, the battery gradually loses ability to accept charge. The cells start to generate gases, the pressure rises and the temperature increases. The charge acceptance drops further as the battery reaches 80 and 90 percent SoC. Once full charge is reached, the battery goes into overcharge. In an attempt to gain a few extra capacity points, some chargers allow a measured amount of overcharge