Nickel Iron vs. Lead Acid - Off Grid battery debate

[msaine]

You are certainly entitled to your cynical opinion on the reason for the current state of NiFe. My personal opinion is that there are enough problems with NiFe, that have not been satisfactorily addressed, to explain their current obscurity.

But one very real problem which makes it harder for NiFe enthusiasts to get started and requires some extra work on their part is the very steep voltage versus SOC curve of the NiFe chemistry. This makes it difficult to extract anywhere near full energy from such a battery using existing inverters designed for Lead/Acid chemistry. Either customization of the inverter by changing the low voltage cutoff point (which may result in extra stress on the inverter and premature burnout), delivering too high a voltage to the inverter when the battery is at a high charge state (which has a high risk of burning out the inverter) or redesign of the inverter to handle a wider range of input voltages in normal operation. (To some extent you are more likely to get away with running the inverter at a lower voltage if you do not go anywhere near its full rated output power.)
Or else (shudder) using additional cells and relays to keep the voltage of the battery string high as the SOC decreases. This is arguably the best way to deal with the transition between net charging and net discharge from the batteries, but has enormous problems when dealing with reduced SOC situations.

Another approach is switching one or more voltage dropping diodes in and out of the circuit, but the energy wasted in them can be quite large!

So what your saying is don't use a Leadacid designed charger for NIFE. Sort of like using a NiCad charger to charge LiIon. You can do it, but you better have a fire extinguisher handy. So saying NIFE is not good because you can't use a Leadacid charger system doesn't say anything about NIFE be a bad system, just a harder one to support.

Just takes a more enlightned designer to address NIFE charging. These days that just means a little attention to programming in the charger!

Lead is poison, acid is dangerous, Iron and nickel aren't. But I wouldn't want to take a bath in NIFE electrolyte either

[msaine]

Do you care to retract your own statement now, or do I need to make you eat your words later? Your choice, I will give you 6 hours before I embarrass you and make you eat your words. Ball is in your court.

Nothing to retract. Once they are filled orginally, they only require distilled water to top off for evaporation. They have a Base "electrolyte" that does not need replenishing over their life time. Repeated charge/discharge cycles do not affect the electrolyte. Thus no hazarodous chemicals to deal with during maintenance. Can you say that for LEAD ACID? Also the newer designs incorporate a sealed cap system that retains water so even that maintenance is reduced.

Also what happens in a bank of lead acid cells when a unit goes bad? You cannot simply drop in a new battery, there is a balancing problem then. NIFE do not have this problem.

BTW these forums are not battle grounds so whats with the attitude? Are you so shallow that you have to bully people with views that don't match your own?

[inetdog]

I think you are over looking a couple of points concerning NIFE batteries vs Lead acid. Given, the up front cost of NIFE is higher, but the long term costs (which is what a smart person would consider for a solar system) is considerably lower for NIFE. They outlast leadacid by decades, they do not require hazardous chemicals to maintain. A set of Lead acid batteries will last (if your lucky and if you don't over charge them,10 Years ) whereas the NIFE's from the days of Edison are still viable. They simply do not wear out, they only require distilled water to replenish fluids lost, are immune to over charge problems of Lead, and for the proper system design are far superior to other technologies for length of service and maintenance. Many Railroad NIFE battieries are still in service since the early 1900's.

The reason US manufactures quit making them is simple: They don't wear out! what profit is there in selloing a product the consumer doesn't have to replace?

We in this country are way to used to equipment that is designed to be replaced. Ever consider the simple weed wacker? Most have a 1 year warranty, thats about 40 hours of operation to design for. Then throw it away and buy a new one!

You are certainly entitled to your cynical opinion on the reason for the current state of NiFe. My personal opinion is that there are enough problems with NiFe, that have not been satisfactorily addressed, to explain their current obscurity.

But one very real problem which makes it harder for NiFe enthusiasts to get started and requires some extra work on their part is the very steep voltage versus SOC curve of the NiFe chemistry. This makes it difficult to extract anywhere near full energy from such a battery using existing inverters designed for Lead/Acid chemistry. Either customization of the inverter by changing the low voltage cutoff point (which may result in extra stress on the inverter and premature burnout), delivering too high a voltage to the inverter when the battery is at a high charge state (which has a high risk of burning out the inverter) or redesign of the inverter to handle a wider range of input voltages in normal operation. (To some extent you are more likely to get away with running the inverter at a lower voltage if you do not go anywhere near its full rated output power.)
Or else (shudder) using additional cells and relays to keep the voltage of the battery string high as the SOC decreases. This is arguably the best way to deal with the transition between net charging and net discharge from the batteries, but has enormous problems when dealing with reduced SOC situations.

Another approach is switching one or more voltage dropping diodes in and out of the circuit, but the energy wasted in them can be quite large!

[Sunking]

they do not require hazardous chemicals to maintain. they only require distilled water to replenish fluids lost,

Do you care to retract your own statement now, or do I need to make you eat your words later? Your choice, I will give you 6 hours before I embarrass you and make you eat your words. Ball is in your court.

[msaine]

Short sighted view on NIFE batteries

I do not think you will get many replies as NiFe are just unsuitable for RE applications. They are just too expensive, more than lithium, and extremely inefficient charge characteristics. I know of a couple of people who have toyed with the idea, but with a cost of $2 to $6/wh is just out of the question, plus 40% larger solar panel array to make up for the 65% charge efficiency just makes it unreasonable. Lead acid cost are $0.14/wh for a 10 year battery, and LFP is around $0.50/wh. No one in their right mind is going to pay 10 to 40 times more for a battery


For now and for the foreseeable future lead acid chemistry are king, and soon Lithium LFP may make their mark when prices come down some more and reasonable battery management systems enter the RE market.

I think you are over looking a couple of points concerning NIFE batteries vs Lead acid. Given, the up front cost of NIFE is higher, but the long term costs (which is what a smart person would consider for a solar system) is considerably lower for NIFE. They outlast leadacid by decades, they do not require hazardous chemicals to maintain. A set of Lead acid batteries will last (if your lucky and if you don't over charge them,10 Years ) whereas the NIFE's from the days of Edison are still viable. They simply do not wear out, they only require distilled water to replenish fluids lost, are immune to over charge problems of Lead, and for the proper system design are far superior to other technologies for length of service and maintenance. Many Railroad NIFE battieries are still in service since the early 1900's.

The reason US manufactures quit making them is simple: They don't wear out! what profit is there in selloing a product the consumer doesn't have to replace?

We in this country are way to used to equipment that is designed to be replaced. Ever consider the simple weed wacker? Most have a 1 year warranty, thats about 40 hours of operation to design for. Then throw it away and buy a new one!

[Hemonster]

Does the layer of oil (mineral or otherwise) solve the carbonation problem in the KOH electrolyte? Seems like it should as it would stop air from getting to it.
I suppose you don't want to use vege oil because it would eventually go rancid. Would sewing machine oil do the trick?

[Sundetective]

Your 400 Ah Seiden Ni-Fe Battery Cells

I just got a quote from Seiden battery in China for NiFe 400AHr cells at USD$200, or $0.42/whr.
Comparing this to a quote I got for high quality Enersys PbA 2.4V 1000AHr at USD434, $0.18/whr - or more like $0.36/whr if you account for 50% DOD.

Both are rated for 20 years or more (ie. >=8000 cycles). Note Wikipedia reckons PbA charge/discharge efficiency is 50/95%:

http://en.wikipedia.org/wiki/Lead%E2%80%93acid_battery

This means energy through put in/out of the cell is 47% efficient.

NiFe has 65/80% efficiencies.

http://en.wikipedia.org/wiki/Nickel%E2%80%93iron_battery

This means energy in/out is 52% efficient.

These numbers in pricing and efficiency would seem to indicate that NiFe and high quality PbA are about similar price points and efficiencies - however one is a lot less toxic. Of course the toxicity is well contained and really it boils down to if or not you have good recycling options, or if the cells have to be shipped to another country to be recycled (adding to disposal costs).

NiFe power density is far inferior to PbA, but for a solar setup of 48V with power output at 5kw, this is only 100A which is C/4 rating which is ok for the 400Ahr cell. This means that the amount of power you required (not energy) has an influence on the sizing of the battery - which is not really the case for PbA.

Even if PbAs are more efficient at other operating points, solar panels are getting cheaper - I'm getting mine at about USD$1.10/watt ... and they are only getting cheaper. Working out the irradiance of the area I'm in against total surface area and efficiency of panel and derating it over 20 years, I still think that the pricing of the NiFe's would rival that of a high quality PbA. If you use the energy while the sun shines, you don't get the penalty of battery inefficiency regardless of chemistry you choose - so only run the low power appliances at night.

Further note, I've read that PbA cells will usually have rapid deterioration of performance after rated capacity due to wear on the Pb plates. If sulphation occurs (low charge states), the reduction in capacity is usually permanent. With NiFe cells, you don't need a generator to return the battery state of charge back up to full (they are happy to remain at zero charge for extended periods) - you only need to size one to run your household power until the next sunny day comes along. It makes little sense to charge up the battery for discharge again, when you can contain the stored energy in the liquid fuel until it is required - far more efficient.

Cool the generator down by heating up the hot water cylinder and you can heat the house at the same time - a cogen system utilises that liquid energy far more efficiently again.

Best of all, don't use any chemical batteries - just use a thermal battery based on vege oil instead:

http://www.youtube.com/watch?v=duuk_r--lqU

Hope that helps to open your minds up to possibilities.

Hemonster,

It's nice to hear from you about Seiden. They are left out of the Nickel-Iron-Battery discussions most
of the time. Stephen Ellis at Zapp Works in Montana talks with them and Changhong once in a while.
Here's a <snip> from Stephen:

"The production process is the Varta pocket plate design originally from Germany and sold to both
Seiden and Sichang Changhong battery manufactures.
The Chinese batteries are rated by individual cell readings and not as a total battery system so the
ratings are not true."

Stephen is a real Pro though I have developed some serious differences with some of his thinking.
There are a number of 'higher authorities' but naturally Thomas A. Edison's certified research notes
wind up being number one with a lot of it - for some people.

Anyway if it's pretty much, a same-same battery making set-up you can get a whole lot more
information about the Changhong Ni-Fe batteries than you can about the Seiden Ni-Fe batteries.
There is a great deal of ongoing controversy involving the two Changhong resellers in America and
their practices right now. It's just beginning to really blossom.
They are just waiting for the next shoe to drop. ( the devils )
You can Google:

'John D'Angelo and Brandon Williams' if you have any interest.

The Ni-Fe subject has a painful amount of data and details to it and was a real puzzle to me for a
while with so many contradictions. Many written and some verbal conversations with people like
Changhong's PhD Battery Chemist have helped a lot. Plus documents from Changhong and elsewhere.
All known forum accounts that we could find for any year that we were able to read or translate.
It goes on. Even the Russian's have helped us. Some claim that Russia won't write back.
It was just the opposite.

There is always more to find out but plenty95 of various specifics have already been found in the
last 15 months or so. Also in years past but never as a project.
Getting it into some type of a report that is clear and doesn't drift can be a challenge.

As far as what you said I would reconsider your figures on Life Cycles and the Round-trip Ni-Fe Efficiency.
It's not that simple.
There is a very active thread in a Brother forum that is called:

'Nickel Iron (Ni-Fe) Battery Life Cycle Chart .. from the Manufacturer'

You can Google it if interested. Ni-Fe always has had potential that was not realized. Then and now.
A big part of the puzzle has been due to the many myths, jive, wives tales and (to be polite)
deliberate misconceptions systematically planted and promoted for profits by the Ni-Fe resellers.

It's up to you the buyer to find the truths out especially about the Electrolyte which is a complex,
long, drawn out, detailed and thankless story.

The thing is once a person gets hooked on the quest and they are up in years do they keep the findings
to themselves and 'take it with them'. Or give it up for present and future people that have an interest.
Keep in mind Hemonster that Ni-Fe is not that awful popular of a subject in most off-grid type forums.
Not yet. Not until a hybrid battery marriage swings through Solar Town someday.

Bill Blake

[Hemonster]

I just got a quote from Seiden battery in China for NiFe 400AHr cells at USD$200, or $0.42/whr.
Comparing this to a quote I got for high quality Enersys PbA 2.4V 1000AHr at USD434, $0.18/whr - or more like $0.36/whr if you account for 50% DOD.

Both are rated for 20 years or more (ie. >=8000 cycles). Note Wikipedia reckons PbA charge/discharge efficiency is 50/95%:

http://en.wikipedia.org/wiki/Lead%E2%80%93acid_battery

This means energy through put in/out of the cell is 47% efficient.

NiFe has 65/80% efficiencies.

http://en.wikipedia.org/wiki/Nickel%E2%80%93iron_battery

This means energy in/out is 52% efficient.

These numbers in pricing and efficiency would seem to indicate that NiFe and high quality PbA are about similar price points and efficiencies - however one is a lot less toxic. Of course the toxicity is well contained and really it boils down to if or not you have good recycling options, or if the cells have to be shipped to another country to be recycled (adding to disposal costs).

NiFe power density is far inferior to PbA, but for a solar setup of 48V with power output at 5kw, this is only 100A which is C/4 rating which is ok for the 400Ahr cell. This means that the amount of power you required (not energy) has an influence on the sizing of the battery - which is not really the case for PbA.

Even if PbAs are more efficient at other operating points, solar panels are getting cheaper - I'm getting mine at about USD$1.10/watt ... and they are only getting cheaper. Working out the irradiance of the area I'm in against total surface area and efficiency of panel and derating it over 20 years, I still think that the pricing of the NiFe's would rival that of a high quality PbA. If you use the energy while the sun shines, you don't get the penalty of battery inefficiency regardless of chemistry you choose - so only run the low power appliances at night.

Further note, I've read that PbA cells will usually have rapid deterioration of performance after rated capacity due to wear on the Pb plates. If sulphation occurs (low charge states), the reduction in capacity is usually permanent. With NiFe cells, you don't need a generator to return the battery state of charge back up to full (they are happy to remain at zero charge for extended periods) - you only need to size one to run your household power until the next sunny day comes along. It makes little sense to charge up the battery for discharge again, when you can contain the stored energy in the liquid fuel until it is required - far more efficient.

Cool the generator down by heating up the hot water cylinder and you can heat the house at the same time - a cogen system utilises that liquid energy far more efficiently again.

Best of all, don't use any chemical batteries - just use a thermal battery based on vege oil instead:

http://www.youtube.com/watch?v=duuk_r--lqU

Hope that helps to open your minds up to possibilities.

[Naptown]

4G is 90 miles away in the city. 3G is supposed to be active, a friend will be trying it out this week. and we'll see if a G spot will be the ticket.

fixed it for you

[john p]

Off grid. the idea of a long range wifi connection is not so good as it would be dependant on another person/business having a wi fi that you could connect into.? And if they turn it off???

[tandrews]

[Offgrid]

Get a long range wifi antenna,put that sucker nice n high with hopeful line of sight to a wisp on the edges of the city and you will be fine.I run with a antenna and it's cool,except that one darned tree lol.

[Mike90250]

4G is 90 miles away in the city. 3G is supposed to be active, a friend will be trying it out this week. and we'll see if a _G hotspot will be the ticket.

[john p]

If he is that far from"civilization" and grid electricity and land lines for phone then it may be a lot longer than a year before he will get 4g in that area.. We have same problem in Philippines 4g is available and they claim now covers 40% of POPULATION but it covers about 5% of the country.
From what I have learned you need to be very close to the tower with 4g to get those high speeds,
He could have a long wait for 4g and really a 3g modem costs just about nothing .. just only sign up for 1 yr contract if thats how its done there.

[Sunking]

Mike hold off if you can on 3G before you get locked into a contract. If you can wait for 4G LTE.

3G data download speeds are on the order of 1mb/s. 4G is 12 mb/s.

Here is the other perk of a 4G phone you can use it as a WiFi modem for all you toys like your computer, Play Station, laptop, ect... So hold off if you can. Otherwise you are going to hate yourself in say 1 year from now when 4G is available and you are stuck in a 3G contract.

Right now Verizon has the best 4G network, but ATT has more of it in service at the moment. It is just a matter of time before 3G is antiquated like analog cell was 5 years ago when 3G came out.