Renewable Energy Storage
Green Chemistry Stationary Battery
The Edison Nickel Iron Cell
Outlasts Lead Acid by Decades!

Lasting Energy Storage for
Solar, Wind & Micro-Hydro

Invented over 100 years ago by Thomas Edison
as a non-polluting and non-consumable alternative
 to Lead Acid Batteries using no heavy metals!         

-Now manufactured once again worldwide after lead acid battery
companies closed Edison's Plant in
1972 in East Orange, NJ USA.

This Information Is Provided by ...
The Nickel Iron Battery Association
-dedicated to clean energy storage for renewable energy systems.

Click Here to Read International Study of Lead Acid Battery
 Pollution from Solar Applications in India and China

Thomas Edison with his NiFe Cell
Thomas Edison with his Nickel Iron Battery in 1910

Building a solar, wind or other renewable energy system for a home or business can be discouraging if lead acid batteries need to be used.   Lead acid batteries are "consumables" and last only a fraction of lifespan of your solar panels or other electricity sources.   Massive battery banks of lead acid batteries need to be replaced every 10 years or less.   However a better solution has been available since about 1911 using the almost forgotten storage battery that contains no toxic heavy metals and may outlast you or your house!

The purpose of this site is to collect information that will help people to use and maintain the Nickel Iron Battery technology for use in Solar homes and for Marine applications.   The Nickel Iron battery often lasts in excess of 40 years and makes a perfect match for solar panels which also last for about 40 years or more.   This site is focused on the re-popularization of nickel iron batteries in renewable energy applications.   Nickel Iron Batteries contain no environmentally damaging heavy or poisonous elements.   The electrolyte of Potassium Hydroxide is caustic but can be useful in farming when diluted to neutralize acidic soils.

This site is not specific to a manufacturer or supplier.   Nickel Iron battery manufacturers or suppliers are welcome to list links to their websites.  This site supplies useful and accurate information on the Edison Nickel Iron Battery technology and its uses in alternate energy applications.  

Nickel-iron Battery Specifications
Energy/weight 30-50Wh/kg
Energy/size 30 Wh/l
Power/weight 100W/kg
Charge/discharge efficiency 65% - 85%
Energy/consumer-price 1.5– 6.6Wh/US$
Self-discharge rate 10-15% /month
Time durability 30– 100 years
Cycle durability Repeated deep discharge does not reduce life significantly.
Nominal cell voltage 1.2 V
Charge temperature interval min.-40°C
max.46 °C

The nickel-iron battery (NiFe battery) is a storage battery having a nickel(III) oxide-hydroxide cathode and an iron anode, with an electrolyte of potassium hydroxide. The active materials are held in nickel-plated steel tubes or perforated pockets. It is a very robust battery which is tolerant of abuse, (overcharge, overdischarge, and short-circuiting) and can have very long life even if so treated. [6] It is often used in backup situations where it can be continuously charged and can last for more than 40 years.   Due to  its high cost of manufacture, other types of rechargeable batteries have displaced the nickel-iron battery in most applications.  Because of their long life NiFe batteries are ideal for backing up renewable energy applications.  The reason for their disappearance in the North American market is largely due to the Exide Corporation's decision to abandon the technology in 1975 after purchasing it from the Edison Storage Battery company for several million dollars.   The reason for acquiring the manufacturing process to make NiFe batteries and then simply abandoning the technology is unknown.   Exide remains the second largest manufacturer of lead acid batteries in the world. 

(If anyone knows more about why Nickel Iron batteries went out of production in North America please contact us and we will update this website.)

Charging Parameters

The proper float voltage is 1.45 volts per cell.    If 10 cells were used, the proper charge voltage would be 14.5 volts. 

The charge voltage can vary from 1.46 to 1.55 volts per cell.   Unlike other battery designs, the exact charge voltage is unimportant.   A higher voltage will result in quicker charges but more water loss that will necessitate more frequent topping up with distilled water.    Since the cells can withstand overcharge there is debate over what constitutes a proper charge voltage.     The higher you go the quicker water will disappear from the batteries.   At voltages greater than 1.5 volts/cell the batteries will store approximately 15% more power than they are rated for.   If 10 cells were used, the charge voltage could range from 14.6 volts to 15.5 volts.   It is probably better to use the 1.46 volts / cell level of charge in order to minimize water loss if the battery will be unattended for months at a time.   Regenerative catalytic caps are available to combine the h2 and o2 back into water if unattended maintenance is required.   There are also auto watering systems that are available.
The proper equalization voltage is 1.65 volts per cell.   If 10 cells were used, the proper equalization voltage would be 16.5 volts.  This equalization charge is applied for 8 hours using at least C/10 current.   According to Edison's original manual from 1914, it is best to completely discharge the batteries from time to time before applying the equalization charge.   Edison also recommends a 1.7 volt equalization charge and he recommends  changing the electrolyte every 5-10 years.

This will all come as a surprise for lead acid battery users.   In contrast to lead acid, the NiFe battery can be overcharged for decades at a time without damage and can be left discharged for years at a time and will still work perfectly when needed.


The ability of these batteries to survive frequent cycling is due to the low solubility of the reactants in the electrolyte. The formation of metallic iron during charge is slow because of the low solubility of the Fe3O4. While the slow formation of iron crystals preserves the electrodes, it also limits the high rate performance: these cells charge slowly, and are only able to discharge slowly. [6] Nickel-iron cells should not be charged from a constant voltage supply since they can be damaged by thermal runaway; the cell internal voltage drops as gassing begins, raising temperature, which increases current drawn and so further increases gassing and temperature.

Nickel-iron batteries have long been used in European mining operations because of their ability to withstand vibrations, high temperatures and other physical stress. They are being examined again for use in wind and solar power systems and for modern electric vehicle applications.


The half-cell reaction at the cathode:

2 NiOOH + 2 H2O + 2 e ↔ 2 Ni(OH)2 + 2 OH

and at the anode:

Fe + 2 OH ↔ Fe(OH)2 + 2 e

(Discharging is read left to right, charging is from right to left.)[7]

The open-circuit voltage is 1.4 volts, dropping to 1.2 volts during discharge. [6] The electrolyte mixture of potassium hydroxide and lithium hydroxide is not consumed in charging or discharging, so unlike a lead-acid battery the electrolyte specific gravity does not indicate state of charge. [6] Lithium hydroxide improves the performance of the cell. the voltage required to charge the cells is between 1.6 and 1.7 volts.  Most people use 1.65 volts.


Swedish inventor Waldemar Jungner had invented the nickel-cadmium battery in 1899. Jungner experimented with substituting iron for the cadmium in varying proportions, including 100% iron. Jungner had already discovered that the main advantage over the nickel-cadmium chemistry was cost, but due to the poorer efficiency of the charging reaction, Jungner never patented the iron version of his battery.

The nickel iron battery was developed by Thomas Edison in 1901, and used as the energy source for electric vehicles, such as the Detroit Electric and Baker Electric. Edison claimed the nickel-iron design to be, "far superior to batteries using lead plates and acid" (lead-acid battery).  Both Edison and Ford worked together on electric cars prior to the World War One.

Jungner's work was largely unknown in the US until the 1940s, when nickel-cadmium batteries went into production there. A 50 volt nickel-iron battery was the main power supply in the World War II German V2 rocket (together with two 16 volt accumulators which powered the four gyroscopes), with a smaller version used in the V1 flying bomb. (viz. 1946 Operation Backfire blueprints.)

1912 Detroit Electric Car with NiFe Battery
Several early car manufacturers offered nickel iron batteries at the turn of the 20th century.  NiFe batteries were a more expensive option and most of these cars owned by collectors such as Jay Leno still contain functioning NiFe storage batteries constructed prior to World War One.   The Royal BC Museum in Canada contains a working car as does the BC Hydro museum.
detroit electric car 1912
Nickel Iron Battery Still Functioning after almost 100 years

Manufacturing from 1903

Edison's batteries were made from about 1903 to 1972 by the Edison Battery Storage Company located in East Orange, NJ. They were quite profitable for the company. In 1972 the battery company was sold to the Exide Battery Corporation, which discontinued making the battery in 1975.   The Eagle-Picher Company of the UK advertised in 1970 a nickel iron car battery that would "last as long as all the cars you own in a lifetime".  They purchased the cells for their battery from Edison's company.   They also proposed their application in all electric vehicles in the early 1990s.  Perhaps this was the stimulus to bury the Edison Storage Battery Company.   No one really knows why the Exide Battery Company killed the technology in North America by 1975.

It is interesting to note that all railways from 1910 to 1965 or so used nickel iron batteries in the caboose to run all the lights on the train. Yet technical literature on batteries such as Audel's New Electric Library only mention lead acid batteries starting in 1945.  It is even erased in Audel's guide from the section on the history of batteries.   So it would appear that nickel iron battery knowledge was no longer being published in technical guildebooks by the end of the second world war.    Yet V2 rockets during the second world war were nickel iron battery powered.  The reason for this disappearance from the technical literature is a mystery.

Edison was disappointed that his battery was not adopted for starting internal combustion engines and that electric vehicles went out of production only a few years after his battery was introduced. He actually developed the battery to be the battery of choice for electric vehicles which were the preferred transportation mode in the early 1900s (followed by gasoline and steam). Edison's batteries had a significantly higher energy density than the lead acid batteries in use at the time, and could be charged in half the time, however they performed poorly at low ambient temperatures.   The battery enjoyed wide use for railroad signalling, fork lift, and standby power applications.  By simply changing the electrolyte to a higher concentration of KOH the modern manufacturers have achieved low temperature operation.   In situations where a lead acid uncharged battery might suffer freezing damage, a nickel iron battery will not be damaged at all.

There are now USA, Chinese and Russian manufacturers of NiFe batteries.  Nickel-iron cells are currently made with capacities from 5 Ah to 1000 Ah. Many of the original manufacturers no longer make nickel iron cells but new manufacturers started appearing in the last 20 years.

Environmental impact

Nickel-iron batteries do not have the lead or cadmium of the lead-acid and nickel-cadmium batteries, which makes them a lesser burden on human and ecological health.  There are in use for solar homes today mainly in Australia.

Example Chicago USA Off Grid with Nickel Iron Batteries
            (some from 1930s and still ticking!)
Click to Read Report
off grid in
              Chicago home

Example Canadian Solar Home with Nickel Iron Storage

solar home showing panels nickel iron cell
700 Watts of Solar Panels                     200 Amp Hour Nickel Iron Cell
maximum power point
        controllernickel iron batteries
Maximum Power Point Controller
set to Nickel Iron          Nickel Iron Battery Bank in Garden Shed

Remote Village Power in China
Project costs are much lower with NiFe as compared to lead acid battery systems
when you take into account the replacement of spent batteries.  NiFe cells
last 20-40 years in this application. even with deep discharges.

land delivery of batteriesboat delivery of batteries


nife cell array

Historic Technical Literature on NiFe Batteries
1/ Edison published a nickel iron maintenance guidebook in 1914 ... click here to download his manual.
2/ Eagle-Picher advertsement for their Nickel Iron car and Electric Car batteries.

Current Research on Nickel Iron Batteries

The University of Michigan and the University of Victoria are doing research on the application of Nickel Iron Batteries.   The University of Victoria is doing research on the use of magneto-hydrodynamic (magnetic agitation) processes to increase the efficiency into the 90% range for NiFe batteries through the work of Dr. Robert O'Brien.    The University of Michigan is doing research on the local manufacturing of NiFe batteries in developing countries because of the environmentally friendly chemistry.   The results of these research projects will be reported here during 2010.

Modern Research to Rejuvenate 85 Year Old Edison Cells

Thomas Edison suggested that his Nickel Iron Cells would last 100 years.    A battery researcher in the USA has recently during 2011 rejuvenated some 85 year old cells produced by Edison.    He was able to restore them to a useable state even after 85 years ... so it would seem it was not an idle boast of Edison's that they would reach 100 years!

Here is the research paper to right click and save ... Rejuvenating an 85 year old battery pdf.

Open Source Concepts for Future Research on the Edison Cell
1/  Storing the Hydrogen
Another new area that a number of people are working on is the re-design of the Nickel Iron battery case so that the hydrogen generated during the charging of a nickel iron battery can be collected and saved for cooking, lighting or fuel cell operation to generate electricity from the stored hydrogen.  Thus the generation of hydrogen during charging can become an asset.

This was Ian Soutar of Microsec R&D Inc.'s idea originally and is being published here as a "public disclosure" to prevent the possibility of anyone patenting the concept.   These few paragraphs constitute the first public disclosure. 

Nickel Iron batteries are based on a Potassium Hydroxide (KOH) solution for the electrolyte.    Hydrogen generators that are commercially avaiable also use a KOH solution and nickel or stainless steel electrodes.  Thus the Edison cell almost certainly could be able to double as a hydrogen generator as well!   Anyone is free to fly with this idea ... as long as they realize that this concept is now in the public domain and will not be patentable.    If anyone can master it this will be a great breakthrough that can provide for reliable and limitless decentralized local storage of electricity.  The Nickel Iron battery can be overcharged for decades without damage as it merrily bubbles out its hydrogen.    We only need to figure out how to collect it without affecting the battery function.

-Ian Soutar of Victoria BC Canada holds the copyright (Sept 2009)) for these ideas to be distributed for free public use subject to the restrictions of the GPL3.

2/ Stopping the Generation of Hydrogen
Microsec R&D Inc. is also doing research in Victoria BC Canada on the use of catalytic caps (containing platinum wool) for the battery cells that recombine the hydrogen and oxygen released during charging into water and allows it to drip back down into  the cells.    This may eliminate the need to water the batteries regularly.   These caps are available for lead acid batteries but have a short lifespan due to the sulphur present in the sulphuric acid electrolyte.    However the Nickel Iron chemistry contains no poisons for the platinum catalyst and they might last indefinitely with NiFe.   If this works it would open the way to manufacture sealed nickel iron batteries.  Attempts to create sealed Nickel Iron Batteries have so far not been found due to the release of hydrogen.   This is the first public disclosure of the concept and it is open to everyone to play with without patenting issues holding back the research.    This application would preclude the collection of hydrogen of course.

-Ian Soutar of Victoria BC Canada holds the copyright (April 2010) for these ideas to be distributed for free public use subject to the restrictions of the GPL3.

These concepts are presented in the spirit of the General Public Licence or GPL3 that is usually applied to software. Below is a link to the licencing concept to be used for the above ideas.

Everyone is encouraged to add to this collection of research ideas for the improvement of the Edison Cell.

The reason for this public disclosure is evident in the new Lithium Iron Phosphate batteries, where the chemical patent is owned by  A123Systems (   The ownership of this amazing chemical invention remains locked into ownership by one group and the result is a very expensive battery that will remain expensive for 20 years.   This inhibits the adoption of alternate energy technologies at a time when their adoption is critical.

Nickel Iron Battery Supplier Homepages Changhong Battery Manufacturer in China USA supplier of NiFe batteries USA manufacturer and supplier of NiFe batteries in Montana

            USA Supplier of NiFe battery systems, Resource for historical information   Canadian Supplier of ChangHong batteries, Victoria BC AGO Environmental Electronics in Canada (custom orders, also sells hydrogen fuel cells)   Kursk Accumulator Plant NiFe Manufacturer in Russia


Small Sized NiFe Samples 10AH @ 1.2 volts
(for Educational and Industrial Battery Researchers
Newly manufactured samples of nickel iron cells nominally 1.2 (one point two volts) available for $50 each including shipping within North America to researchers. This service is being offered only to battery researchers.   Charging and maintenance instructions shipped with each and technical assistance is available.

Please write to Ian Soutar of Microsec R&D Inc ...

Exciting Research on Nickel Iron Batteries
Journal of IEEE 1995 showing that cycling of the battery does not reduce capacity.
(Shows that scienfic tests validate the long lifespan of NiFe cells.)
Journal of Applied Electrochemistry 2005 ... First Sealed Nickel Iron Battery Design Successful.
(Shows that NiFe cells can be sealed like rechargeable flashlight batteries.)

External Links Wikipedia Article on NiFe Batteries

Hosted by the Nickel-Iron Battery Association
Open to all Nickel Iron battery manufacturers and suppliers worldwide.
There is no charge to post your commercial NiFe supply webpage.
-we are looking for modern NiFe battery research links ... we can post your research results.

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Site Updated August 24, 2012

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