Nickel Iron FAQ

Frequently Asked Questions about the Nickel Iron battery in Home Power Systems:

This is a MUST read if you have never heard of these batteries!

updated 01/23/2016

General Information

Q: When were nickel iron batteries invented and why?

A. The nickel-iron battery was invented in the early 1900's by Thomas Alva Edison (1847-1931). The US patent number is 827,297 and was filed on July21, 1904 and granted to the Edison Battery Storage Company on July 31, 1906. The battery was intended for use as the propulsion system for electric cars.

They were put on the market and then withdrawn because the battery did not perform as well as he wanted them to. After reintroducing them, the battery enjoyed a long outstanding life until 1972 at which time Exide Battery Corporation bought the Edison Battery Storage company. Once Exide purchased the company they made them until about 1975 and then withdrew them from the market.

Edison also believed in DC and "on site" power. That is, power transmitted very short distances from small DC generating plants located close to the electrical needs of the end user.

Q: Are nickel-iron batteries made in the USA?

A: At this time (Jan 2016) a USA company called Encell makes a nickel iron cell. However, the cell was developed for the aircraft industry and not designed for deep cycling that a home power system requires. Independent testing of the cell was not very good. encouraging. The cell i also only 100 Amp hours and that  and a home power system normally requires 300-500 Ah battery capacities which mean that you have to have a lot of cells if you use small 100 cells to give you a 300-500 Ah battery bank.  

A company in Montana is taking original cells and placing them in polypropylene (PP)  containers. Their warranty is only 2 years (from their web page as of 1/16/16)  That is wonderful that they take the original cells and refurbish them. But we really do not know how long a refurbished nickel iron cell will last. We know how along original cells last - up to 80 years. Here is an article on someone who got some old cells for free and bought them back to life. 

BeUtilityFree, Inc. imports these nickel-iron batteries from China and has been importing them since 1995. No other company knows these cells like we do.

Q: Will Be Utility Free ship batteries internationally?

A: Yes! Our batteries are carefully packaged so that they can be shipped anywhere on the planet! If you have an address we can ship them to you. WE have shipped to Spain, Israel, and other countries.

Q: How long will the old and your new nickel-iron battery last?

A: The old original nickel iron batteries are a lot like a solar electric module. No one knows how long a PV module will last, but they have been working since the early 1950's when they became commercially available. Some original batteries that were manufactured by Edison's company are still in use today in applications such as mines, railroads and home power systems. We have access to the coding that the company used and by the markings on the top of the cell, we can determine the manufacture date and also the amp-hour capacity of the battery. Many of the original batteries are still in service after over 60 years! Some cells that were 70 years old still produce 100% of their rated capacity!

The manufacturer claims that their batteries will last up to 20 years with a regular discharge of 50% of the battery's rated capacity. Our guess is that they will last up to 40 years with a few electrolyte changes and less discharge. Electrolyte replacement is inexpensive when compared to battery replacement! The original cells made by Thomas Edison have more nickel content in their cells than the new cells made in China. From our experience, so far, this does not seem to be a factor in the new cells longevity. In fact we have recently extended our warranty from 10 to 15 years on material and workmanship reflecting our confidence in the new China cells. We have also added a battery capacity warranty similar to the power output warranty PV manufacturers give on the power output of their PV modules.

Q: Can they be used with the latest solar equipment such as "off grid" and "on grid" inverters, solar electric arrays and solar charge controllers?

A. YES! Almost all popular inverters built today like the Schneider Electric (Xantrex), Exceltech, Magnum, and Outback inverters can be used with them. The only type of inverter that cannot be used with nickel iron cells is the type that has a FIXED voltage range and where the voltage of the inverter is NOT adjustable. These type of inverters are specifically designed for lead acid batteries. One can also adjust the cells in your system to "fine tune" the battery cell voltage with the inverter. They can also be used with the latest solar charge controllers that use maximum power point tracking (MPPT) technology. As of 6/12/12 we are recommending the MIdNight Classic Model 150 or 200 solar charge controller becuase it has a setting for nickel cadmium battereis which basically have the same charterictics of our nickel iron battey. All solar electric modules on the market can be used to charge nickel iron cells either with or without a charge controller as long as the voltages match the battery voltage.


Installation and Maintenance Information

Q: What voltage do the cells produce?

A: They have a nominal voltage of 1.2 volts per cell. A battery is made up of a group of cells to get the desired end voltage. For example a 12 Volt system usually requires 10 cells. A 24 volt system requires 20 cells and so on. With higher operating voltage range of a nickel iron battery one can usually drop one cell to obtain a better charge of the battery. A lead acid battery has a nominal cell voltage of 2 Volts, thus for the same voltage output fewer cells are needed in a lead acid battery. 

Q: What type of maintenance is required on these batteries? 

A: It is minimal. Make sure the cell tops are dry and clean. Hose them off (if needed) them once a year and keep the water level up in the battery with either manual watering or with an automatic battery watering system. We also suggest a once a year equalize charge which is a controlled overcharge of the battery.

Q: What amperage do these batteries produce?

A: They start at 100 amp-hours (C/5rate) and go up to 1200 amp-hour cells (at a C-5) rate. You can put these batteries in series/parallel to obtain almost any amp-hour amount you need for a home power system or other needs. We do not recommend more than two sets in parallel.

Q: How do they perform in cold weather?

A: Cold weather has little effect on these batteries. However no home power battery should be stored in a cold area. All batteries prefer a warm climate. 77 degrees is ideal but 72 works about as well. Since nickel iron batteries have NO corrosive fumes like a flooded lead acid battery does then they can be put in a living environment area. But generally most battery banks are located outside or in area away from a normal living area. Keep batteries at a constant temperature for longest life. Fluctuating temperatures cause stress on the battery plates

Q: Will they need to be stored when I'm away from my summer cabin?

A: They are IDEAL for a cabin environment. Even if it is completely discharged, a nickel-iron battery will not freeze. When you return for the summer simply charge them back up! You cannot do this with lead-acid batteries without shortening their life or risking the batteries freezing and bursting. Unlike nickel-iron batteries, the sulfuric acid in lead-acid batteries releases water when discharged, making for a serious freeze hazard.

Q: What type of electrolyte is in these batteries?

A. Potassium hydroxide (KOH) and some lithium hydroxide (LiOH) mixed with distilled water. The water is about 85% of the fluid. The electrolyte is less caustic than the electrolyte in lead-acid batteries, but it's an alkali, so it's best to be cautious anyway.  LiOH mixed in water is benign enough that it doesn't require a Materials Safety Data Sheet.  Potassium Hydroxide (PH 13).  Take a look at the anhydrous LiOH MSDS here PDFand the anhydrous KOH MSDS here.  Remember that adding water to a strong acid or alkali will cause an exothermic reaction that could mean boiling, splashing  hot chemicals getting all over the place!  Always put acids or bases into water, not the other way around!

Q: What type of container do these cells battery come in?

A: All cells (a battery is a group of cell connected in series) we sell now come in translucent ABS plastic containers. We have found PP and MBS containers that other companies selling nickel iron cells are extremely difficult to see the electrolyte levels so we no longer sell the these case. The original nickel iron cell came in metal welded nickel plated steel containers. Why? We believe there where two reasons. 1) plastic technolgy was not to the state is is today so they kept with what they new best: steel. 2) Their markets where mainly mobile markets. Railroads, mining cars, cars themselves. Very few where used in home power systems. Almost 100% of our cutomers use our batteries in home power systems where strength of the cell container is not "high" priority. The battery just sits on a rack and never moves.


More Information

Q: How efficient are these batteries?

A: They are about 75% percent efficient on an energy in and energy out basis. he efficiency factor varies becuase fo cell charging rates and the cell operating temperaturers. As they age their efficiency flat lines until their useful life is up. Lead-acid batteries continually lose their battery capacity with age, so you waste less energy charging a 10 year old nickel iron than a 10 year old lead acid. If you have a back up generator then you also use far less fuel over the life of the battery. Why have to run a back up generator for 10 hours or more when you can run that same generator 5 hours to do the same thing? The cells are rated at a C/5 rate which means you can charge a 100 AH battery set for 20 amps for 5 hours. For that same 100 AH lead acid battery set yu woudl have to charge it up at a rate of 5 amps (a C20 rate - 100/20 = 5) for 20 hours. 

Q: Do these batteries need to be vented?

A: No, because they do not give off sulfuric acid gases like flooded lead acid batteries. However, if you wish to vent them there is no reason not to! Batteries should be enclosed for safety reasons and to keep the dust and dirt from collecting on the cells. So if you enclose these cells inside a battery box then you should vent them. Normally most NiFe cells are not put in battery boxes like lead acid batteries are. These cells also come with plastic covers (see pictures on our web site)  that go over the battery posts unlike lead acid batteries which do not have this feature.

Q: Do you need to use a charge controller on these batteries?

A: Normally, yes because of the new MPPT charge controllers get more power out of your array when you need it the most - winter time. and using a charge controller generally cuts down on battery watering periods.

If these batteries are used on a daily basis, one can actually bypass a charge controller and may be able to get  more energy into your battery bank but do not know that as a fact. If you do use a charge controller, it is best to use an MPPT (maximum power point tracking) charge controller. When you do not use a charge controller and your loads are light and the batteries are not used much, you will usually use more water than if you use a charge controller. We highly recommend a self-watering gravity system on ALL battery banks for maximum life. 

Q: What type of battery charger can I use?

A: Most people having on grid and off grid systems use the built-in battery charger from your inverter or use a separate battery charger. These chargers usually need to be adjusted for higher charging voltages which is easy to reprogram. The cells have to be charged at 1.65 volts per cell. We sell specific battery charges that have a wider voltage range than your typical lead acid battery charger, but we have been succesful with charging these cells off of regular automotive type chargers they just take longer to charge. We now have a line of AC chargers that can plug into your back up AC generators that have the proper charge volatges. We are also exploring a line of direct DC charging form an ICE source. However teh best way to charge yoru batteyr bank is with solar electricity.  

Q: Where can I buy these "lifetime" batteries?

A: BeUtilityFree imports these batteries and has been doing so since 1995. Please contact us. If the amp hour size you desire is not in stock we can add it to our next order. 


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