I am reposting this is a better area of the forum.
In Canada the Nickel Iron Battery is being looked at once again for solar homes. The In Europe the flooded Nickel Cadmium battery is about to be banned. Nickel Iron will be the replacement. The Chinese have put 20 years of research and manufacturing into this type of battery. In India they have developed a sealed Nickel Iron Battery that may be appropriate for cars and boats.
The Nickel Iron Battery is absolutely ideal for solar homes. The Wiki site now shows the true data for Nickel Iron Batteries. It is simply not true that they have a high discharge rate that affects solar home operation. The little discharge that occurs over a week is completely offset by the new energy is arriving daily The discharge rate is about 30% / month or about 1% per day ... very insignificant for solar applications.
The newest of the NiFe batteries are from China where over 20 years of research has gone into perfecting them. Why was NiFe abandoned in NA? Very simply it was driven out of the country by lead acid battery manufacturers who were horrified at a battery that lasted for 30 to 50 years on the average!
Here are the facts about their discontinuation in North America ...
1/ The Edison Storage Battery Company was formed in 1910 approximately by Thomas Edison. It was a very profitable company selling batteries for Canadian and USA trains until about 1972. The batteries were also used extensively in Canadian and USA mines for emergency power and for underground trains. Yet many sites claim that NiFe batteries do not work in the cold! Why then would they be used amost exclusively on Canadian trains from 1920 to 1972?
2/ The Edison Storage Battery Company was bought by the Exide (Lead Acid) Battery Company in 1972. The shareholders of Exide were told that Exide would begin manufacturing their own NiFe batteries soon.
3/ In 1975 the Exide Battery Company pulled Nickel Iron Batteries off the market and ceased manufacturing them completely by 1975.
There were many criticisms of Nickel Iron Batteries on this site ... almost all of them based on poor facts and no first hand knowledge of the batteries. Here is where the facts are found ...
The Nickel Iron Battery Association
You will see my house there with NiFe backup power for leading edge LED lights. I bought the components for the lights from http://www.ledsupply.com. Since my battery system varries from 20 volts to 36.4 volts I had to use a constant current source DC to DC supply from Digikey ... the LED supply ones would only handle 32 volts.
Check out the leading edge research in India from 2005 that succeeded in creating a sealed NiFe battery (thought to be impossible until then).
I have been using a NiFe battery system now for 6 months and the NiFe cells are simply amazing. I have charged them without a controller for the first few weeks ... overcharging them like crazy. Then I discharged them right to zero. They came back up and were improved in the energy storage capacity. Currently I am experimenting with a Maximum Power Point Controller from Outback using 80 volts of panels to charge a 30 volt system.
The rule of thumb for nickel iron is ...
They loved to be overchaged and be worked hard!
For solar homes NiFe batteries should be the standard.
Environmental Danger of Lead for Solar Home Proliferation
Suppose 1 million solar homes get built using 500 kg of lead acid batteries. It is estimated that in NA 3% of lead acid batteries never make it to recycling. That would mean that 15 million kilograms of lead ends up in rivers lakes and landfill sites every 10 years or so. If this actually happened no one could claim that solar homes were environmentally friendly!
With Nickel Iron batteries solar can be totally fully environmentally friendly. The expired KOH electrolyte can be used for cleaning barns (it is used for this by farmers) or it can be diluted down and used to neutralize acid soils. Nickel and Iron are very harmless compared to lead. The NIFe battery is not a consumable like a lead acid battery is!
It is true that under heavy load the voltage will go down ... but not by much ... they still produce enough current at a reasonable voltage to drive an inverter. In our experimental home we used DC power exclusively and high efficiency LED lighting. If you want to use an inverter, KiPoint (I think they are in Taiwan) will do a custom one. I discharge the nickel irons from 36.4 volts (equalize voltage) all the way down to 20 volts. I am about to order a custom inverter that can handle the almost 2/1 drop in voltage over a discharge and still produce a clean 120 VAC. It will only be used for a few appliances since we are slowly converting that house to run on DC,
So please ... do not assume the NiFe battery is dead. It is just like the movie "who killed the electric car?" The Nickel Iron Battery was considered by Edison to be the very best invention of his life. It was killed by the Exide Battery Company who also published false literature concerning its characteristics. Jay Leno owns two of the 1912 Detroit Electric cars and one of them is still running on the original NiFe battery! Does that sound like a battery that is useless!
Time to wake up the forum concerning Nickel Iron. There is much to discuss.
Vancouver Island BC.