History of Batteries
1890 to 1914

1898 to 1908 -- the Edison Battery
Thomas Edison, the most prolific of all American inventors, developed an alkaline cell with iron as the anode material (-) and nickelic oxide as the cathode material (+). The electrolyte used was potassium hydroxide, the same as in modern nickel-cadmium and alkaline batteries. The cells were well suited to industrial and railroad use. They survived being overcharged or remaining uncharged for long periods of time. Their voltage (1 to 1.35 volts) was an indication of their state of charge.

This most remarkable battery is making a comeback after it was observed that many electric cars manufactured around 1912-1914 used nickel-iron batteries.   Some of these cars still have working Edison batteries on board.    The car below ran from 1912 to 1997 ON THE ORIGINAL EDISON BATTERIES! 

Car can be seen in 2008 a the BC Provincial Museum

In 1972 the Exide Battery Co. bought the manufacturing process for nickel iron batteries from the Edison Storage Battery Company.   It was taken out of production within 2 years.   Yet this battery remains the very best choice for solar homes since the battery pack may outlive the purchaser, if not the house.    They are also the most environmentally friendly of all storage batteries and contain no heavy metals.

Although it is out of production in NA, the Ni-Fe battery is in production in China and Romania.   They are being imported by two USA based companies for use in Solar homes.  

Ironically in 1972 a Japanese car using an improved version of the Edison cell had a range of 200km and a highway speed rating.   During this time the Japanese government had spent close to 20 million dollars on electric car research.   The Ni-Fe battery electrodes were improved to lower the internal resistance (the usual drawback of this chemistry.)  

For solar homes and wind generation systems the Ni-Fe battery is unmatched for environmental friendliness and robustness.   Not bad for a battery designed over a century ago.

1893 to 1909 -- the Nickel-Cadmium Battery
In parallel with the work of Edison, but independently, Jungner and Berg in Sweden developed the nickel-cadmium cell. In place of the iron used in the Edison cell, they used cadmium, with the result that it operated better at low temperatures, self-discharged itself to a lesser degree than the Edison cell, and could be trickle-charged, that is, charged at a much-reduced rate. In a different format and using the same chemistry, nickel-cadmium cells are still made and sold.

In 1906, Jungner established a factory in Sweden to produce flooded design nickel-cadmium batteries.

But I thought the NiCad dated back only to about 1958 ... that is when, as a child, I saw the first rechargeable flashlights.   Turns out the the NiCad battery was kept out of the NA market for almost a half century.