Storage Battery
a battery which when charged can be used for some time as a source of electric cursame result in less time, the Faure or "pasted" cells were invented. In these, a paste of lead oxide is spread on to a supporting grid of lead. On charging, the material on the positive plate is converted to lead peroxide, while on the negative plate it is reduced to spongy lead.
The Edison battery uses plates of iron and nickel in a bath of caustic potash.
The plates consist of shallow perforated tubes of nickel-plated steel, fixed in a sheet-steel grid. In the positive plate, the tubes are filled with alternate layers of nickel hydroxide and flaked metallic nickel. The negative plate contains po powdered iron oxide. The reactions which take place are represented by: 2NiO2 + Fe = Ni2O + FeO. During discharge, the reaction proceeds from left to right; that is, oxygen is transferred from the nickel oxide to the iron. On charging, the action is reversed, the higher nickel oxide being produced, while rent. Gautherot, in 1801, first conceived the iron oxide is reduced to iron. In the idea of such a battery. Faraday, other words, charge and discharge rein his "Researches," mentions its prac- sult in a transfer of oxygen from one ticality. However, it was left to Gaston plate to another, so that no change in Planté, in 1860, to construct a practical the specific gravity of the electrolyte storage battery.
Storage batteries are of two typesthose using lead plates in an acid medium and those using iron-nickel plates in an alkaline medium. The former are subdivided into the Planté cells and the Faure, or "pasted" cells.
The reaction which occurs in both the Planté and Faure cells is indicated by PbO2 + the following equation: 2H2SO4 Lead Oxide Sulphuric Acid PbSO4 + Lead + Pb Lead 2H2O + PbSO4 Water Lead Sulphate = Sulphate When the battery is being charged the reaction takes place from right to left; that is to say, the lead sulphate on the plates is decomposed, producing lead peroxide on one plate and spongy lead on the other, while sulphuric acid is added to the electrolyte, its specific gravity being thereby increased. When the battery is being discharged, the reaction is reversed and takes place from left to right. In other words, sulphuric acid is taken from the electrolyte to form lead sulphate on both plates, so that the specific gravity falls. In the Planté cell, the active material on the occurs. The chief advantages of the battery are its lightness and the fact that it can remain charged or discharged for any length of time without injury.
Its disadvantages are its high cost and its comparatively comparatively low efficiency.
The best advice to give as to the treatment of a storage battery is to follow the manufacturers' instructions. Although all makes of storage battery are built on the principles outlined above, each one has its own special features, and no one is so familiar with its peculiar requirements as the manufacturers. The following instructions apply, however, to all makes. Cells should never be over discharged, because, in the lead cell, when the terminal voltage drops below 1.8 there is a tendency for the plates to buckle and for an insoluble sulphate to be produced.
This process is known as "sulphation."
For similar reasons, the cell should not be allowed to stand discharged for any length of time. If a battery is not in use for several weeks, it should be charged at least once a month, and, better, once every two weeks. As the electrolyte evaporates, the cell should be re-filled with pure, distilled water.
The electrolyte should never be per- STORAGE BATTERY mitted to sink below the level of the top of the plate. The acid does not evaporate replaced with chemically pure sulphuric some is accidentally spilled, it should be replaced with chemically pure sulphuric acid of the specific gravity recomthe case of the Edison cell, a 21 per cent. solution of caustic potash is used instead the case of the Edison cell, a 21 per cent. solution of caustic potash is used instead of sulphuric acid. lawyer and diplomatist, born in Cincinlawyer and diplomatist, born in Cincin- Harvard in 1867, and began the practice of law in Cincinnati. He was elected to Congress in 1891, serving until 1895.
From 1897 to 1899 he was Minister to Belgium, and from the latter year until 1902 filled the same office in Spain. He was appointed Ambassador to Austria- Hungary in 1902. His alleged activity on behalf of the proposed elevation of Archbishop Ireland to be Cardinal, led to his dismissal from his post, in 1906.