BA–10.—This battery consists of a single cell, of the “reserve” or “desiccated” type, commercially known as the No. 6 size. The cell is cylindrical and is contained in a paraffined cardboard carton. The hollow carbon rod and the zinc can are provided either with spring terminals, as Fahnestock or other clips, or with binding posts. The cell is about 6 inches high and 2-1/2 inches in diameter. Its weight when dry is about 1 pound and 12 ounces or 1.76 pounds. It has an open-circuit voltage of between 1.55 and 1.60 volts, an internal resistance of between 0.05 and 0.10 ohms, an almost in definite shelf life in the dry condition and 6 to 8 months in the wet condition, and a service life which depends entirely on its use. The short-circuit current is about 23 amperes. This cell is of the same size, etc., as BA–17 (see par. 84), which, however, is not of the desiccated type, and the two can be used interchangeably. It must be remembered that a BA–10 cell is “dead” when supplied and that water must be added before it can deliver current. Before adding the water, be sure that any broken pieces of cork or carbon which are loose in the hollow carbon electrode are removed. Instructions such as the following are generally printed on the carton: This cell will require about 33 ounces of water for charging. When charging, fill the carbon electrode with water and add water as fast as it is absorbed during one hour; after the first hour, water should be added at intervals of thirty minutes until about 33 ounces have been used. Allow the cell to stand for one hour after the last addition of water and then pour out all excess water which remains in the electrode. Such a cell can, however, be used immediately if necessary, but the full voltage and current will not be attained for several hours. When filling the cell with water, care must be taken not to have an excess of water on top of the sealing compound, as this may short-circuit the cell. The battery is at present used by the Signal Corps interchangeably with BA–17 in the following equipment:
- BD–9–A. Monocord switchboard.
- BD-11-A. Similar to above.
- BD–14. Camp switchboard.
- EE–13. Standard wall telephone, fire-alarm telephone system.
- EE-14. Buzzer instruction set.
- EE–25. Composite wall telephone, plotters type.
- EE–26. Composite artillery telephone, desk type.
- EE–27. Similar except wall type.
- EE–28. Similar except portable type.
- Training Pamphlet no.7 Primary Batteries Jun., 1922 W.D.D. NO. 1112