Fig. 72.—The Wood Separator.
After they have thoroughly dried they should be assembled as in Figure 73 with one positive plate between two negative ones. The wooden "separators" are easily cut out of wood with a saw and penknife. The thin wood used in the construction of peach baskets is the best for the purpose. The separators should be made the same size as the lead battery plates.
Each group of plates is then placed in a jar containing a mixture of sulphuric acid and water (4 parts water to one part acid). In mixing the acid be very careful to pour the acid into the water, stirring the mixture slowly at the same time, and not the water into the acid.
Fig. 73.—The Complete Element for a Storage Cell.
The plates are now ready for "forming." The binding-posts on the lugs of the plates may be secured from the carbons of some old dry cells. The simplest method of "forming" the plates is to use four gravity cells and "form" one storage cell at a time.
Fig. 74.—A Battery of Home-Made Storage Cells.
Connect the positive pole (copper) of the gravity battery to the positive pole (center-plate) of the storage cell and the negative (zinc) of the gravity battery to the negative (outside plates) of the storage cell. Allow the current to flow through the storage battery for several days or until the positive plate turns to a dark chocolate-brown color and the negatives to a gray-slate.