8. It is not necessary to remove the sediment from the bottom of the jar unless it is within one half inch of the bottom of the plates. If the sediment is to be removed, carefully pour off the clear electrolyte into a lead, hard rubber, or earthenware jar, if the electrolyte is to be used again.
9. If one or two of the plates in either positive or negative groups need to be replaced it is best to burn a new plate to the strap without removing the peened cover. This is done by blocking under the row of plate lugs with metal blocks after cutting off old plate and cleaning the surface of strap. Insert new plate, the lug of which has been cut about 1/4 inch short, to allow for new metal. Choosing small oblong iron blocks of suitable size, build a form about the plate lug which fits same well. Now with a torch and burning lead fuse the new plate onto the old strap. When cool remove and test joint by pulling and slightly twisting the plate at the same time.
Sometimes one group of a starting and lighting battery may be in sufficiently good condition to pay to combine it with a new group, but this condition will very rarely, if ever, be met in farm lighting cell service. We advise the replacement of the complete cell element if either group is worn out, for the cost of repairs and of new group will probably not be warranted by the short additional life which the remaining old group will give.
10. Putting Repaired Cell Back into Service. After having finished all necessary cleaning, replacement, or repairs, remove all old sealing material, return the element with attached lead cover to the cell jar. It is not necessary to reseal the cover to the jars this sealing is essential only for insurance against breakage or leakage in shipment.
Add through the vent plug opening sufficient cool acid of 1.250 Sp. Gr. to reestablish the proper electrolyte level, which means that the electrolyte is brought up to the lower moulded glass ridge near the top of jar.
Connect the cell with any other repaired cells and charge at normal rate already indicated under "charging rates" until dell voltage reads 2.5 or above, at 80°. The positive to cadmium voltage should be at least 0.10 volts less than cell voltage itself. When this condition is obtained cell may be replaced in operating circuit with others and should give satisfactory service.
EXIDE FARM LIGHTING BATTERIES.
Exide Farm lighting Batteries are made with sealed glass jars, open glass jars, and sealed rubber jars, each of which will be described.
Batteries with Sealed Glass Jars.
Two types with sealed glass jars are made, these being the Delco Light Type, and the Exide type.