he
temperature of the electrolyte were 80 deg. divide the difference between
80 deg. and 60 deg. by 2-1/2, or 80 deg. minus 60 deg. divided by 21/2 equals 8. The
gravity at 80 deg. would therefore be 1.225 minus .008, or 1.217, which is
the value of specific gravity to use. If the specific gravity is read
at a higher temperature than 80 deg., divide the difference between 80 deg.
and the temperature at which the gravity reading was taken by 21/2,
and add the result to the actual gravity reading obtained. If, for
example, the gravity were 1.225 at 100 deg., the gravity at 80 deg. would be
1.225 plus .008, or 1.233.

Charging Rates. The normal charging rate to be used in giving
Prest-O-Lite batteries a regular charge or overcharge are as follows:

Battery Charging Rate
------- -------------
5 F.P.L. 5.0 amps.
7 F.P.L. 7.5 amps.
9 F.P.L. 10.0 amps.
11 F.P.L. 12.5 amps.
13 F.P.L. 15.0 amps.
15 F.P.L. 17.5 amps.

Rebuilding Prest-O-Lite Farm Lighting Batteries

Opening the Cell.

1. Make sure that the cell is as fully charged as possible. Since it
is not very convenient to charge a single cell, a good time to open a
cell for cleaning and repairing is immediately after the battery has
been given an overcharge. See page 455.

2. Disconnect the cell from the adjoining ones.

3. Heat a thin bladed putty knife and insert it under the edge of the
lead-antimony cover to melt the sealing compound. Run the knife all
round the cover, heating it again if it should become too cool to cut
the compound readily.

4. Grasp the lead posts above the cover and lift up gradually. This
will bring up the cover, plates, and separators.

5. Place the plates on a clean board for examination. Use the
instructions given on pages 339 to 346. Do not keep the plates out of
the electrolyte long enough to let them dry, and the negatives heat
up. If you cannot examine the plates as soon as you have removed them
immerse them in 1.250 acid contained in a lead or non-metallic vessel
until you can examine them.

6. In renewing the electrolyte, pour in as much new 1.250 acid as
there was old electrolyte in the jar. (It is assumed that the
electrolyte was up to the lower ridge of the glass jar before the cell
was opened.) The new electrolyte must not have a temperature above
100 degrees when it is poured into the jar.

7. The separators can be pulled out easily when the plates are laid on
their sides. All that