are heavy and stiff, and once they are
bent or twisted they are put under a strain, and exert a great force
to straighten themselves. This action causes the cables to pull on the
terminals, which become loosened, and cause a leak, or break the cover.

[Fig. 30 Measure height of electrolyte in battery]

6. Inspect the Battery twice every month in Winter, and once a week in
Summer, to make sure that the Electrolyte covers the plates. To do
this, remove the vent caps and look down through the vent tube. If a
light is necessary to determine the level of the electrolyte, use an
electric lamp. Never bring an open flame, such as a match or candle
near the vent tubes of a battery. Explosive gases are formed when a
battery "gasses," and the flame may ignite them, with painful injury
to the face and eyes of the observer as a result. Such an explosion
may also ruin the battery.

During the normal course of operation of the battery, water from the
electrolyte will evaporate. The acid never evaporates. The surface of
the electrolyte should be not less than one-half inch above the tops
of the plate. A convenient method of measuring the height of the
electrolyte is shown in Fig. 30. Insert one end of a short piece of a
glass tube, having an opening not less than one-eighth inch diameter,
through the filling hole, and allow it to rest on the upper edge of
the plates. Then place your finger over the upper end, and withdraw
the tube. A column of liquid will remain in the lower end of the tube,
as shown in the figure, and the height of this column is the same as
the height of the electrolyte above the top of the plates in the cell.
If this is less than one-half inch, add enough distilled water to
bring the electrolyte up to the proper level. Fig. 31 shows the
correct height of electrolyte in an Exide cell.

Never add well water, spring water, water from a stream, or ordinary
faucet water. These contain impurities which will damage the battery,
if used. It is essential that distilled water be used for this
purpose, and it must be handled carefully so as to keep impurities of
any kind out of the water. Never use a metal can for handling water or
electrolyte for a battery, but always use a glass or porcelain vessel.
The water should be stored in glass bottles, and poured into a
porcelain or glass pitcher when it is to be used.

[Fig. 31 Correct height of electrolyte in Exide cell]

A convenient method of adding the water to the bat