all
the old plates with a new coarse toothed hacksaw, a sharp key hole
saw, or any good saw which has a wide set, close to the post. This
separates the entire group of plates from the post in one short
operation. This method is much better than the one of sawing the
plates off below the connecting strap, and sawing or punching the old
plate ends out of the strap. See page 217 for instructions for welding
plates to the straps.

Work on the Jars

The work on the jars consists of removing any sediment which may have
collected, washing out all dirt, and replacing leaky jars. The removal
of sediment and washing should be done after the preliminary charge
has been given and the old electrolyte poured out unless the
preliminary charge was given with distilled water in the jars. The old
electrolyte need not be poured down the sewer, but may be kept in
stone or earthenware jars and used later in making electrical tests to
locate leaky jars.

Testing Jars

Remove all sealing compound from the jar by means of a hot putty
knife, finishing by wiping with a gasoline soaked rag. Inspect each
jar carefully under a strong light for cracks and leaks. If you know
which jar is leaky by having filled each cell with water up to the
correct level, when you made the first examination of the battery, and
then having it allowed to stand over night to see if the electrolyte
in any cell has dropped below the tops of the plates, no tests are
necessary, but if you are in doubt as to which jar, if any, is leaky,
you must make tests to determine which jar is leaky. If you know that
there is no leaky jar, because of the bottom of the case not being
acid eaten and rotted, it is, of course, not necessary to test the
jars.

One test consists in filling the jar within about an inch of the top
with old or weak electrolyte, partly immersing the jar in a tank which
also contains electrolyte, and applying a voltage of 110 or 220
between the electrolyte in the jar and the electrolyte in the tank in
which the jar is partly immersed. If current Vows, this indicates that
the jar is leaky.

[Fig. 220 Testing jar for leaks, using a 15-watt lamp in series
with test circuit]

Fig. 220 shows the principle of the test. A suitable box,--an old
battery case will do--is lined with sheet lead, and the lead lining
is connected to either side of the 110 or 220 volt line. The box is
then partly filled with weak electrolyte. The jar to be tested is
fill