tention has been paid to its upkeep;
whether it has been charged regularly and given an overcharge once a
month; whether distilled water has been used in replacing evaporation
of water from the electrolyte; whether impurities such as small nails,
pieces of wire, etc., have ever fallen into any cell; whether battery
has ever been allowed to stand in a discharged condition for one day
or more; whether temperature has been allowed to rise above 110 deg. F.
at any time; whether electrolyte has ever been frozen due to battery
standing discharged in very cold weather.

3. Talk to the owner long enough to judge with what intelligence he
has taken care of the battery. Doing this may, save you both time and
subsequent embarrassment from a wrong diagnosis resulting from
incomplete data.

4. After getting all the details that the owner can supply, you will
probably know just about what the trouble is. Look over the cells
carefully to determine their condition. If the jars are made of glass
note the following:

(a) Height of sediment in each jar.

(b) Color of electrolyte. This should be clear and colorless. A
decided color of any kind usually means that dirty or impure water has
been added, or impurities have fallen into the cell. For discussion of
impurities see page 76.

(c) Condition of plates. The same troubles should be looked for as in
automobile batteries. See pages 339 to 346. An examination of the
outside negatives is usually sufficient. The condition of the
positives may also be determined if a flash light or other strong
light is directed on the edges of the plates. Look for growths or
"treeing" between plates.

(d) Condition of separators. See page 346.

If cells have sealed rubber jars, proceed as follows:

(a) Measure height of electrolyte above plates with glass tube, as in
Fig. 30. If in any cell electrolyte is below tops of plates that cell
is very likely the defective one, and should be filled with distilled
water. If a considerable amount of water is required to fill the jar
it is best to open the cell, as the plates have probably become
damaged. If the jar is wet or the rack is acid eaten under the jar,
the jar is cracked and must be replaced.

If you have not found the trouble, make the following tests, no matter
whether glass or rubber jars are used:

(a) Measure specific gravity of each cell. If any cell is badly
discharged it is probably short-circuited, or contains impurities and
had better b