Cadillac V-63 1923 Operator's Manual page 34

60
GENERAL CARE
from iron pipes generally contains iron and other metals in solution, which
will ultimately cause trouble if used.
Fig. 24. Hydrometer Syringe
Hydrometer Syringe
A hydrometer (Fig. 24) is an instrument for testing the specific
gravity of a liquid. A hydrometer syringe is a hydrometer specially
designed for convenience in testing the specific gravity of the acid solution
in storage batteries. Hydrometer syringes are not a part of the electrical
system but can be purchased from any "Exide" service station.
To test the solution in the storage battery with a hydrometer syringe,
proceed as follows:
Remove the filling plug from the cell to be tested, compress the rubber
bulb of the syringe, and insert the pipette into the solution of the cell.
Hold the syringe as nearly vertical as possible, and gradually lessen the pres-
sure on the bulb until enough of the acid solution is drawn into the syringe
to float the hydrometer. The specific gravity reading is taken on the hydro-
meter at the surface of the acid solution in the glass barrel.
If the acid solution is below the top of the battery plate, or so low that
it is not possible to draw enough of the solution into the barrel to float the
hydrometer, fill the cell to the proper level (see Fig. 23), by adding pure
water, run the engine until the water has become thoroughly mixed with
the acid solution, and then take the reading as above described. The engine
should run for several hours after water is added before an hydrometer
reading is taken.
Preparing Battery for Winter Storage
When the car is stored for the winter the level of the acid solution should
be even with the bottom of the filling tubes. (See under "Adding Water
to Storage Battery," page 59.) If water is added it should be added just
before the last time the car is used so that it will be thoroughly mixed with
the acid solution. When the car is stored, the specific gravity of the acid
should register from 1.270 to 1.290. In this condition there is no danger
of the acid solution freezing. The specific gravity of water is 1.000 and
water freezes at 32 degrees F. above zero.
Unless the battery is fully charged or nearly so it is probable that the acid
solution in the battery will freeze and cause extensive damage.
GENERAL CARE , 61
The following is a table of the freezing temperatures of sulphuric acid
and water solutions of specific gravities from 1.050 to 1.300.
Specific Gravity Freezing Temperature
(Hydrometer Reading) (Degrees Fahr.)
1.050 +27°
1.100 +18°
1.150 + 5°
1.164 0°
1.200 —17°
1.250 —61°
1.275 to 1.300 —90°
The battery should be charged every two months during the "out of
service" period, by running the engine. If the above is impossible and there
is no garage equipped for charging batteries to which it may be conveniently
sent, the battery may be allowed to stand without charging during the
winter, provided the specific gravity of the acid solution registers from 1.270
to 1.290 at the time the car is laid up. Much better results and longer life
from the battery will be obtained by giving the periodic charges.
The wires of the battery should be disconnected during the "out of
service" period, as a slight leak in the wiring will discharge the battery.
Placing Battery in Service Again
If the battery has received periodic charges it will be unnecessary to
give it any special attention, other than to fill it to the proper height with
distilled water and connect the wires which were disconnected when the
car was stored. After the car has been driven for a number of hours, the
specific gravity of the acid solution should be taken with a hydrometer
syringe. The solution should register from 1.270 to 1.290 if the battery is
fully charged.
A greenish deposit sometimes exists on the terminals of a storage bat-
tery which has been stored. This deposit may be removed with a solution
of bicarbonate of soda (common cooking soda) in water. Do not allow any
of this solution to get into the cells of the battery.
If the battery has not been kept charged during the winter, it is advisable
to remove it from the car and give it a fifty-hour charge at a 4-ampere rate,
before putting it into service again. This should be done at a plant equip-
ped to take care of the work.
Sediment
The sediment which gradually accumulates in the bottom of the jars,
should be removed before it reaches the bottom of the plates. The need of