1916 Cadillac - GM Heritage Center

ADJUSTMENTS ADJUSTMENTS 53
AMMETER
When the ear is standing with lights turned on. the ammeter, which is
located on the instrument board, indicates on the "Discharge" side of the
dial the amount of current being drawn from the storage battery for this
purpose. When the ignition switch is turned on the ammeter indicates, in
addition, the current used in slowly rotating the armature of the motor generator.
When the starter button is pushed down current is no longer required
for slowly rotating the armature of the motor generator. The ammeter
then indicates only the current used for the ignition and lights (if turned on).
The ammeter does not indicate the amount of current used in the cranking
operation.
Before the engine is running fast enough to generate sufficient current
to equal the current demand, the ammeter indicates on the "Discharge" side
the amount of current being drawn from the storage battery. When the engine
has attained a speed sufficient to generate current to more than equal
the demand, the ammeter indicates on the "Charge" side the excess current
which passes to the storage battery and recharges it.
Ordinarily, with all lights switched off. sufficient current is generated to
start recharging the battery when the car is operated in high gear at speeds
between four and six miles per hour and, of course, at much lower speeds
when the car is operated in low or intermediate gear. With all lights turned
on sufficient current is generated to take care of the requirements at a speed
of ten to fifteen miles per hour and at speeds greater than this the surplus
current passes through the storage battery and recharges it. In other words,
the ammeter indicates the rate at which the storage battery is being charged
or discharged.
To determine the total output of the generator turn off all the lights and
add the amount of current used for ignition, i. e., two to three amperes, to
the ammeter reading.
STORAGE BATTERY
The storage battery used with the Cadillac Delco Electric Cranking.
Lighting and Ignition System is designed especially for it, and is made by
The Electric Storage Battery Co., of Philadelphia, Pa., whose products for the
trade are known as "Exide" batteries.
The Electric Storage Battery Company, whose general offices and works
are at Alleghany Avenue and 19th Street, Philadelphia, Pa., has service
stations in towns of any considerable size where battery repair work is
done, as well as sales offices and Exide battery depots in a number of the
larger cities of the country where complete assembled batteries and repair
parts are carried in stock. For the location of the nearest Exide depot or
service station write the local Cadillac dealer or, if preferred, the Electric
Storage Battery Company, at Philadelphia.
The Storage Battery (Fig. 13) consists of three cells, each cell containing
thirteen (13) plates—six positive and seven negative.
When the battery is fully charged, the electrolyte or solution in the cells
should have a specific gravity of from 1.270 to 1.290 as indicated by the hydrometer
syringe (Fig. 15). The gravity will lower, due to discharge, and when
completely discharged, will register from 1.150 to 1.170—about 120 points less
than when fully charged. If one cell regularly requires more water than the
others, thus lowering the gravity, a leaky jar is indicated. Even a very slow
leak will in time relieve the cell of all its electrolyte. A leaky jar should
immediately be replaced by a new one.
The gravity is an indication of the state of charge of the battery. _ A
battery discharged below a specific gravity of 1.150 will not "crank" the engine,
nor will it burn the lights to full candlepower when the engine is not in
operation.