In installations where the charging rate is fixed, the number of hours required to
charge the battery can be determined from the table.
Example:-If the specific gravity at the end of the show is 1.170 and the
charging rate is 14 amperes find in the left hand column "14 Amps" and run across
to the right to "1.170." This is the "10 Hrs." column. The battery should therefore
receive 10 hours charge (not more) before the next discharge. This 10 hour charge
can be given while the other battery is being used to run the show, or between
shows, as most convenient.
Keep lighted cigars and cigarettes and all flames away from the battery. (The gas
given off is explosive.)
Keep the battery connections tight.
Loose battery connectors will cause noisy reproduction similar to static in a radio
receiver. If the battery connections are loose enough to arc, they are liable to ignite the
explosive gas given off by the battery.
51. Care of Type XCR-19 Storage Batteries. -This type of battery is known as the high
gravity type. It is used on RCA Photophone equipments PG-1, and PG-2. (See Section 36.)
The purpose of the battery is to remove the "ripples" from the generator voltage. Batteries
used in this manner are said to be "floating", and require special care.
Keep the outside of the batteries clean and dry.
Keep the separators always covered with electrolyte. (Do this regularly by adding
only approved water (distilled if necessary). Keep the solution about onequarter of an
inch above the plates.
Use a hydrometer to determine the state of charge of the battery. (The specific
gravity of one cell ("pilot cell") can be used to indicate the state of charge of the battery.
The specific gravity when fully charged is between 1.270 and 1.285 and when discharged it
is 1.150.
Maintain the voltage across these batteries at thirteen volts while the equipment is
in use. This will cause the battery to remain fully charged. However if the specific gravity
falls below 1.230 increase the voltage to such a point (slightly above thirteen volts) as will
cause the battery to remain fully charged. If the electrolyte level in the battery drops at a
greater rate than about one quarter of an inch every two weeks and the battery remains
fully charged, the voltage being maintained is too high, and should be reduced slightly.
When reducing the voltage see that there is no discharge and measure the specific gravity
often.
If it is necessary to charge the battery do not exceed 9 amperes.
Keep lighted cigars, cigarettes, and all flames away from the battery. The gas is
explosive.
Keep the battery connections tight.
At least once every six months the battery should be given an equalizing charge. See
section 48.
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