International Harvester Company TD-24 Operator's Manual page 85

MAINTENANCE
ELECTRICAL SYSTEM - Continued
•
b. Specific gravity readings should not
be made immediately after water has been
put into the batteries; take readings either
before the water is added or after the bat-
teries have been o_ncharge for some time.
c. All cells should show approximately
the same specific gravity reading. Wide vari-
ation indicates something wrong. See your
International Industrial Power distributor
or dealer.
d. The specific gravity reading of the
electrolyte in a fully charged battery SHOULD
, , NOT EXCEED the value specified by the man-
- ufacturer.
If the specific gravity of a battery
seems excessively high, refer to your Inter-
national Industrial Power distributor or
dealer.
e. Acid or electrolyte should never be
a dded except by a skilled battery man. Under
no circumstances add any special battery
"dopes", solutions or powders.
9.
EFFECT OF LOW TEMPERATURES
ON BATTERY PERFORMANCE. Battery
capacity is greatly reduced by cold, as cold
has a de cide driurnbtng effect on the e.le ct.ro;
chemical action in the battery. The follow-
ing 'comparison indicates the reduction in
cranking power of a fully charged battery
when the ternpe ra.tur e of the electrolyte,drops
from 800.F. to 320 F. and to 0 OF.
80
0
F.
100'10
6510
0
0
F.
4010
10. COMPARISON OF POWER RE-
QUIRED TO CRANK EN:GINEAT DIFFER-
ENT TEMPERATURES. The power required
to crank the engine is greatly increased by
cold, as indicated in the following chart. The
comparison is based on atmospheric tem-
peratures of 800 F., 320 F., and 00. F., and
crankcase lubrication with SAE-20.
80
0
F.
100%
165%
250%
11. DANGER OF BATTERIES FREEZ-
ING WHEN NOT FULLY CHARGED. It is
impo r tant to keep the batteries
close to full
charge in cold weather operation, to avoid
the danger of freezing. The electrolyte of
a battery will start to freeze (first ice crys-
tals begin to appear in the electrolyte, al-
though it does not freeze solid, until a lower
temperature is reached) approximately as
indicated below (specific gravity readings
corrected to 800 F.):
1.250 sp. gr.
1.200 sp. gr.
1.150 sp. gr.
1.100 sp. gr.
· Freezes at - 60
0
F.
· Freezes at - 150 F.
· Freezes at
+
50 F.
· Freezes at
+
200 F.
12. BATTERY VOLTAGE. With the
batteries fully charged and on charge at the
normal rate, the average cell voltage at
800 F. ranges between 2.5 and 2.7 volts; at
1000 F. it ranges between 2.4 and 2.6 volts.
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