TO 31S9-4-38-1 Chg 3
figure. The power rating of the resistor should not be below
at temperatures below 100° .(37.77° .) and three intervals
that given in the figure.
for items operating at temperatures above 100° .(37.77'C.).
Expected battery service life should be 2 to 4 years below
100° .(37.77° .) and 1 to 3 years above 100° .(37.77° .).
Be sure switch SI is in open or OFF
position prior to connecting battery.
d. Testing of Batteries.
(6) Close switch S1, and after a period of 5 ± 1
seconds note and record the voltage on the voltmeter.
The battery may generate amounts of
Before turning the
POWER switch to OFF or performing any
Do not allow switch, S 1 ro remain closed
maintenance action on any operating J-
for a period exceeding 10 seconds and
do not use the text fixture shown in
rechargeable battery, open the enclosure
figure 7-3 above a 10%duty cycle rate,
door and allow the unit to ventilate for a
i.e., the ratio of "off" time to "on" time
minimum of two minutes. Do not smoke
should not be less than 9: 1.
in the vicinity of the unit while opening
(7) Compare the voltage obtained in (6) above
the door or ventilating.
with those given in the following table:
(1) If the battery is installed in an operating
Control Unit, observe the above warning and then place the
Above 65° . (18.33° .)
POWER switch to OFF. Disconnect the battery leads and
55 to 65° . (12.77 to 18.33° .)
remove the battery from the enclosure.
45 to 55° . (7.22 to 12.77° .)
(2) Visually inspect the battery. It should be free
35 to 4S° . (1.66 to 7.22° .)
of any evidence of physical damage such as cracks in the
25 to 35° . (3.88 to 1.66° .)
case or obvious leakage of the electrolyte. Discard if physical
15 to 25° . (-9.44 to -3.88° .)
damage is evident. For batteries contained in an operating
5 to 15° (-15. to 9.44° .)
component, the battery should be no more than 2-3° .(-
-5 to 5° . (-20.55 to 15° .)
16.66° --16.11° .) above ambient temperatures. Any battery
-15 to -5° . (-26.11 to -20.55° .)
in an operating component which is hot to the touch or which
-20 to -15° . (-28.88 to -26.11° .)
exhibits case deformation caused by excessive heat is an
(8) Discard any battery whose voltage is below
indication that a battery, or power supply failure has occurred.
that specified in the table.
Discard the battery and verify proper power supply operating
e. Recharging Batteries with Auxiliary Battery Charger.
prior to installing and operating for an extended period of time
If it is necessary to recharge the battery utilizing a battery
with a new battery.
charger or power supply other than that in the Control Unit the
(3) Connect the battery to an AN/GSM-64C (FSN
following procedures 'should be followed.
6625-00-02-7894) voltmeter observing proper polarity.
(1) The charging voltage must be maintained
Discard any battery whose open circuit
between 30 and 31 volts d.c.
terminal voltage is less than 18.00 volts.
(2) The charging current into the batteries must
(4) Recharge new batteries either by (1) charging
be limited below 3.000 amps either with an adjustable current
the battery in accordance with the instructions in e below or by
limit in the power supply (this is the preferred method) or by
(2) (preferred method) installing the battery in a Control Unit
placing a 50 watt resistor of between 2 and 4 ohms in series
and allowing the power supply to recharge the battery for a
with the battery. The exact value of the resistor will vary
minimum of 24 hours. After this 24 hour recharge period,
depending upon the length of time that has elapsed since the
disconnect the battery leads and remove the battery from the
battery was last charged and storage temperature.
The value of resistance which must be
If method (2) is used, do not close the
used to limit the current will decrease as
enclosure door. Allow the Control Unit
the battery becomes charged. When the
free standing ventilation during this 24
battery is initially placed on charge use a
4 ohm resistor and verify that the current
(5) After recharging connect the battery to a
is below 3.000 amps. Once the battery
switch, resistor and AN/GSM-64C voltmeter as shown in
figure 7-3. Be sure the leads to the AN/GSM-64C are
connected directly to the battery terminals as shown in the
Change 3 7-14