TM 11-6140-203-14-4&P
(3) Constant-voltage method.
(2) Charging a new battery with RF80GT.
Charge for 1 hour in accordance with procedures given
provides' the constant-voltage charging rate required for
in commercial literature and the following settings.
temperature, and the time to accomplish the charge
(a) Battery rating number switch Set on 3.
cycle For example, at a temperature of 800 F charge the
(b) Battery type switch. Set on A.
BB-693A/U for 2 hours at 30 volts or 4 hours at 29.0
(c) Battery cable. Use twin.
volts.
(Periodically,
monitor the constant-voltage
(d) Charge current (amps). Set on 60.
charging rate by placing the test prods of a voltmeter
across the battery terminal and adjust the output of the
NOTE
battery charger, as necessary.)
Use B setting for battery with appropriate
(4) Constant-current method The BB-693A/U
adjustments in charger time and current
can be charged either at one constant current rate as
if excess overheating and gassing
given in (a) below or a two steps constant current rate as
occurs during charge.
Check all
given in (b) below.
voltages at the beginning and end of
(a) Fixed constant-current rate
charge.
Check electrolyte level 30
Current (Amps) Time (hours)
minutes after charging; addition of water
15
3
is not required at this time unless no
11.5
4
electrolyte level is visible at the end of
9
6
charge.
7
7
Table 5-1. Constant Voltage charging Rate.
Ambient Temperature
2-hour Charge
4-hour Charge
8-hour Charge
Degrees
Constant Voltage
Constant Voltage
Constant Voltage
Fahrenheit
Centigrade
Per
BB-693 A/U
Per
BB-693 A/U
Per
BB-693 A/U
Cell
Cell
Cell
-40
-40
1.68
32.0
1.68
32.0
1.68
32.0
-20
-30
1.68
32.0
1.63
31.0
1.58
.0.0
0
-18
1.68
32.0
1.63
31.0
1.53
29.0
32
0
1.63
32.0
1.58
30.0
1.53
29.0
50
10
1.63
32.0
1.53
29.0
1.53
29.0
80
27
1.58
32.0
1.53
29.0
1.47
28.0
100
38
1.53
32.0
1.47
28.0
1.47
28.0
120
49
1.47
32.0
1.42
27.0
1.42
27.0
If the battery does not meet the minimum end of charge
accordance
with
procedures
of
voltage of 28.5-29.0 volts at temperatures of 50-90 F,
(1) Discharge capacity test. After charging (f
check individual cells for low voltage. If no low voltage
cells are present then change must be continued until
above), including a voltage and electrolyte level check,
the minimum voltages are reached. A new battery may
perform a capacity discharge using the procedure for the
require 20-30 percent more charge then normal units
AN/USM-432 ((a) below). The RF80GT ((b) below) or
very first charge.
resistor method ((c) below).
(b Two-step constant current. Charge
(a) The AN/USM-432 will discharge a
at 15 amperes to 29.0 volts. The reduce current to 6
battery at the preset 30 ampere rate until an end voltage
amperes and charge for an additional 2 hours.
of 0.95 V/cell is reached. Cell voltage should be
g. Performance Test. Performance testing for a
scanned during the 55th to 60th minute of the discharge
to look for low cells mark any cells which are under
new battery, before placing it into service, consists of
0.95V. If at least 60 minutes of discharge is obtained,
discharge capacity and electrical leakage tests. A
then PASS will be indicated and the charger-analyzer will
battery which passes both of these tests is considered to
automatically switch to final charge when the end voltage
be serviceable.
is reached. If the discharge is less than 60 minutes, the
NOTE
FAIL light is illuminated and the unit stops. The actual
Do not reject a battery or individual cells
capacity obtain, reported in minutes, should be recorded
within the battery which are slightly
on the battery service record card.
below minimum capacity without per-
(b) The RF80GT will discharge the
forming troubleshooting procedures and
battery at the preset 30 ampere rate until an end voltage
running two additional charge/discharge
of
cycles. Report defective new batteries
in
5-3
