SkyTrak 6042 Service Manual - Manual (Page 456)

Electrical System
9.86 Model 6042 Legacy Origin 7/02
c. Battery Load Test
1. Disconnect both the negative (–) battery cable (first),
and the positive (+) battery cable (Fig. 9-48, 1 and
2) from the battery. Make sure that the negative and
positive battery terminal posts are clean to help
assure a good electrical connection.
Figure 9-48 Battery Cable Connections
2. Attach voltmeter and battery load tester clamps to
the battery terminal posts.
3. Remove the surface charge from any battery that
has just been charged (by a battery charger or by
the vehicle alternator). DO NOT remove the surface
charge from a battery that has been in storage. To
remove the surface charge, apply a 300-ampere
load across the terminals for 15 seconds. Then turn
off the load and wait for 15 seconds to allow the
battery to recover and normalize.
4. Battery temperature should be estimated by touch
and also by the surrounding temperature it was
exposed to during the preceding few hours before
testing. Select the nearest estimated temperature
from the following chart, and determine the minimum
voltage that must be maintained while the battery
supplies a specified electrical load.
5. Apply a 260-ampere load test to check the charge
acceptance of the battery. Observe the voltage after
15 seconds with the load connected, and then
remove the load.
6. If voltage is at or above the value determined in
Step 4, the battery is good and may be returned to
service.
7. If voltage is below the value determined in Step 4,
check the charge acceptance of the battery one
more time before discarding it. If the voltage
continues to read below the value determined in
Step 4, replace the battery.
Note: The accuracy of this test procedure depends on
closely following the load, time and temperature
specifications.
d. Battery Charging
Charge rates between three and 50 amperes are
generally satisfactory as long as spewing of electrolyte
does not occur, or that the battery does not feel
excessively hot (over 125° F [52° C]). Battery
temperature can be estimated by touching or feeling the
battery case. If spewing of electrolyte occurs or
temperature exceeds 125° F (52° C), commonly referred
to as “boiling” the battery, the charging rate must be
reduced or temporarily halted to permit cooling. Failure to
do so will destroy the battery.
MA8410
1 2
Relation of Battery Temperature
to Minimum Voltage
Temperature Minimum Voltage
70° F (21° C) and above 9.6
50° F (10° C) 9.4
30° F (-1° C) 9.1
15° F (-10° C) 8.8
0° F (-18° C) 8.5