Lull 944E-42 Service Manual - Manual (Page 682)

Electrical System
9.172 Model 644E-42/944E-42 Rev. 6/04
When starting the engine, allow the starter to crank for a
maximum of 15 seconds only, then wait a minimum of two
minutes to help avoid burning out the starter. Also, DO
NOT let the engine idle excessively, as low engine rpm
can also lead to battery discharge.
Keep the battery from freezing by maintaining a full
charge. A completely discharged battery will freeze at
18° F (8° C).
Distilled water may occasionally need to be added
through the vent filler caps on the top of the batteries. The
vent filler caps prevent loss of electrolyte from the
batteries and they contain small pressure activated vent
hole to permit escape of gas pressure. The vent holes
allow gas and pressure produced in the battery during
charging to escape.
The vents in the filler caps require keeping the battery in
an upright position to help prevent electrolyte leakage.
Tipping the battery beyond a 45° angle in any direction
can allow a small amount of electrolyte to leak out.
DO NOT exceed this 45° angle when carrying or installing
a battery.
The battery has top-post terminals. Keep the terminals
clean, and securely tighten clean cable clamps onto the
posts. Grease or special spray sealers may be applied
over the connections.
b. Visual Inspection of the Battery
Inspect for damage such as a cracked or broken case or
cover that could permit loss of electrolyte. If obvious
physical damage is noted, replace the battery. Handle the
battery with care. Determine the cause of damage and
correct as needed before installing the new battery.
c. Battery Load Test
1. Disconnect both the negative (-) battery cable (first),
and the positive (+) battery cable from the battery.
Make sure that the negative and positive battery
terminal posts are clean to help assure a good
electrical connection.
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 chart below 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, then turn off
the load.
Note: The accuracy of this test procedure depends on
closely following the load, time and temperature
specifications.
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.
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