SkyTrak 6036 Service Manual - Manual (Page 225)

Section 10. Electrical System
Model 6036 S/N 9B0499 and Before 10-31
Relation of Battery Temperature to Minimum Voltage
Temperature (21 °C ) (10 °C) (–1 °C) (–10 °C)(–18 °C)Below
70 °F & 50 °F 30 °F 15 °F 0 °F 0 °F
Above
Minimum
Voltage
9.6 9.4 9.1 8.8 8.5 8.0
• The battery is sufficiently charged when
the green dot in the built-in hydrometer is
visible. No further charging is required.
Shake or tilt the battery at hourly intervals
during the charging to mix the electrolyte
and see if the green dot appears.
• Battery charging consists of a charge
current in amperes for a period of time in
hours. Thus, a 25-ampere charging rate for
2 hours would be 50 ampere-hour charge to
the battery. In most cases, batteries
whose load test values are less than 200
amperes (see Battery Testing Procedure)
will have the green dot visible after at least
a 50 ampere-hour charge. Most batteries
whose load test values are greater than
200 amperes will have the green dot visible
after at least a 75 ampere-hour charge. In
the event that the green dot does not
appear after this amount of charging,
continue charging for another 50 or 75
ampere-hours. If the green dot still does
not appear, replace the battery.
The time required for a charge will vary due to the
following conditions:
• Size of Battery. For example, a com-
pletely discharged large heavy-duty battery
requires more than twice the recharging as
a completely discharged small passenger
car battery.
• Temperature. For example, a longer time
will be needed to charge any battery at 0 °F
than at 80 °F. When a fast charger is
connected to a cold battery, the current
accepted by the battery will be very low at
first, then in time the battery will accept a
higher rate as the battery warms.
• State-of-Charge. A completely discharged
battery requires more than twice as much
charge as a one-half-charged battery.
Because the electrolyte is nearly pure
water and a poor conductor in a completely
discharged battery, the current accepted is
very low at first. Later, as the charging
current causes the electrolyte acid content
to increase, the charging current will
2. Attach voltmeter and battery load tester
clamps to posts.
3. Remove surface charge from any battery that
has just been on charge IF THE GREEN DOT
IS VISIBLE. This includes batteries in the
vehicle having been charged by the vehicle
alternator.
Do not remove surface charge from
batteries that have been in storage. To remove
surface charge, apply a 300-ampere load
across the terminals for 15 seconds. Then turn
off load and wait for 15 seconds to allow the
battery to recover.
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 in the table below and
determine the minimum voltage which must be
maintained while the battery supplies a speci-
fied electrical load
5. Apply a 260 A load test. Observe voltage after
15 seconds with load connected; then turn off
load.
6. If voltage is below value determined in step 4,
replace battery.
7. If voltage is at or above value determined in
step 4, battery is good and may be returned to
service.
8. Check the charge acceptance of the battery
one more time before discarding it.
e. Battery Charging
1. Do not charge battery if hydrometer is clear or
light yellow; replace battery.
2. Charge rates between 3 and 50 amperes are
generally satisfactory as long as spewing of
electrolyte does not occur or 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
occurs or temperature exceeds 125 °F (52 °C),
the charging rate must be reduced or tempo-
rarily halted to permit cooling.