Service Manual

Table Of Contents
Groundsmaster 4500D/4700D Page 5 55 Electrical System
Battery Charging
To minimize possible damage to the battery and allow
the battery to be fully charged, the slow charging meth-
od is presented here. This charging method can be ac-
complished with a constant current battery charger
which is available in most locations.
CAUTION
Follow the battery charger manufacturers
instructions when using a battery charger.
NOTE: Using specific gravity of the battery cells is the
most accurate method of determining battery condition.
1. Determine the battery charge level from either its
specific gravity or open circuit voltage.
Battery Charge
Level
Specific
Gravity
Open Circuit
Voltage
100% 1.265 12.68
75% 1.225 12.45
50% 1.190 12.24
25% 1.155 12.06
0% 1.120 11.89
2. Determine the charging time and rate using the bat-
tery charger manufacturer’s instructions or the following
table.
Battery
Reserve
Capacity
(Minutes)
Battery Charge Level
(Percent of Fully Charged)
75% 50% 25% 0%
80 or less 3.8 hrs
@
3 amps
7.5 hrs
@
3 amps
11.3 hrs
@
3 amps
15 hrs
@
3 amps
81 to 125 5.3 hrs
@
4 amps
10.5 hrs
@
4 amps
15.8 hrs
@
4 amps
21 hrs
@
4 amps
126 to
170
5.5 hrs
@
5 amps
11 hrs
@
5 amps
16.5 hrs
@
5 amps
22 hrs
@
5 amps
171 to
250
5.8 hrs
@
6 amps
11.5 hrs
@
6 amps
17.3 hrs
@
6 amps
23 hrs
@
6 amps
above
250
6 hrs
@
10 amps
12 hrs
@
10 amps
18 hrs
@
10 amps
24 hrs
@
10 amps
CAUTION
Do not charge a frozen battery because it can ex-
plode and cause injury. Let the battery warm to
60
o
F (16
o
C) before connecting to a charger.
Charge the battery in a wellventilated place to
dissipate gases produced from charging. These
gases are explosive; keep open flame and elec-
trical spark away from the battery. Do not smoke.
Nausea may result if the gases are inhaled. Un-
plug the charger from the electrical outlet before
connecting or disconnecting the charger leads
from the battery posts.
3. Following the battery charger manufacturer’s
instructions, connect the charger cables to the battery.
Make sure a good connection is made.
4. Charge the battery following the battery charger
manufacturer’s instructions.
5. Occasionally check the temperature of the battery
electrolyte. If the temperature exceeds 125
o
F (51.6
o
C)
or the electrolyte is violently gassing or spewing, the
charging rate must be lowered or temporarily stopped.
6. Three (3) hours prior to the end of the charging, mea-
sure the specific gravity of a battery cell once per hour.
The battery is fully charged when the cells are gassing
freely at a low charging rate and there is less than a
0.003 change in specific gravity for three (3) consecu-
tive readings.
Electrical
System