Service Manual

Charging
To minimize possible damage to the battery and allow
t
he 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 shops.
CAUTION
Follow the manufacturer’s instructions when
using a battery charger.
1. Determine the battery charge level from either its
open circuit voltage or specific gravity.
Battery Charge
Level
Open Circuit
V
oltage
Specific
Gravity
100% 12.68 1.265
75% 12.45 1.225
50% 12.24 1.190
25% 12.06 1.155
0% 11.89 1.120
2. Determine the charging time and rate using the
manufacturer
’s battery charger instructions or the
following table.
Reserve Battery Charge Level
Capacity (Percent of Fully Charged)
(Minutes)
(Minutes)
75% 50% 25% 0%
80 or less 3.8 hrs 7.5 hrs 11.3 hrs 15 hrs
at at at at
3 amps 3 amps 3 amps 3 amps
81 to 125 5.3 hrs 10.5 hrs 15.8 hrs 21 hrs
at at at at
4 amps 4 amps 4 amps 4 amps
126 to 5.5 hrs 11 hrs 16.5 hrs 22 hrs
170 at at at at
5 amps 5 amps 5 amps 5 amps
171 to 5.8 hrs 11.5 hrs 17.3 hrs 23 hrs
250 at at at at
6 amps 6 amps 6 amps 6 amps
above 6 hrs 12 hrs 18 hrs 24 hrs
250 at at at at
10 amps 10 amps 10 amps 10 amps
CAUTION
tery warm to 60
o
F (15.5
o
C) before con-
Charge the battery in a well–ventilated
charging. These gases are explosive;
Nausea may result if the gases are in-
haled. Unplug the charger from the elec-
posts.
Do not charge a frozen battery because it
can explode and cause injury. Let the bat-
necting to a charger.
place to dissipate gases produced from
keep open flame and electrical spark
away from the battery. Do not smoke.
trical outlet before connecting or discon-
necting the charger leads from the battery
3. Following the manufacturer’s battery charger
instructions, connect the charger cables to the battery.
Make sure a good connection is made.
4. Charge the battery following the
manufacturer’s
battery charger 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 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 consecutive
readings.
Electrical System (Rev. G)
Page 6A
– 14
Groundsmaster 300 Series