Battery Testing - Toro Workman GTX Electric & Lithium Service Manual

Battery Testing

When testing batteries in the Workman GTX Electric, it
is important to periodically test all batteries. Proper per-
formance of the vehicle depends on all batteries being
in good condition. Testing will determine if one (or more)
of the batteries needs to be replaced.
1. The preferred testing procedure is to use the Lester
Electrical 36/48 Volt Battery Discharge Unit (Model
17770). This instrument puts a known discharge load
(56.25 Amps) on the battery pack until the battery pack
reaches 42 volts. A timer incorporated into the dis-
charge unit measures the time needed to reach that volt-
age level. Battery capacity and remaining life can be
determined from the test results. Refer to Discharge
Unit Operating Instructions for further information.
Other types of battery load testers can also be used to
test the Workman batteries. Many locally available bat-
tery load testers do not, however, have any adjustment
on the load that is put on the battery. Results received
from using load testers should follow the recommenda-
tions of the load tester manufacturer.
2. If the Lester Battery Discharge Unit (or other load
tester) is not available, an alternate battery test can be
done using a multimeter to perform a voltage test of
each battery. Use the following procedure:
A. For accurate voltage testing, allow batteries to re-
main idle (no charging, no discharging) for at least six
(6) hours and preferably 24 hours.
B. Open the battery circuit by carefully disconnect-
ing the conductors between the battery pack and ve-
hicle components (see Opening Battery Circuit in the
General Information section of this chapter). Then,
disconnect both cables from battery to be tested.
C. Measure the battery voltage with the multimeter.
Record battery voltage. The measured voltage will
determine battery state of charge.
D. If voltage reading is below 70% charged (see Fig.
43), charge battery and take voltage measurements
again. If voltage remains low after charging, consider
battery replacement.
3. A third option for battery testing is to perform a specif-
ic gravity test of the battery electrolyte using a hydrome-
ter. Use the following procedure:
IMPORTANT: Make sure the area around the battery
fill caps is clean before removing the caps.
Workman GTX Electric
A. Remove battery filler caps. Do not add water prior
to testing specific gravity of battery electrolyte. If
electrolyte level is low, add distilled water and charge
battery before performing specific gravity test.
B. Measure the specific gravity of each battery cell
with a hydrometer. Fill and drain the hydrometer two
(2) to four (4) times before drawing a sample. At the
same time, take the temperature of the cell.
C. Have enough electrolyte in the hydrometer to
completely support the hydrometer float. Record the
hydrometer reading and return the electrolyte to the
battery cell.
D. Repeat test for remaining battery cells.
E. Temperature correct each cell reading. For each
10 F (5.5C) above 80F (26.7C) add 0.004 to the spe-
o
cific gravity reading. For each 10F (5.5C) below 80F
(26.7C) subtract 0.004 from the specific gravity read-
ing.
Example: Cell Temperature
F. The temperature corrected specific gravity of all
battery cells should be 1.277 + 0.007. If low cell read-
ings exist (see Fig. 43), charge battery and take spe-
cific gravity readings again.
G. If specific gravity of any cells remain low after
complete charging, battery should be replaced.
Battery Charge
Level
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
Page 3A - - 35
Cell Specific Gravity Reading 1.245
ADD (20F above 80F)
Correction to 80F
Specific Open Circuit
Gravity Voltage
1.277 6.37
1.258 6.31
1.238 6.25
1.217 6.19
1.195 6.12
1.172 6.05
1.148 5.98
1.124 5.91
1.098 5.83
1.073 5.75
Figure 43
Electrical System
100F
0.008
1.253