Battery Testing - Toro GroundsmasterR 4300-D Service Manual

Battery Testing

1. Conduct a hydrometer test of the battery electrolyte.
IMPORTANT: Make sure the area around the cells is
clean before opening the battery caps.
A. Measure the specific gravity of each cell with a
hydrometer. Draw electrolyte in and out of the
hydrometer barrel prior to taking a reading to warm--
up the hydrometer. At the same time take the tem-
perature of the cell.
B. Temperature correct each cell reading. For each
o o
10 F (5.5 C) above 80
specific gravity reading. For each 10
o o
low 80 F (26.7 C) subtract 0.004 from the specific
gravity reading.
Example: Cell Temperature
Cell Gravity
o o
100 F minus 80
o
(37.7 C minus 26.7
o
20 F multiply by 0.004/10
o
(11 C multiply by 0.004/5.5
ADD (conversion above)
o
Correction to 80
C. If the difference between the highest and lowest
cell specific gravity is 0.050 or greater or the lowest
cell specific gravity is less than 1.225, charge the bat-
tery. Charge at the recommended rate and time giv-
en in Battery Charging in this section or until
specific gravity of all cells is 1.225 or greater with the
difference in specific gravity between the highest and
lowest cell less than 0.050. If these charging condi-
tions can not be met, replace the battery.
2. Perform a high--discharge test with an adjustable
load tester.
This is one of the most reliable means of testing a battery
as it simulates the cold--cranking test. A commercial bat-
tery load tester is required to perform this test.
CAUTION
Follow the battery load tester manufacturer's
instructions when using a battery load tester.
A. Check the voltage across the battery terminals
prior to testing the battery. If the voltage is less than
12.4 VDC, charge the battery (see battery charging
in this section).
Electrical System
o o
F (26.7 C) add 0.004 to the
o o
F (5.5
100
1.245
o
F equals 20 F
o o
C equals 11.0 C)
o
F equals 0.008
o
C equals 0.008)
0.008
o
F (26.7 C) 1.253
B. If the battery has recently been charged, remove
the battery surface charge before performing the
load test. Disconnect the engine fuel stop solenoid to
prevent the engine from starting. Engage the starter
motor for ten (10) seconds to remove battery surface
charge. Reconnect the fuel stop solenoid.
C. Make sure battery terminals are free of corrosion.
D. Measure the temperature of the center battery
cell.
E. Connect a battery load tester to the battery termi-
nals following the load tester manufacturer's in-
structions. Connect a digital multimeter to the
C) be-
battery terminals.
F. Apply a test load of 295 amps (one half the Crank-
ing Performance rating of the battery) for 15 se-
o
F
conds.
G. Take a battery voltage reading after 15 seconds,
then remove the load.
H. Using the table below, determine the minimum
voltage for the cell temperature reading:
Minimum
Voltage
9.6
9.5
9.4
9.3
9.1
8.9
8.7
8.5
I. If the test voltage is below the minimum voltage in
the chart, replace the battery. If the test voltage is at
or above the minimum, return the battery to service.
Page 5 - - 46
Battery Electrolyte
Temperature
o o
70 F (and up) 21 C (and up)
o
60 F
o
50 F
o
40 F
o
30 F
o
20 F
o
10 F --12
o
0 F --18
Groundsmaster 4300--D
o
16 C
o
10 C
o
4 C
o
--1 C
o
--7 C
o
C
o
C