user manual

Groundsmaster 4100--D Page 5 -- 39 Electrical System
2. Conduct ahydrometertest ofthe batteryelectrolyte.
IMPORTANT: Make surethearea around the cellsis
clean before opening the battery caps.
A. Measure the specific gravity of each cell with a
hydrometer. Draw electrolyte in and out of the
hydrometerbarrel priorto takinga readingto warm--
up the hydrometer. At the same time take the tem-
perature of the cell.
B. Temperature correct each cell reading. For each
10
o
F(5.5
o
C) above 80
o
F (26.7
o
C) add 0.004 to the
specific gravity reading. For each 10
o
F(5.5
o
C) be-
low 80
o
F (26.7
o
C) subtract 0.004 from the specific
gravity reading.
Example: Cell Temperature 100
o
F
Cell Gravity 1.245
100
o
F minus 80
o
F equals 20
o
F
(37.7
o
C minus 26.7
o
C equals 11.0
o
C)
20
o
F multiply by 0.004/10
o
F equals 0.008
(11
o
C multiply by 0.004/5.5
o
C equals 0.008)
ADD (conversion above) 0.008
Correction to 80
o
F (26.7
o
C) 1.253
C. If the difference between the highest and lowest
cell specific gravity is 0.050 or greater or the lowest
cellspecificgravityislessthan1.225,chargethebat-
tery. Charge at the recommended rate and time giv-
en in Charging or until all c ells specific gravity is
1.225orgreaterwiththedifferenceinspecificgravity
betweenthehighest andlowestcell lessthan0.050.
If these charging conditions can not be met,replace
the battery.
3. Perform a high--discharge test with an adjustable
load tester.
Thisisoneofthemostreliablemeansoftestingabattery
asitsimulatesthecold--crankingtest.Acommercialbat-
tery load tester is required to perform this test.
CAUTION
Followthemanufacturer’sinstructionswhenus-
ing a battery tester.
A. Check the voltage across the battery terminals
prior to testing the battery. If the voltage is less than
12.4 VDC,charge thebattery before continuingwith
load testing procedure.
B. If the battery has recently been charged, apply a
150 amp load for 15 seconds to remove the surface
charge. Use a battery load tester following the
manufacturer’s instructions.
C. Makesurebatteryterminalsarefreeofcorrosion.
D. Measure the temperature of the center cell.
E. Connectabattery loadtestertothebatterytermi-
nals following the manufacturer’s instructions.
Connectadigitalmultimetertothe batteryterminals.
F. Applyatestloadof325amps(onehalfthebattery
cold cranking amp rating) for 15 seconds.
G. Take a battery voltage reading at 15 seconds,
then remove the load.
H. Using the table below, determine the minimum
voltage for the cell temperature reading:
Minimum
Voltage
Battery Electrolyte
Temperature
9.6 70
o
F (and up) 21.1
o
C (and up)
9.5 60
o
F 15.6
o
C
9.4 50
o
F 10.0
o
C
9.3 40
o
F 4.4
o
C
9.1 30
o
F -- 1.1
o
C
8.9 20
o
F -- 6.7
o
C
8.7 10
o
F --12.2
o
C
8.5 0
o
F --17.8
o
C
I. If the test voltage is below the minimum, replace
the battery. If thetest voltageis at orabove themini-
mum, return the battery to service.
Electrical
System