Cushman 626501 Owner's Manual page 60

MAINTENANCE
Read all of this manual to become thoroughly familiar with this vehicle. Pay particular attention to all Notices, Cautions, Warnings, and Dangers.
Using A Hydrometer
1. Draw electrolyte into the hydrometer several times to
permit the thermometer to adjust to the electrolyte tem-
perature and note the reading. Examine the color of the
electrolyte. A brown or gray coloration indicates a prob-
lem with the battery and is a sign that the battery is
nearing the end of its life.
2. Draw the minimum quantity of electrolyte into the
hydrometer to permit the float to float freely without con-
tacting the top or bottom of the cylinder.
3. Hold the hydrometer in a vertical position at eye level
5
and note the reading where the electrolyte meets the
scale on the float.
4. Add or subtract four points (.004) to the reading for
every 10° F (6° C) the electrolyte temperature is above
or below 80° F (27° C). Adjust the reading to conform
with the electrolyte temperature, e.g., if the reading indi-
cates a specific gravity of 1.250 and the electrolyte tem-
perature is 90° F (32° C), add four points (.004) to the
1.250 which gives a corrected reading of 1.254. Simi-
larly if the temperature was 70° F (21° C), subtract four
points (.004) from the 1.250 to give a corrected reading
of 1.246.
5. Test each cell and note the readings (corrected to 80° F
or 27° C). A variation of fifty points between any two cell
readings (example 1.250 - 1.200) indicates a problem
with the low reading cell(s).
As a battery ages the specific gravity of the electrolyte will
decrease at full charge. This is not a reason to replace the
battery providing all cells are within fifty points of each
other.
Since the hydrometer test is in response to a vehicle
exhibiting a performance problem, the vehicle should be
recharged and the test repeated. If the results indicate a
weak cell, the battery or batteries should be removed and
replaced with a good battery of the same brand, type and approximate age.
5 - 22
ELECTROLYTE
TEMPERATURE
°F °C
160 71
+.032
+.030
150 65
+.028
+.026
140 60
+.024
+.022
130 54
+.020
+.018
120 49 +.016
+.014
110 43
+.012
+.010
100 37
+.008
+.006
+.004
90 32
+.002
0
80 26
-.002
-.004
70 21
-.006
-.008
60 15
-.010
-.012
50 10
-.014
-.016
40 4
-.018
-.020
30 -1
-.022
-.024
20 -6
-.026
-.028
10 -12
Hydrometer Temperature Correction
EXAMPLE #1
ELECTROLYTE TEMPERATURE
Above 80 °F (27 °C)
AMBIENT TEMPERATURE
Above 80 °F (27 °C)
ELECTROLYTE TEMPERATURE
Above 90 °F (32 °C)
HYDROMETER READING 1.250
1.250 + .004 = 1.254
CORRECTED SPECIFIC GRAVITY
READING
EXAMPLE #2
ELECTROLYTE TEMPERATURE
Above 80 °F (27 °C)
AMBIENT TEMPERATURE
Above 80 °F (27 °C)
ELECTROLYTE TEMPERATURE
Above 70 °F (21 °C)
HYDROMETER READING 1.250
1.250 - .004 = 1.246
CORRECTED SPECIFIC GRAVITY
READING