Ezgo TXT Fleet Electric Owner's Manual page 52

MAINTENANCE
Read all of this manual to become thoroughly familiar with this vehicle. Pay particular attention to all Notices, Cautions, Warnings, and Dangers.
the electrolyte weighs 1.280 times the weight of the same volume of water. A fully charged battery will test at 1.275 -
1.280 while a discharged battery will read in the 1.140 range.
Do not perform a hydrometer test on a battery that has just been watered. The battery must go through at least one
charge and discharge cycle in order to permit the water to adequately mix with the electrolyte.
The temperature of the electrolyte is important since the hydrometer reading must be corrected to 80° F (27° C). High
quality hydrometers are equipped with an internal thermometer that will measure the temperature of the electrolyte and
will include a conversion scale to correct the float reading. It is important to recognize that the electrolyte temperature is
significantly different from the ambient temperature if the vehicle has been operated.
Using A Hydrometer
1. Draw electrolyte into the hydrometer several times to
permit the thermometer to adjust to the electrolyte
temperature and note the reading. Examine the color
of the electrolyte. A brown or gray coloration indi-
cates a problem 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
contacting the top or bottom of the cylinder.
3. Hold the hydrometer in a vertical position at eye level
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 indicates a specific gravity of 1.250 and the
electrolyte temperature is 90° F (32° C), add four
points (.004) to the 1.250 which gives a corrected
reading of 1.254. Similarly 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) indi-
cates 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 exhib-
iting 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.
44
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
10 -12 -.028
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