Bad Boy 640690-G, Owner'S Manual

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44
MAINTENANCE
Read all of SAFETY and this section before attempting any procedure. Pay particular attention to Notices, Cautions, Warnings and Dangers.
Owner’s Manual
To prevent battery explosion that could result in severe personal injury or death, never insert a
metal thermometer into a battery. Use a hydrometer with a built in thermometer that is designed
for testing batteries.
Specific gravity is the measurement of a liquid that is com-
pared to a baseline. The baseline is water which is assigned a
base number of 1.000. The concentration of sulfuric acid to
water in a new golf car battery is 1.280 which means that 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 thermome-
ter 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 sig-
nificantly 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 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 near-
ing 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 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) indicates a problem with the low reading cell(s).
Hydrometer Temperature Correction
°F °C
160 71
150 65
140 60
130 54
120 49
110 43
100 37
90 32
80 26
70 21
60 15
50 10
40 4
30 -1
20 -6
10 -12
+.032
+.028
+.024
+.020
+.016
+.012
+.008
+.004
0
-.004
-.008
-.012
-.016
-.020
-.024
-.028
+.030
+.026
+.022
+.018
+.014
+.010
+.006
+.002
-.002
-.006
-.010
-.014
-.018
-.022
-.026
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
ELECTROLYTE
TEMPERATURE