BATTERIES: ELECTRIC VEHICLES
Battery Testing
25
4.
When the float rises off the bottom, adjust the electrolyte level so that the float rides free of the bottom but does
not strike the top of the glass tube. Remove the hydrometer from the cell and release the pressure from the bulb.
5.
Hold the hydrometer vertically, ensuring that the float is not touching the sides of the barrel. Hold the hydrometer
at eye level and read the scale at the level of electrolyte
.
6.
Record the reading and return the electrolyte to the cell from which it was taken. Replace vent cap.
7.
Repeat steps 2 through 6 on all cells.
Hydrometer Calibration
Most hydrometers are calibrated to read correctly at 80 °F (26.7 °C). The readings obtained as described above must
be corrected for temperature. For each 10 °F (5.6 °C) above 80 °F (26.7 °C), add 0.004 to the reading. For each 10 °F
(5.6 °C) below 80 °F (26.7 °C), subtract 0.004 from the reading.
4 0
2 0
6 0
8 0
13 00
1.250
1.280
View at eye level.
717
Figure 25-4
Hydrometer
Interpreting the Results of the Hydrometer Test
The approximate state of charge can be determined from the following table:
SPECIFIC GRAVITY (TEMPERATURE CORRECTED)
APPROXIMATE
STATE OF CHARGE
1.250-1.280
100%
1.220-1.240
75%
1.190-1.210
50%
1.160-1.180
25%
If the difference between the cells is 0.020 or more, the low cell should be suspected. It may require a catch-up
charge or it may be a weak cell. When the variations between cells reach 0.050 or more, the battery with the low
cell should be replaced.
2007-2009 Turf 252, Carryall 252 and XRT 900 Maintenance and Service Manual
Page 25-9
