BATTERIES
Battery Testing
2008-2011 IQ Plus Electric Vehicle Maintenance and Service Supplement
Page 14-11
14
3. Squeeze the rubber bulb of the hydrometer and insert into the cell. Slowly release the bulb, drawing elec-
trolyte up into the glass tube of the hydrometer.
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 pres-
sure 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.
Interpreting the Results of the Hydrometer Test
The approximate state of charge can be determined from the following table:
Figure 14-6 Hydrometer
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%
4 0
2 0
6 0
8 0
13 00
1.250
1.280
VIEW AT
EYE LEVEL
