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the proper electrolyte level and oil level before charging.
B.
B. Float Charge
Float Charge
Float voltage is normally maintained at 1.40 to 1.42 volts per cell to avoid
gassing. Gassing begins at about 1.47 volts, and charging at this level should
be avoided because water consumption becomes excessive. Excessive
voltage variations between cells may be caused by excessively low float
voltage, which causes the battery to become partially discharged. If so, the
charger voltage setting should be increased slightly to within the above
limits. The charger voltmeter should be checked against an accurate digital
voltmeter at least once a year (see 1.2B).
gassing. Gassing begins at about 1.47 volts, and charging at this level should
be avoided because water consumption becomes excessive. Excessive
voltage variations between cells may be caused by excessively low float
voltage, which causes the battery to become partially discharged. If so, the
charger voltage setting should be increased slightly to within the above
limits. The charger voltmeter should be checked against an accurate digital
voltmeter at least once a year (see 1.2B).
C. Equalizing Charge
C. Equalizing Charge
An equalizing charge should not be given unless the battery has been
discharged to less than 90-percent capacity. Smaller discharges are handled
discharged to less than 90-percent capacity. Smaller discharges are handled
by float charging. A fully discharged ni-cad battery in good condition can be
fully recharged in 4 to 10 hours. When an equalizing charge is necessary,
1.52 volts per cell may be used (1.40 volts on a 92-cell bank) if the charger
can provide the current. As the battery charges, current decreases and
voltage stabilizes at the pre-set charger voltage. The charge should be
continued until charging current has leveled off for two consecutive
readings, 30 minutes apart. During an equalizing charge, carefully monitor
electrolyte temperature; lower charging voltage immediately if 115EF is
1.52 volts per cell may be used (1.40 volts on a 92-cell bank) if the charger
can provide the current. As the battery charges, current decreases and
voltage stabilizes at the pre-set charger voltage. The charge should be
continued until charging current has leveled off for two consecutive
readings, 30 minutes apart. During an equalizing charge, carefully monitor
electrolyte temperature; lower charging voltage immediately if 115EF is
reached.
6.6 VOLTAGE READINGS
6.6 VOLTAGE READINGS
Voltage readings must be taken by an accurate digital voltmeter (see section
1.3).
1.3).
A. Each Shift
A. Each Shift
Check the voltmeter on the control panel to determine if the battery is being
charged at the proper voltage. Adjust the voltage if necessary.
charged at the proper voltage. Adjust the voltage if necessary.
B. When Taps Are Changed
B. When Taps Are Changed
When taps are changed on power or station-service transformers, check the
voltage on the control panel and adjust the charging voltage if necessary.
voltage on the control panel and adjust the charging voltage if necessary.
C. During Initial Charge
C. During Initial Charge
Just before terminating the initial or equalizing charge, measure and record
the voltage of each cell with an accurate digital voltmeter. Choose a pilot
cell from one with the lowest voltage for readings in the coming year.
Change this cell each year.
the voltage of each cell with an accurate digital voltmeter. Choose a pilot
cell from one with the lowest voltage for readings in the coming year.
Change this cell each year.