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Rev.12/31/97
and follow their recommendations.
5.11 TESTING
5.11 TESTING
A. Upon Installation
A. Upon Installation
Acceptance capacity testing should be performed within 1 week after the
battery has reached equilibrium in charge and temperature. Operating
temperature of the battery will greatly affect the available capacity, and
manufacturer's data must be consulted for correction factors. Maintain
accurate records of tests, including all equipment used and test results.
These records can be used as baseline for later comparisons.
battery has reached equilibrium in charge and temperature. Operating
temperature of the battery will greatly affect the available capacity, and
manufacturer's data must be consulted for correction factors. Maintain
accurate records of tests, including all equipment used and test results.
These records can be used as baseline for later comparisons.
1. Conduct the test only after a connection resistance test has been
performed as in 5.9 above.
2. Install an accurate ammeter, voltmeter, and temperature
instrumentation, and provide an accurate stopwatch or other means to
indicate elapsed time. Minimum test time should be at least 1 hour.
More time is recommended for critical applications and test accuracy.
3. Provide a variable load resistance so that constant current can be
maintained equal to the rating of the battery for the selected test time.
4. Disconnect the charger.
5. Read and record individual cell/module voltages and the battery terminal
voltage. The readings should be taken after applying the load at the
beginning of the test. Repeat the readings at specified intervals and plan
the test time long enough in advance to provide a minimum of five sets of
readings.
beginning of the test. Repeat the readings at specified intervals and plan
the test time long enough in advance to provide a minimum of five sets of
readings.
Caution:
Take individual cell voltage readings between
respective terminals of like polarity ( positive to positive) so the voltage
drop of the intercell connectors will be included. See figure 10 for probe
placement.
drop of the intercell connectors will be included. See figure 10 for probe
placement.
6. If an individual cell/module is approaching reversal of its polarity (zero
volts) or a module voltage is 2 volts or more lower than the others, but
the overall terminal voltage has not reached its test limit, bypass the
cell/module and continue the test. Perform the bypass connection away
from the cell/module to avoid arcing. A new minimum voltage based on
the remaining cells should be established for the remainder of the test
(1.75 times the number of remaining cells).
the overall terminal voltage has not reached its test limit, bypass the
cell/module and continue the test. Perform the bypass connection away
from the cell/module to avoid arcing. A new minimum voltage based on
the remaining cells should be established for the remainder of the test
(1.75 times the number of remaining cells).
Consult the manufacturer and prepare to bypass cells in advance. The
possibility of weak cells is high, especially as the battery ages.
possibility of weak cells is high, especially as the battery ages.
7. Maintain the discharge rate until the battery terminal voltage decreases
to a value equal to the manufacturer's specified minimum voltage per cell
(usually 1.75 volts) times the number of cells.
(usually 1.75 volts) times the number of cells.