Lucent Technologies 2VR250E, Руководство по эксплуатации продукта

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Lucent Technologies Enhanced VR Series Batteries
Issue 5 December 1998 Operation 7 - 7
Discharge
Capacity Test
Since the Enhanced VR batteries are long-life batteries, this test
is not required as a routine maintenance procedure. However, a
discharge test is the best way to determine if sufficient reserve
power is available.
The discharge capacity test should be run directly off float
charge. Modules to be tested should be on float for at least one
month without a power failure exceeding 30 minutes.
There are several different methods that can be used in testing
the capacity of the string. In general, the more definitive the test,
the longer and more difficult it is to perform.
If it is determined that a discharge test should be part of the
maintenance program, carry out the test consistently from site to
site and interval to interval. This way, comparisons and trends
will be easier to evaluate. In selecting a test, the choices are as
follows:
• single battery module or string
• partial or full discharge
• constant or variable load
The easiest test to run is to shut off the ac power and let the plant
load discharge the batteries until 20% to 50% of the capacity has
been removed. The disadvantage of this type of test is that the
current may not be constant throughout the discharge, from
interval to interval, or from site to site. You can overcome this
disadvantage by adding an external load to the bus. You can
adjust this load throughout the discharge to maintain a constant
current.
In light of the above, a one-hour augmented plant load discharge
is the preferred routine maintenance test. The one-hour
discharge rate to 1.90 volts is a reasonable value since it will
leave approximately 60% reserve at a lower rate. You should
only perform a single-string, off-line, five-hour rate to 1.75 volt
discharge test whenever you need a very accurate appraisal of
the capacity. Do not use it on a routine basis. To carry out a
discharge test properly, measure and record the time, current,
module voltages, ambient temperature, and battery temperature
at the start and periodically throughout the test. To achieve
reasonable accuracy, the thermometer should be accurate to
within 2 degrees Fahrenheit. Measure the current and time to an
accuracy of 1% and the module voltage to the nearest millivolt.