Stationary VRLA Batteries,
Installation and Operation Instructions
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10.1 TOTAL SYSTEM VOLTAGE AND CURRENT
The total battery voltage at the terminal posts (positive and negative) during float charge
is 2.25 VPC times the number of cells.
Example: 2.25 VPC X 60 cells = 135 Total Battery Voltage
Check and record this overall voltage every quarter. If a deviation in voltage greater
than +/- 1% is found, then check the charger and make necessary adjustments.
Also, check and record the input current to the batteries every quarter. Consult the
specific battery product data sheet for acceptable values.
10.2 INDIVIDUAL CELL VOLTAGES
Pilot cell voltages must be taken and recorded on a 6 month basis. All of the individual
cell voltages must be checked and recorded at least once per year.
Single Cell Voltage Tolerance is +0.2 or -0.1V as compared to the nominal voltage
of 2.25; this gives us a range of 2.15 to 2.45 volts
If the individual cell voltages are not within the allowable tolerances contact BAE USA or
your local representative for recommendations.
10.3 CELL TEMPERATURE
Cell temperatures must be measured and recorded off the negative battery post.
10.4 FLOAT CURRENT
If float current is used to determine state of charge, it is important that this value be
measured accurately. Float current of a fully charged cell under normal conditions is
typically 20 to 30 mA per 100 Ah of capacity therefore the measuring device used must
be capable of that level of accuracy.
10.5 CONNECTION RESISTANCE MAINTENANCE READINGS
It is very important that the procedure for taking connection resistance readings be
consistent for each periodic reading so as to detect upward changes that could be
caused by corrosion or loose connections. Variations in taking the readings will cause
discrepancies in the results. Increased resistance is a cause for concern and may
require corrective action.
Normal connection resistance varies with the cell size and connection type. The
following methods should be used to establish a connection resistance limit, which
should initiate corrective action prior to the next inspection:
•
Baseline values are established by measuring the connections after initial installation
or after cleaning the connections (see Section 6.4).
o
A 20% increase from an established baseline value for any connection type (i.e.,
inter-cell, inter-tier, inter-rack) serves as the criteria for initiating corrective action
prior to going to the next inspection.
•
Baseline average values are specific to each connection (inter-cell, inter-tier, or inter-
rack) and not an average of all connections.
