Cellwatch Frontier System Installation & User Manual
Section II – User Guide-88
Data Interpretation
Proper use of the battery monitoring system is critical to monitoring battery health. If the Frontier
system is not monitored regularly or connected to proper alert management systems, users will not
know of potential issues exposing their battery system to risks.
Voltage Alarms
Voltage alarm limits will vary with the chemistry of the battery. Always refer to manufacturer’s
specifications for voltage alarms.
Individual cell voltage alarms
Individual cell voltage alarms should be based on normal float conditions and by following battery
manufacturer recommendations. This should not be confused with equalization charge alarms.
String voltage alarms
String voltage can be used as the first step in preventing thermal runaway and ensuring the DC charger
is configured correctly. The low string voltage alarm limit is often calculated by multiplying the low cell
voltage alarm limit by the total number of monitored cells. Likewise, the high string voltage alarm limit is
found by multiplying the high cell voltage alarm limit by the total number of monitored cells. Verify with
the battery manufacturer what the recommended string voltage alarm limits should be set to.
Example: 2.21V (low cell voltage alarm) * 30 cells = 66.3V (low string voltage alarm)
Temperature Alarms
Temperature will vary depending on airflows around the battery string and/or the battery room.
Allowances for fluctuations in the environment should be considered. Most battery manufacturers
recommend electrolyte temperatures of 77°F or 25°C. Increasing temperatures can have detrimental
effects on the life of the cell but will increase available power. Decreasing temperatures can have
detrimental effects on the power capabilities of the cell, but typically will increase the lifespan of the
cell.
Ohmic Alarms
The ohmic value measurement consists of both a physical resistance and a chemical resistance. Thus,
ohmic value can change based on torque or changes in the conductive path of the plates (physical) or
due to changes in electrolyte or reactive area (chemical). While not directly linked to ampere hour
capacity (AH), increases in ohmic value often indicate a decrease in the ability for the cell to perform
during a discharge event.
Warning: It only takes one open cell to cause a string failure.
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