NEC ALM 12V7 s-Series, Руководство пользователя

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406014-02EN, Rev. 05 © 2016 NEC Energy Solutions, Inc. All rights reserved. Page 40 of 49
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ALM
®
12V7 s-Series User’s Guide Chapter 5: Operation and System Design Considerations
Voltage drop in the ALM 12V7 s-Series is an inverse function of the ALM 12V7 s-Series
battery’s internal temperature. As the internal temperature of the ALM 12V7 s-Series drops,
the impedance rises leading to an increased voltage drop. It is important to consider the
resulting performance impacts when designing a product for cold conditions.
Figure 9 shows
impacts of temperature on 50W constant power discharge.
Figure 9 ALM 12V7 s-Series Typical 50W Constant Power Discharge Behavior
The ALM 12V7 s-Series battery’s End of Discharge (EOD) terminal voltage is a function of the
core cells, any cell-to-cell variations and series impedance of the internal power pathway.
These elements are impacted by discharge rate and temperature. The battery’s protection
circuitry will stop discharge when any cell voltage drops below 2.0 volts.
Cell‐to‐cell variation has the largest impact on the expected EOD terminal voltage. Cells vary
in performance in a variety of ways based on normal manufacturing.
Applications that use a low battery voltage threshold value (LVCO, LVLD, LVBD, etc.) to
initiate actions such as disconnecting the load or initiating a charge cycle should adhere to
the battery terminal voltages shown in the discharge performance curves in
Figure 7 ,
Figure 8 , and Figure 9 . Depending on the discharge rate, temperature, and other factors in
the application, a different voltage trigger value based on the appropriate discharge curve
may be needed, compared to lead-acid or other battery chemistries. Otherwise, undesired
behavior of the battery application may occur such as the unexpected loss of voltage if the
ALM 12V7 s-Series battery enters UVP state, or taking action too soon such as disconnecting
the load while significant energy still remains in the battery.