ALM
®
12V7 s-Series User’s Guide
Chapter 5: Operation and System Design Considerations
406014-02EN, Rev. 05
© 2016 NEC Energy Solutions, Inc. All rights reserved.
Page 29 of 49
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provides curved graphs of the ALM 12V7s base power model and ALM 12V7s HP
high power model enforced current limits.
ALM 12V7s Current Limit Profile (Base Power)
ALM 12V7s HP Current Limit Profile (High Power)
Figure 5 Current Limit Profiles for the ALM 12V7s and ALM 12V7s HP Models
Over Discharge Protection Under Voltage Protection (UVP)
As the ALM 12V7 s-Series battery nears 0% State of Charge (SOC), the terminal voltage
begins to drop rapidly. The battery is considered fully discharged when one of its internal cell
voltages falls to 2.0 volts or the battery’s terminal voltage is in the range of 8.0 volts to
11 volts.
The ALM 12V7 s-Series is designed to enter an Under Voltage Protection (UVP) state if any
cell drops below 2 volts. In the UVP state, the ALM 12V7 s-Series battery will disconnect its
terminals causing the output voltage to drop to 0 volts. Slight differences in the cells’ state of
charges lead to differences between the cell voltages, especially at low states of charge. In
such a case, one cell may activate the UVP protection before the others do. When this
happens the voltage measured at the battery terminals will be higher than 8 volts.
page 30, shows the voltage at which a battery could enter UVP and open the terminals. UVP
is disabled and the terminals are closed once the battery is connected to an active charge
source and/or the lowest cell voltage returns to 2.5 volts or higher.
