ALM
®
12V7 s-Series User’s Guide
406014-02EN, Rev. 05
© 2016 NEC Energy Solutions, Inc. All rights reserved.
Page 28 of 49
This document contains the proprietary information of NEC Energy Solutions, Inc. (“NECES”) and may not be modified,
reproduced, retransmitted or redistributed, either in whole or in part, for any reason without NECES’ prior written consent.
Chapter 5
Chapter 5: Operation and System Design Considerations
Operation and System Design Considerations
Integrated EverSafe™ Battery Protection
The ALM 12V7 s-Series EverSafe™ battery technology includes integrated protection
circuitry to prevent the battery from certain damaging use conditions. The battery’s circuitry
interrupts either charging or discharging current if the battery is in danger of exceeding upper
or lower limits to voltage, current, and temperature.
Transient Energy Limit
The ALM 12V7 s-Series design protects the battery from transients containing excess energy
of up to 46 Joules. Inductance inherent in the cabling used to connect to the battery can
store this transient energy and release it to the battery’s protection devices as the battery’s
protection mechanism engages, which introduces an open circuit. When this occurs, active
sources like power supplies and battery chargers can create large transient spikes. While the
product has been designed to handle a maximum inductance of 5 μH and tolerate
connections to most power supplies, the user is responsible for ensuring that the battery
does not experience over voltage surge energy in excess of 46 Joules when conduction is
interrupted. External energy absorption devices like capacitors or clamps can reduce the
overshoot or stress on the battery and may be required based on the application.
Over Current Protection
The ALM 12V7 s-Series batteries apply a time-based current limit profile that allows higher
level current pulses for short durations.
on page 29 shows the maximum amplitude
limits enforced over increasing time intervals for the ALM 12V7s base power model and the
ALM 12V7s HP high power model. These curves have a -2% / +15% tolerance. The
maximum amplitude limit of 240 A decreases over time until it reaches a steady state limit of
23 A for the ALM 12V7s and 45 A for the ALM 12V7s HP. These current limit profiles apply to
both charge and discharge operations.
NOTE
Charge sources exceeding the continuous current will charge the battery at a duty-cycle inversely
proportional to the charger’s current. Exceeding the 240 A peak current will result in NO charge.
