406014-02EN, Rev. 05
© 2016 NEC Energy Solutions, Inc. All rights reserved.
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ALM
®
12V7 s-Series User’s Guide
Chapter 5: Operation and System Design Considerations
Charging Multiple Batteries
When charging multiple batteries, maximum charge current should not exceed 45 A for arrays
of ALM 12V7 s-Series batteries connected in parallel and/or series configurations. The end-
of-charge voltage will depend on the system’s series and parallel configuration.
Charging Batteries in Series
To determine the maximum end-of-charge voltage to apply for battery systems configured in
series, multiply the number of batteries connected in series by the maximum charge voltage
of a single battery (14.4 V), as shown in
.
Eq. 1 (Number of Series Connected ALM 12V7 s-Series Batteries) x (14.4V) = Max Charge Voltage, Battery
System.
shows Recommended Float and Maximum Charge voltages. Charger voltages
exceeding the Maximum up to 60.0 volts will not damage an ALM 12V7 s-Series battery, but
the battery may not operate due to over voltage protection. When the battery is in the normal
state, the charger voltage should be less than or equal to the Maximum Charge Voltage.
WARNING
Applying charger voltages in excess of 60.0 V could damage the charge and
discharge control circuitry, creating a safety hazard, and will void the warranty.
Charging Batteries in Parallel
The maximum charge current for any parallel array of batteries is 45 A.
Table 15 Supported Float and Maximum Charge Voltages
Series Configuration
Recommended Float Charge Voltage (V)
Maximum Charge Voltage (V)
1s
13.6 to 14.4
16
2s
27.25 to 28.8
32
3s
40.8 to 43.2
48
4s
54.5 to 57.6
60
