Reference Manual
All parameters are specified at 24V, 10A output load, 25°C ambient and after a 5 minutes run-in time unless noted otherwise.
It is assumed that the input power source can deliver a sufficient output current.
Rockwell Automation Publication 1606-RM036A-EN-P — April 2014 7
Bulletin 1606 Switched Mode Power Supplies
8. Battery Input
The DC-UPS requires one 12V VRLA battery to buer the 24V output.
Battery voltage nom. DC 12V Use one maintenance-free 12V VRLA lead acid battery or
one battery module which is listed in the Accessories
section.
9.0 – 15.0V Continuously allowed, except deep discharge protection
Battery voltage range
max. 35Vdc Absolute maximum voltage with no damage to the unit
typ. 7.4V Above this voltage level battery charging is possible.
Allowed battery sizes min. 3.9Ah
max. 40Ah
max. 100mOhm See individual battery datasheets for this value. Internal battery resistance
Battery charging method CC-CV Constant current, constant voltage mode
Battery charging current (CC-mode) nom. 1.5A Independent from battery size,
max. 1.7A Corresponding 24V input current see Fig. 8-2
End-of-charge-voltage (CV-mode) 13.4-13.9V Adjustable, see section 14.
Battery charging time typ. 5h *) For a 7Ah battery
typ. 17h *) For a 26Ah battery
Battery discharging current **) typ. 21A Buer mode, 10A output current, 11.5V on the battery
terminal of the DC-UPS, see
Fig. 8-1 for other parameters
typ. 0.3A Buer mode, 0A output current
max. 50μA At no input, buering had switched o, all LEDs are o
typ. 270mA At no input, buering had switched o, yellow LED
shows “buer time expired” (max. 15 minutes)
typ. 10.5V At 0A output current
Deep discharge protection ***)
typ. 9.0V At 10A output current
*) The charging time depends on the duration and load current of the last buer event. The numbers in the table represent a
fully discharged battery. A typical gure for a buer current of 10A is 3h 20 min (200 min) for a 7Ah battery.
**) The current between the battery and the DC-UPS is more than twice the output current. This is caused by boosting the 12V
battery voltage to a 24V level.
This high current requires large wire gauges and short cable length for the longest possible
buer time. The higher the resistance of the connection between the battery and the DC-UPS, the lower the voltage on the
battery terminals which increases the discharging current. See also section 25 for further installation instructions.
***) To ensure longest battery lifetime, the DC-UPS has a battery deep discharge protection feature included. The DC-UPS stops
buering when the voltage on the battery terminals of the DC-UPS falls below a certain value. The yellow LED will show
“buer time expired” for a period of 15 minutes after the unit stopped buering.
Fig. 8-1 Battery discharging current
vs. output current, typ.
Fig. 8-2 Required input current vs. input
voltage for battery charging
Battery Current
0
0
10
20
5
15
25
30A
2.5 7.5 10 15A12.55
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Voltage on
battery terminal
of the DC-UPS:
A:
10.5V
B:
11V
C:
12V
A B C
Input Current
0
23
0.5
1.0
0.25
0.75
1.25
1.5A
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24 25 26 28V
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