DC UPS – No – Break ™ DC Uninterruptible Power Supply TECHNOLOGY 

Helios Power Solutions proprietary No-Break ™ DC UPS Technology represents a truly unique, comprehensive approach to providing uninterruptible and secure DC power when you need it.The system maximises the integrity of standby battery installations whilst optimising the life and availability of the backup batteries.

The No – Break ™ DC UPS intelligent system provides a vastly improved solution over the traditional methods of float charger plus battery. The battery is accurately charged with independent current limit and you cannot overload the charger or overheat the battery.

The No – Break ™ DC UPS highly efficient system is the ideal solution for:

  • Systems which require no transition from mains to battery backup
  • Applications having standing load with back up standby battery installed
  • Cost-effective management of your battery system investment
  • Mission Critical systems from 100W to 750W and above.

Critical factors in the lifetime and capacity of (lead-acid) batteries

  • Temperature compensation
  • Controlled charge current
  • Regular check up
  • Deep discharge protection

Unique additional features of the No – Break ™ DC UPS system

Battery Detection: Monitors integrity of battery circuit hourly (battery missing, open fuse/electronic breaker)

Battery Condition Test (0ption): Indicative test of battery autonomy at predetermined intervals (automated battery condition check, ideal for remote sites).

Configurable Software 

Adjustable Load 

Communications Interface Port: (Options RS485 , RS232 , Ethernet)


 Models  Output (V)  PSU Rated  (A) Recomm. Load  (A) Peak load on power fail (A)
SR100i12 13.8 7.5 6 11
SR100i24 27.6 3.7 3 5.5
SR100i30 34.5 2.9 2.3 4.3
SR100i36 41.4 2.4 1.9 3.6
SR100i48 55.2 1.9 1.5 2.8
SR250i12 13.8 9 12 27
SR250i24 27.6 9 5 13.5
SR250i30 34.5 7.2 3.7 10.8
SR250i36 41.4 6 3 9
SR250i48 55.2 4.5 2 6.7


Input 180V – 264VAC
Input Optional 88V – 132VAC  (internal link select)
88-135VDC (specify at time of order)
Frecuency 45-65Hz
Fusing Internal AC input fuse
Overcurrent protection Constant current limit under overload and short circuit conditions
Isolation 1KV DC input – output / earth
Efficiency > 85%
Output power 100W – 250 W
Output voltages 13.8, 27.6, 34.5, 41.4, 55.2VDC
Voltage adj. range 85 – 115% of Vout
Temperature  Compensation Temperature sensor on 1.7m lead with adhesive pad:  -4mV / °C / cell ±10%
Current limit PSU:  100% rated current  – Battery:  25-100% PSU current
Hold-up time 15 – 20 ms without batery
Thermal Protection Yes, self-resetting
Operating  temperature 0 – 50 °C ambient at full load.De-rate linearly >50 °C to no load @ 70 °C
Storage temperature -10 to 85 °C ambient
Humidity 0 – 95% relative humidity non-condensing
AC Input Connector IEC320 inlet socket
Battery charge current limit See Model Table for default settings – may be increased to PSU rated current
Reverse polarity protection Battery reverse connection will open internal fuse (and produce alarm)
Battery monitoring Detects for presence of battery on start up, then every 60 minutes when charge current < 200mA
Battery circuit protection Electronic circuit breaker (ECB) operates under the following conditions:
– low battery volts battery voltage drops to 1.67V/cell  – auto reset on power on
– overload < 300ms for I bat > 6 x I PSU rated , allows ~1.5x rated PSU current from battery without acting,
 – short circuit < 2ms, backed up by fuse
LED indication Green:  Power OK – Green: Battery OK
Alarms  – Power OK (Mains/PSU fail)
– Battery System OK –  alarms when battery voltage low (on mains fail) , battery missing, battery circuit wiring faulty, BCT fail (if enabled)
Alarm  relay contacts C – NO – NC full changeover rated 30VDC,2A /110VDC,0.3A/125VAC,0.5A
Battery condition test (BCT) Standard on SR100- 250i – 20mins/28days unless otherwise specified on ordering.
Standby Mode Turns off DC output of PSU & allows load to run off battery
Dimensions 147W x 177D x 62H mm , 242W x 150D x 61H mm (excluding mounting feet and connections)
Weight 0.95 Kg , 1.7Kg
AC Input Connector IEC320 inlet socket