SR100i – SR250i – NO – Break DC UPS 100W – 250W

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)


Input180V – 264VAC
Input Optional88V – 132VAC  (internal link select)
88-135VDC (specify at time of order)
FusingInternal AC input fuse
Overcurrent protectionConstant current limit under overload and short circuit conditions
Isolation1KV DC input – output / earth
Efficiency> 85%
Output power100W – 250 W
Output voltages13.8, 27.6, 34.5, 41.4, 55.2VDC
Voltage adj. range85 – 115% of Vout
Temperature  CompensationTemperature sensor on 1.7m lead with adhesive pad:  -4mV / °C / cell ±10%
Current limitPSU:  100% rated current  – Battery:  25-100% PSU current
Hold-up time15 – 20 ms without batery
Thermal ProtectionYes, self-resetting
Operating  temperature0 – 50 °C ambient at full load.De-rate linearly >50 °C to no load @ 70 °C
Storage temperature-10 to 85 °C ambient
Humidity0 – 95% relative humidity non-condensing
AC Input ConnectorIEC320 inlet socket
Battery charge current limitSee Model Table for default settings – may be increased to PSU rated current
Reverse polarity protectionBattery reverse connection will open internal fuse (and produce alarm)
Battery monitoringDetects for presence of battery on start up, then every 60 minutes when charge current < 200mA
Battery circuit protectionElectronic circuit breaker (ECB) operates under the following conditions:
– low battery voltsbattery 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 indicationGreen:  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 contactsC – 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 ModeTurns off DC output of PSU & allows load to run off battery
Dimensions147W x 177D x 62H mm , 242W x 150D x 61H mm (excluding mounting feet and connections)
Weight0.95 Kg , 1.7Kg
AC Input ConnectorIEC320 inlet socket