100W DC UPS   No – Break ™ DC Uninterruptible Power Supply TECHNOLOGY

The New SR100Hi 100 W power supply is designed to provide DC power to lead-acid batteries for critical backup applications.All the functionality and durability has been retained with a more modern and easier to understand range of products being developed.Form factor and connectivity remains the same, so they will fit into the slots occupied by the old range – the legend continues!

No-Break ™ DC UPS systems maximise the integrity of standby battery installations, whilst optimising the life and availability of back up batteries.  They are available with Serial and Ethernet Communications options.

The No-Break ™ system is the ideal solution for:

  • Critical systems of 100W to 250W (and above using parallel operation)
  • Applications requiring continuous on-line monitoring of battery and charger status
  • Providing cost-effective management of your battery system investment

Other features include:

  • Ability to view power supply data remotely
  • Automatic or manually initiated battery condition testing to ensure availability of standby power
  • The battery condition test feature of the No-Break ™ DC system determines the condition of the back-up batteries and will provide an early warning of potential failure. This gives plant operators enough warning to replace the faulty batteries before they are required, like in the event of a mains power failure. Battery condition tests are mandatory on some fire alarm systems and are now commonly specified by consultants for critical industrial systems.


  • Security – Access Control
  • Industrial Processes Switching Protection
  • Radio Repeaters – Remote Sites
  • WiFi Broadband Transmitters

Points Of Difference

  • Separate outputs for load and battery.
  • Battery detection—regular battery presence and battery circuit integrity checks.
  • Battery deep discharge protection.
  • Power loss & battery system alarms
  • No transition switching to backup battery
  • Rugged design and construction for long life and challenging environments

Optional Features

  • American Input Voltage 110 VAC ( 88 – 135 VAC)
  • Communication Port ( RS232 ASCII – SR485 – MODBUS RTU – SNMP, webpages)
  • Digital Input/Outputs: Customizable 3 digital inputs & 1 digital output.
  • Battery Condition Test: Option auto test enabled on start-up
  • Mounting: DIN rail, 19″ Rack Mount  with V/I meter available, Wall mount
  • N+1 redundancy
  • Boost Charger
  • Conformal Coating for harsh environments

SR100Hi - DC UPS - Power Supply Battery Charger 100 W remote sites


DC  Output
 Model Output (V) PSU Rated  (A) Charge Limit (A)* Recomm. Load  (A) Peak load on power fail (A)
SR100Hi12 13.8 7.5 7.5 6 11
SR100Hi24 27.6 3.7 3.7 3 5.5
SR100Hi30 34.5 2.9 2.9 2.3 4.3
SR100Hi36 41.4 2.4 2.4 1.9 3.6
SR100Hi48 55.2 1.9 1.9 1.5 2.8


Output power 100W
Input Voltage 180V – 264VAC 45-65Hz
Output Voltages 12V, 24V, 30V, 36V, 48 VDC
Voltage Adj. Range 85% – 105% of Vout
Frequency 45-65Hz
Overcurrent protection Constant current limit under overload and short circuit conditions
Isolation Input – earth – 2.5KVdc
Output – earth – 500Vdc
Efficiency > 85%
Operating temperature -20  to 50 °C ambient at full load
Humidity 0 – 95% relative humidity non – condensing
Cooling Natural convection


Optional Input Voltage 88 – 132 VAC
Communication Port RS232 (ASCII)
Modbus RTU
SNMP, Webpages
Digital Inputs/Outputs Customizable 3 Digital Inputs and 1 Digital Output
Battery Condition Test (BCT) Option auto test enabled on start-up
Mounting DIN Rail
19”Rack Mount. Optional V/I meter for subrack: SR-Meter
N+1 Redundancy Using 2 chargers each with its own battery.
Boost Charger Customizable feature on request.

Modbus & SNMP Downloads

SR Series – Comms Downloads



  •  Why is Helios Power Solutions SR No-Break ; DC charger recommended by consultants for critical applications?

Our No-Break ™ DC chargers have been designed for industrial use and have over twenty years of proven reliable operations.  In addition, the chargers have many outstanding features such as fault alarms, LED fault alarm codes, battery detection, low voltage disconnect circuitry, automatic battery condition testing, communication options and can be connected to the battery permanently due to the precise temperature-compensated voltage control.

  • Why should we use a SR No-Break; as opposed to a normal float charger?

The No-Break ™ DC UPS  has many features which a normal float charger does not, these including:

    • Precise alarm indication for mains or DC faults
    • Overcurrent protection on the battery circuit
    • Battery presence checking
    • Temperature-compensated charging
    • Low voltage disconnect circuitry to prevent deep discharge of the battery
    • Independent charge current limit
    • Automatic battery condition testing
  • Why don’t you use a boost charge on the SR No-Break unit?

Normally it is not necessary to have a boost on the No-Break ™ unit, as the power is on the system continuously and it is not that critical to restoring 100% of charge rapidly, as in the case of cyclic applications.  A boost charge voltage may damage the equipment which is permanently connected to a standby system.

  • Can I use the SR No-Break DC UPS without a battery?

No, the No-Break ™DC UPS is designed to operate with a battery connected and instability may result if there is no battery connected.  If you wanted to do this then it is advisable to use a standard two-terminal DC power supply SR100HL

  • Why is the battery negative separate from the load negative in the SR No-Break DC UPS?

This is done to implement two of the features of the No-Break ™ UPS/charger.  There is an “electronic circuit breaker” fitted between the battery negative and load negative terminals to provide the battery overcurrent protection.  The separate battery circuit also allows for independent control of the charging current when required.

  • Can I connect the battery directly to the load terminals when using SR No-Break DC UPS?

No, it would nullify all the features of using the No-Break ™DC design and provide false alarm signals from the relays.  If you wanted to do this, then it is advisable to use a standard two-terminal float charger, with or without alarms.

  • When does the SR No-Break system disconnect to protect deep discharge of the battery?

At approximately 1.67 volts per 2V (nominal) cell, so for a 12V system the disconnect voltage is set at 10V.

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