SR500L  – SR750L  Series

500W & 750W Standby Float Charger for Lead Acid Batteries

The SRL models are designed for use as a precision AC to DC power supply, or a float charger for lead acid batteries. Note that for float charging the output voltage must be set to approximately 15% above the nominal battery voltage. The SRL series can have an optional ethernet, RS485 or RS232 communications port fitted.


  • 12V, 24V, 30V  36V  & 48V output voltage models have been replaced by SR500HL & SR750HL
  • Industrial quality AC/DC power supply
  • Standalone – benchtop or fixed mounting
  • Front panel controls & indication
  • Suitable for float charging of lead-acid batteries
  • Suitable for parallel operation
  • Conservative design for long life
  • Precise voltage and current control

Optional Features

  • American Input Voltage 110VAC ( 88 – 135VAC)
  • Communication Port ( RS232 ASCII – SR485 – MODBUS RTU  – SNMP , webpages)
  • Mounting: 19″ Rack Mount  with V/I meter available, Wall mount
  • N+1 redundancy
  • Boost Charger
  • Optional temperature compensation for charging
  • Optional relay alarm outputs
  • Optional DC input
DC Power Supply Manufactures - DC UPS


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

Accessories Supplied

  • Mounting feet together with screws
  • AC power cord 1.5m with IEC320 socket and NZ/Aust plug
  • Mating screw-terminal plug for alarm outputs
  • Crimp lugs for stud terminal versions
  • DC screw terminal plug-in connector for ‘X’ version


 ModelOutput (V) Output (A)Power (W)
SR500L1213.836.2 (41.6 @ 12V)500
SR750L1213.836.2 (41.6 @ 12V)750

12V, 24V, 30V  36V  & 48V output voltage models have been replaced by SR500HL & SR750HL


Input180V – 264V ( 88V-132VAC option)
FusingInternal AC input fuse
Overcurrent protectionConstant current limit under overload and short circuit conditions (except DC input versions which have primary current limit)
Isolation1KV DC input – output / earth
Efficiency> 85%
Hold-up time15 – 20 ms without batery
AlarmsMains fail (or PSU in standby mode)
DC low (Battery low or PSU low) – set at 92% of nominal voltage.
DC high
Alarm  relay contactsC – NO – NC changeover rated 1A /50V DC, 32VAC
AC Input ConnectorIEC320 inlet socket
CommsChoice of RS485 ,RS232, Ethernet
ProtocolsSNMP v1 or Modbus (external converter)
Dimensions146.5 W x 62 H  x 177 D mm (SR100L) , 150W x 61H x 242D (SR250L)
Weight0.94Kg (SR100L) , 1.7Kg(SR250L)
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
CoolingFan cooled
EmiTo CISPR 22 / EN55022 class A
SafetyTo IEC950 / EN60950 / AS/NZS3260

IE ASCII to Modbus RTU converter

  • +PROTOCONMB protocol converter is designed to be used with No-BreakTM DC power supplies, with single battery output, for example, SR100i or SR250i with RS485 communication port. It enables the
    user to monitor and control in real time various power supply parameters using Modbus RTU protocol via the RS485 output port or the RS232 programming port.

IE ASCII to Modbus RTU converter +PROTOCONMB


  • The +PROTOCONMB-OE converter, in addition to the above, enables the user to monitor and control the power supply via Modbus TCP and HTTP over Ethernet. For further information on this version please refer to the +PROTOCONMB-x-OE data sheet.

IE ASCII to Modbus RTU converter +PROTOCONMB-OE


Custom Solutions


Custom Standalone Systems using SR500L and SR750L

Model NumberDescription
CSR106Custom SR750L24TFSL-LAN+ with 5m Tempco
CSR130Custom SR750L48TFXL-LAN+ (quotation only)
CSR147Custom SR750L48FX 60Vdc 750W no front
CSR153Custom SR750L24TFSL charger 24V 750W
CSR155Custom SR500L12TFSL Float Charger 13.8V
CSR161Custom SR500L24FSL, PSU set to 29Vdc 500W
CSR162Custom SR750L36TFSL 36V 750W Charger with
CSR164Custom SR750L30TFSL 30V 750W Charger with 5m Tempco
CSR167Custom SR750L24TFSL Charger with 5m Tempco and Connector
CSR175Custom SR750L24TFSL with Conformal Coating
CSR177Custom SR750L24TFSL-LAN+ w/5m tempco & connector
CSR183Custom SR500L24FSL 500W 24V PSU/ Charger, front adjustment pot.
CSR193Custom SR500L24TFXL-LAN+ with Conformal Coating and Tempco Connector
CSR194Custom SR750L30TFSL 30V 750W Charger with 5m Tempco
CSR195Custom SR750L24TFSL Charger 24V 750W 5m Tempco
CSR209Custom SR500L24FXL 500W 24V PSU/ Charger, front adjustment pot.
CSR213Custom SR500L12FSH, 110/12VDC DC/DC Converter with Fan Filters
CSR214Custom SR750L24FXH, MAX CURRENT 23A, 110/24VDC DC/DC Converter with Fan Filters,
CSR216Custom SR500L24FXH, 110/24VDC DC/DC Converter with Fan Filters
CSR217Custom SR750L92TFXL w/internal shunt meter, Charger 108V 750W
CSR224Custom SR750L24FSL w/front adj. pot. PSU/Charger 24V 750W alarms
CSR226Custom SR750L48TFSL with Fan Filter


Custom 19″ Rack Mount Systems using SR500L and SR750L

Model NumberDescription
CSB1542U 750W 24V Charger SR750L24TFSL w/meter,
CSB1742U 750W 27.3V Charger, SR750L24TFSL
CSB2202U 750W 48VDC Charger SR750L48TFSL diode
CSB2212U 500W 110Vdc Charger SR500L92FXL
CSB2242U 750W 36VDC Float Charger SR750L36TFSL
CSB2442U 750W48V Charger SR750L48TFSL
CSB2562U 750W Charger SR750L48TFSL, meter
CSB2572U 500W 24V PSU,  incl. SR500L24FSL,
CSB2602U 750W 34.13V Charger SR750L30TFSL-01
CSB2642U 750W 24V Charger SR750L24TFSL, tempco,
CSB2672U 500W 29V PSU SR500L24FSL with Anderson Connectors
CSB2692U 500W 110VDC Charger SR500L92TFXL
CSB3022U 750W 36V Charger SR750L36TFSL with V/I Meter, Diode and Alarms
CSB3032U 750W 36V Charger SR750L36TFSL-01(CSR162)
CSB3062U 750W 24V Charger SR750L24TFSL w/meter,
CSB3102U 500W 110V PSU, SR500L92FXL w/diode
CSB3322U 750W 124VDC Float Charger SR750L92TFXL (quoted to ABB DO52317)
CSB3372U 750W 110V Charger SR750L92TFXL
CSB3412U 750W 24VDC Charger SR750L24TFSL, Meter, Diode with Conformal Coating
CSB3522U 750W 24V Charger SR750L24TFSL-LT
CSB3662U 750W 110V SR750L92TFXL, diode, meter, 2 x 2P Anderson conectors
CSB3672U 750W 24V SR750L24TFSL-LAN+, diode, meter, 2 x 2P Anderson conectors
CSB3692U 750W 110VDC Charger SR750L92TFXL
CSB3722U 500W 48V PSU SR500L48FXL, meter
CSB3732U 500W 48V PSU SR500L48FXL-LAN+, meter, SNMP
CSB3812U 750W 110V Charger with diode (SR750L92TFSL, +P50HV)
CSB3822U 750W 12V SR750L12FSL-LAN+ (proposed for Helios/Simoco 15/03/2019)
CSB3992U 750W 34.13V Charger SR750L30TFSL-01 with conformal coating,
CSB4042U 750W 12V Charger SR750L12TFSL w/meter, rear connectors
CSB4102U 750W 120V Charger SR750L93TFXL, meter, diode
CSB4442U 750W 30V Charger SR750L30TFSL-485 incl.
CSB4632U 500W 24VDC Float charger, meter and MODBUS (SR500L24TFXL-485)
CSB4732U 500W 24V 1+1, CSR209 (SR500L24FXL with front adj. pot), diode
CSB4942U 750W 24VDC Float Charger, meter and MODBUS (SR750L24TFSL485)
CSB4962U 750W 12V PSU/Charger, meter, studs SR750L12TFSL
CSB5052U 750W 36VDC Float Charger with VI Meter (SR750L36TFXL)
CSB5132U 750W 108V Charger SR750L92TFXL, 2U subrack, no rear panel
CSB5172U 750W 24V Charger SR750L24TFSL, meter, tempco, battery LVD, Anderson connectors
CSB5212U 500W 24V Charger SR500L24TFSL, Anderson conns.
CSB5252U 500W 24V  Charger SR500L24FSL front adj.pot (CSR183), diode
CSB5282U 750W 24VDC Charger SR750L24TFSL, front adj. pot,


Custom Floor Mount Cabinet Systems using SR500L and SR750L

Model NumberDescription
CAB3972U 500W 48VDC Charger (SR500L48TFXL)
CAB364Sys 6U 500W 24VDC Charger SR500L24FSL
CAB365/512U 500W 24VDC Redundant Charger SR500L24FXL (x2)
CAB1164SEC-SR 500W 36VDC Wall Mount Float Charger, SR500L36TFSL
CAB1163SEC-SR 500W 24VDC Wall Mount Float Charger, SR500L24TFSL
CAB11326U 500W 24V Charger SR500L24FSL
CAB104012U 500W 24VDC Redundant Charger SR500L24FXL (x2)
CAB101133U 750W 24V (1+1) SR750L24TFSL-LAN+, diode
CAB1067SEC-SR 750W 24VDC Wall Mount Float, CSR195 (SR750L24TFSL) meter, alarm card
CAB113124U 750W 24V Dual Charger SR750L24FSL
CAB114138U 2.25kW 110V PSU (SR750L +750W 24V Charger (SR750C)
CAB203Sys 2U(x2) SR750L30 with tempco, meter,diode, Alarms
CAB2592U 750W 124V Charger, SR750L92TFXL Alarms,Meter,Tempco
CAB259/12U 750W 124VDC, Charger SR750L92TFXL
CAB332Snaptec DO31244 SR750L24TFSL-LAN+ RkMt
CAB381SEC-SR with SR750L48FSL, 3 x MCBs, alarm card
CAB757SEC-SR 750W 24VDC SR750L24FSL, w/ diode, meter
CAB758SEC-SR 750W 24VDC SR750L24FSL, w/ diode, meter,
CAB89318U 750W(x2) 12V Chargers SR750L12TFSL with meters
CAB91133U 750W 120V SR750L93TFXL

SR500L model has been replaced by SR500HL . If you happen to require one of the models listed above, the system will have the new SR500HL model, which is a upgraded version of the SR500L.


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