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.


  • 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:  Rack Mount 19″ with V/I meter available, Wall mount
  • N+1 redundancy
  • Boost Charger
  • Optional temperature compensation for charging
  • Optional relay alarm outputs
  • Optional DC input


  • 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


 Model Output (V) Output (A) Power (W)
SR500L12 13.8 36.2 (41.6 @ 12V) 500
SR500L24 24 20.8 500
SR500L30 30 16.6 500
SR500L36 36 13.8 500
SR500L48 48 10.4 500
SR500L60 60 8.3 500
SR500L91 96 5.2 500
SR500L92 108 4.6 500
SR500L93 120 4.1 500
SR750L12 13.8 36.2 (41.6 @ 12V) 750
SR750LA24 24 20.8 750
SR750L30 30 16.6 750
SR750L36 36 13.8 750
SR750L48 48 10.4 750
SR750L91 96 5.2 750
SR750L92 108 4.6 750
SR750L93 120 4.1 750


Input 180V – 264V ( 88V-132VAC option)
Frecuency 45-65Hz
Fusing Internal AC input fuse
Overcurrent protection Constant current limit under overload and short circuit conditions (except DC input versions which have primary current limit)
Isolation 1KV DC input – output / earth
Efficiency > 85%
Hold-up time 15 – 20 ms without batery
Alarms Mains fail (or PSU in standby mode)
DC low (Battery low or PSU low) – set at 92% of nominal voltage.
DC high
Alarm  relay contacts C – NO – NC changeover rated 1A /50V DC, 32VAC
AC Input Connector IEC320 inlet socket
Comms Choice of RS485 ,RS232, Ethernet
Protocols SNMP v1 or Modbus (external converter)
Dimensions 146.5 W x 62 H  x 177 D mm (SR100L) , 150W x 61H x 242D (SR250L)
Weight 0.94Kg (SR100L) , 1.7Kg(SR250L)
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
Cooling Fan cooled
Emi To CISPR 22 / EN55022 class A
Safety To IEC950 / EN60950 / AS/NZS3260

Custom Solutions

CAB365 Wall Mount Battery Charger 7

CAB365 is a 750W 24VDC redundant battery charging system in a 12U 19-inch wall mount cabinet. The system comprises of two SR750L24FSL in 2U 19” sub-racks with a 50A decoupling diode, Digital V/I meter and Alarm card and LVD for protection. The system is set to provide 27.2VDC at the output of the decoupling diodes to float charge the batteries and provide the load. The output voltages of the SR750L24FSL’s are front adjustable with a variable potentiometer on the front of the chargers.

The AC input of a charger is protected with a 6A AC Input MCB and the output of the 2U chargers is protected with 32A 2P MCB. A P50 diode in the positive output of the chargers ensures redundancy configuration of the chargers in the system. The system output is monitored with a Digital V/I meter and Alarm Card and a LVD controlled by the Alarm Card disconnect the load if the battery voltage drops to 22VDC. A 63A load isolator ensures isolation of the load from the chargers and battery. A 63A single pole battery breaker protects the battery and the system is also equipped with an Emergency 24VDC Input connection on WDU10 terminals which is protected with a 63A single pole Emergency Input MCB.

Features of CAB365 include

  •  750W 24VDC Redundant charger in a 12U 19” wall mount cabinet
  • Charger output voltage front adjustable on chargers
  • 2 x 32A 2P Charger Output Breakers
  • 63A 1P Battery Breaker
  • Emergency 24VDC Input with 63A 1P Breaker
  • 63A 1P Load Isolator
  • Digital V/I meter
  • Low Voltage Disconnect set at 22VDC
  • Various Charger and System alarms
  • DIN rail Alarm terminals with links

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