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FLEXmax Extreme

FLEXmax Extreme

Regular price
$1,525.50
Sale price
$1,525.50
Unit price
per 

Product Highlights

  • Environmentally-rated outdoor enclosure
  • Solid-state, passively cooled design for quiet operation
  • Sealed architecture for long-term reliability
  • Easily integrated AXS Card/Modbus/TCP interface
  • Remote battery voltage sense improves battery charging performance

OutBack created the de facto industry standard when the company introduced its MX60 design, the first multi-voltage MPPT (Maximum Power Point Tracking) charge controllers. Now OutBack follows up on its original breakthrough with another first: a sealed, outdoor-rated charge controller with unprecedented thermal management capabilities designed for the most extreme environmental conditions.

The FLEXmax Extreme is engineered around the concept that the strongest chain is one with no weak links. In the case of charge controller design, the weak link is typically the cooling fan. Removing the fan removes the greatest obstacle to long service life and high reliability, as fan problems severely limit power output.

The FLEXmax Extreme’s advanced thermal engineering provides full power output from -20 to 45°C without requiring a cooling fan. Because the passively cooled unit can be sealed, circuit boards and other sensitive electronics can be fully protected from dust, dirt, insects, and other external sources of contamination.

Installer features of the FLEXmax Extreme include: “ground agnostic” design to support negative, positive and floating ground systems, increased wire-bending space, oversized terminals for easier installation with larger gauge wire, and mechanical design that permits servicing and replacing all power components while the unit is mounted on a wall and attached to conduit.


The FLEXmax Extreme Charge Controller can not only go anywhere, it can also get there faster by saving precious installation time. It is a fitting companion to OutBack’s renowned sealed FX inverter/charger line and demonstrates the company’s ongoing commitment to providing clean, reliable power anywhere it has the potential to transform lives.

Technical Specifications


  •   FLEXmax Extreme Specifications
    Nominal DC Input Voltages 12, 24, 36, 48, or 60 VDC (Automatic adjustment at startup)
    Maximum Output Current 80 amps @ 45° C with adjustable current limit
    PV Open Cirvuit Voltage (VOC) 150VDC absolute maximum coldest conditions / 145VDC start-up and operating maximum
    Standby Power Consumption Less than 0.5 Watt typical
    Power Conversion Efficiency 98.1% @ 80 Amps in a 48 VDC System - Typical
    Charging Regulation Bulk, Absorption, Float, and Equalization
    Equalization Charging Programmable Voltage Setpoint and Duration - Automatic Termination when complete
    Battery Temperature Compensation Automatic with optional RTS installed
    Battery Temperature Compensation Slope Adjustable / 2.0 to 6.0mV per °C per 2V battery cell
    Voltage Step-Down Capability Down convert from any acceptable array voltage to any battery voltage.
    Examples: 72 VDC array to 24VDC battery; 60VDC array to 48 VDC battery
    Programmable Auxilary Control Output 12 VDC output signal which can be programmed for different control applications
    (Maximum of 0.25 amps DC)
    Remote Display and Controller Optional MATE3, MATE or MATE2
    Data Logging Last 128 days of operation - Amp Hours, Watt Hours, Time in Float , Peak Watts, Amps, Solar Array Voltage, Max Battery Voltage Min Battery Voltage and Absorb Time, Accumulated Amp Hours, and kW Hours of production
    Positive Ground Applications Requires Dual-Pole Circuit Breaker for switching both positive and negative conductors on PV input
    Operating Temperature Range -40° to 60° C (Full power output -20 to 40° C with passive cooling, -20 to 55C with Turbo Fan option)
    Environmental Rating IP54 / NEMA 3R
    Conduit Knockouts One 1" trade size (35mm) on both left and right sides; one on the back; two on the bottom
    Warranty Standard 5 year / available 10 year
    Weight Unit 22.6 lbs (10.23 kg)
    Shipping 26.0 lbs (11.79 kg)
    Dimensions (H x W x D) Unit 18.56 x 8.8 x 6.0" (47.1 x 20.9 x 15.2 cm)
    Shipping 9.69 x 11.75 x 22.75" (24.6 x 29.8 x 57.8 cm)
    Options AXS Card Modbus Interface, External turbo fan, Remote Temperature Sensor (RTS)
    Non-volatile Memory Yes
    Field Upgradable Firmware Yes
    Certifications UL1741, CSA C22.2 No. 107.1, IEC 50178, AS/NZS 3100, IEC 61000-6-1, IEC 61000-6-3 FCC Class B, RoHS, CE
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