OutBack Power FM100 FLEXmax 100 MPPT Charge Controller

Add Ons
Pricing is an estimate, kits are customized for each building variation.
Pricing does not include freight shipping. Request a shipping quote and get a free roof layout.

The FLEXmax 100 is the latest innovation in Maximum Power Point Tracking (MPPT) charge controllers from OutBack Power.

The advanced FM100 MPPT algorithm offers increased energy harvest from the PV array than other MPPT controllers. The FLEXmax 100 delivers both higher voltage and higher power, offering improved flexibility and performance.

OutBack network communications and OPTICS RE compatibility allows the FLEXmax 100 to be remotely programmed, monitored and controlled via any internet connected device providing unrivalled system integration.

The FM100-300VDC is a top-of-the-line high performance, efficient and versatile charge controller for your advanced power system.


  • 100A output for up to 5kW of charging 
  • Compatible with 24, 36 and 48VDC battery banks 
  • Updated MPPT software algorithm improves energy harvest vs other controllers 
  • 300VDC open-circuit voltage limit enables 2-string configuration that minimizes BOS 
  • Fully OutBack network integrated and programmable 
  • Programmable auxiliary control output for smart load controls 
  • Up to 99% efficiency 
  • Standard 5 year warranty upgraded to 7,000 W of nameplate solar power at 48V

  • Specifications

    Nominal Battery Voltages: 24, 36, 48 VDC

    Maximum Output Current: 100A

    Maximum Array (STC Nameplate): 3500W / 5250W / 7000W (charging output limited to 100A at battery voltage)

    Battery Temperature Compensation: Adjustable from 2mV/cell/°C to 6mV/cell/°C

    Warranty: 5 years

    Dimensions: 22 x 8.8 x 6 in / 55.9 x 22.4 x 15.2 cm

    Weight: 18.3 lb / 8.3 kg

    Customize my box

    Customize My Box

    We'll custom design this system for you and calculate how many solar panels you need to meet your goals.
    Request customized kit

    Solar Calculator

    How much do solar panels cost? Use our easy solar panel calculator to get a quick estimate of how many solar panels you’ll need for your home.
    Size My Solar System

    Free Solar Roof Layout

    Our engineers use state-of-the-art software to conduct a PV analysis and draft a free layout of solar on your roof, included with our complimentary quote.
    Get My Free Layout

    Get Started
    With Solar

    We'll help you figure out your solar needs!

    Fill out the form for a complimentary solar panel quote that includes a custom solar panel layout using satellite technology and a breakdown of solar energy production, federal tax credit and energy offset.