A performance curve graph for the Rutland FM1803-2 wind turbine, showing power output in Watts against instantaneous wind speed in m/s, with a blue shaded area under the curve on a white background.
A performance curve graph for the Rutland FM1803-2 wind turbine, showing power output in Watts against instantaneous wind speed in m/s, with a blue shaded area under the curve on a white background.

Off-grid Wind Power System | Marlec FM1803-2 48V 840W Turbine, 9.6kWh Battery, 3kW Inverter

  
By Marlec
Minus Plus

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Off‑grid Wind Power System – Marlec FM1803‑2 48V Wind Turbine 840W, 9.6kWh AGM Battery and Victron MultiPlus‑II 3kVA Inverter

  • Rugged off‑grid wind power system combining a proven 48V Marlec Rutland FM1803‑2 wind turbine with 9.6kWh of sealed AGM storage and a Victron MultiPlus‑II 3kVA inverter/charger.
  • Designed for reliable 230V AC power at windy, exposed, remote UK and overseas sites where there is limited solar resource that need power year-round. 
  • Backed by UK‑based technical support.
  • Options are available: different size battery banks, generators, solar power. Contact us for details and a custom quote. 
  • Important note: this system cannot be combined with an existing on-grid solar installation and is not recommended for use in built-up and inland areas.
  • We can estimate the output from this system on request.

Overview

This off‑grid wind power system brings together the Marlec Rutland FM1803‑2 48V Furlmatic wind turbine, a 48V 200Ah Rolls AGM battery bank (9.6kWh at 48V) and a Victron MultiPlus‑II inverter/charger to deliver dependable AC and DC power for remote applications such as telecoms, monitoring stations, and off‑grid cabins.

The 1.8m diameter Rutland FM1803‑2 turbine is designed for land‑based sites, using a high‑voltage three‑phase alternator and MPC‑2 controller to charge the 48V battery bank, while the MultiPlus‑II provides a 230V AC supply and integrated battery charging when a generator is available.

Key features

  • Proven 48V wind turbine – Marlec’s Rutland FM1803‑2 Furlmatic Windcharger with 1.8m rotor diameter, furling tail protection and up to 840W peak output in strong winds (48V variant).
  • 9.6kWh sealed AGM storage – Four Rolls R12‑200AGM 12V 200Ah deep‑cycle AGM batteries in series for 48V, maintenance‑free with M8 terminals and robust high‑rate performance.
  • Victron MultiPlus‑II inverter/charger – 48/3000/35‑32 model providing 3kVA (2400W continuous at 25°C) 230V output, integrated charger and PowerAssist capability for generator support.
  • Optimised for long cable runs – High‑voltage three‑phase output from the turbine and MPC‑2 controller allow siting the tower in the best wind location while keeping cable sizes modest.
  • Flexible off‑grid architecture – Suitable as a stand‑alone wind system or as part of a wider hybrid setup with solar and generator backup, using Victron’s control and monitoring ecosystem.

Where to use this system

This off‑grid wind power kit is suitable for permanent or long‑term remote installations where continuous or frequent power is needed and site access is limited. Typical use cases include:

  • Telecommunications and data – Remote masts, microwave links, repeaters and IoT gateways requiring stable 48V DC and 230V AC power.
  • Monitoring and control – Environmental monitoring stations, instrumentation, traffic and seismic monitoring equipment.
  • Lighting and security – CCTV systems, street or compound lighting and security infrastructure in off‑grid or hard‑to‑reach locations.
  • Remote buildings – Off‑grid cabins, welfare units, site offices and small off‑grid homes needing reliable power year round.

For safety, compliance and long‑term performance, we recommend installation by a qualified installer using appropriate tower foundations, protection devices and commissioning procedures. Energian can introduce trusted UK partners familiar with off-grid power equipment.

Technical specifications 

  • Turbine type: Rutland FM1803‑2 Furlmatic Windcharger, land‑based wind turbine.
  • Turbine diameter: 1.8m rotor diameter.
  • Number of blades: 3 aerofoil blades, fixed pitch.
  • Blade construction: Individually injection‑moulded, glass‑filled mouldings with nose cone for airflow to the rotor.
  • Generator type: Low‑torque, three‑phase brushless AC generator with high‑power rare‑earth magnets and low‑friction bearings.
  • Generator output (typical): Variable‑frequency AC at approximately 120V line‑to‑line under normal conditions.
  • Yaw system: Sliprings and brushgear enabling 360° free yaw to seek the wind without cable twist.
  • Cut‑in behaviour: Aerodynamic rotor runs in approximately 2m/s winds; generation starts at about 3m/s.
  • Protective furling: Mechanical furling tail system; wind speeds over 15m/s (approx. 35mph / 56kph) cause the offset tail fin to turn the turbine out of the wind, reducing rotor speed and generator load.
  • Construction materials: Aluminium, stainless steel, glass‑filled injection mouldings and high‑quality paint finishes.
  • Available voltages: 12V, 24V and 48V versions. (This system uses the 48V model.)

MPC‑2 Controller (included)

  • Primary functions: Transforms and rectifies high‑voltage AC from the turbine to DC for battery charging; electronically optimises turbine performance; prevents battery overcharge.
  • Operating modes: Low and high wind modes switch power ratios to optimise rotor performance across varying wind speeds and increase daily energy yields.
  • Battery regulation: Charges continuously until batteries reach 14.4V per 12V segment, then switches to stall mode; resumes charging when voltage falls to 12.5V per 12V segment (for lead‑acid settings).
  • Thermal protection: Over‑temperature electronic shutdown with fan cooling; turbine is temporarily stalled when high internal controller temperatures are detected.
  • Display and controls: Backlit LCD display showing mode, battery volts, Amps, Watts and Ampere hours; Run / Stall / Reset button.
  • Sensor connections: Temperature compensation sensor; optional remote voltage sensor for batteries located more than 1.5m away; serial data socket for remote display or programming; remote shutdown connection point.
  • Run/Stop switch: Separate switch supplied for connection between turbine and controller to park the turbine when required.

Technical specifications – Rolls R12‑200AGM batteries (per battery)

  • Model: R12‑200AGM, Rolls AGM 12V deep‑cycle sealed maintenance‑free battery.
  • Nominal voltage: 12V.
  • Rated capacity (20‑hour rate): 200Ah.
  • Capacity at 100‑hour rate: 220Ah (at 25°C).
  • Capacity at 10‑hour rate: 162Ah (at 25°C).
  • Internal resistance: 4mΩ (fully charged at 25°C).
  • Capacity vs temperature (20‑hour rate): 102% at 40°C; 100% at 25°C; 85% at 0°C; 65% at −15°C.
  • Self‑discharge at 25°C: 91% remaining after 3 months; 82% after 6 months; 64% after 12 months.
  • Maximum discharge current: 2000A (5 seconds) at 25°C.
  • Reserve capacity: 400 minutes at 25A; 100 minutes at 75A.
  • Cold cranking amps: 1500 CCA at 0°C; 1300 CCA at −18°C.
  • Charging (constant‑voltage, at 25°C): Cycle use 14.6–14.8V; float use 13.6–13.8V.
  • Terminals: Standard F‑M8.
  • Dimensions: Length 530mm; width 209mm; height 214mm; total height including terminals 219mm.
  • Weight: 56.0kg per battery.

Technical specifications – Victron MultiPlus‑II 48/3000/35‑32

  • Model: MultiPlus‑II 48/3000/35‑32, 230V inverter/charger.
  • DC input voltage range: 48V DC, 38–66V.
  • AC output: 230VAC ±2%, 50Hz ±0.1% (adjustable to 60Hz).
  • Continuous output power at 25°C: 3000VA / 2400W (non‑linear load, crest factor 3:1).
  • Continuous output power at 40°C: 2200W.
  • Continuous output power at 65°C: 1700W.
  • Peak power: 5500W.
  • Maximum efficiency: up to 95%.
  • Zero‑load power: 11W (48V model).
  • Zero‑load AES mode: 7W.
  • Zero‑load Search mode: 2W.
  • Transfer switch rating: 32A.
  • Maximum AC input current: 32A.
  • Battery charger: Max battery charge current 35A for 48V model; absorption voltage 57.6V; float 55.2V; storage 52.8V.
  • PowerControl and PowerAssist: Built‑in functions to limit AC input current and supplement grid or generator power from the battery when required.
  • AC outputs: Main output with no‑break functionality; second output live only when AC input is present (for non‑critical loads).
  • Communication: VE.Bus for parallel/three‑phase and system integration; general purpose communication ports; support for GX devices and VRM remote monitoring.
  • Protection features: Against output short circuit, overload, high and low battery voltage, high temperature, AC back‑feed on output and high input voltage ripple (see datasheet protection key).
  • Enclosure: Steel, blue RAL 5012, IP22.
  • Battery connections: Four M8 bolts (two positive, two negative).
  • AC connections: Screw terminals 13mm² (6 AWG).
  • Dimensions (H × W × D): 499 × 268 × 141mm (48/3000 model).
  • Weight: 19kg (48/3000 model).
  • Operating temperature range: −40°C to +65°C (fan‑assisted cooling), humidity up to 95% non‑condensing.
  • Standards: Safety EN‑IEC 60335‑1, 60335‑2‑29, 62109‑1, 62109‑2; EMC EN 55014‑1/‑2, EN‑IEC 61000‑3‑2/‑3; generic immunity/emission IEC 61000‑6‑1/‑2/‑3.

Documents available for download

Shipping and support

Shipping available to the UK, Ireland, Africa, the Caribbean and worldwide. If a shipping rate is not shown at checkout, please contact us on +44 20 8064 0335 or info@energian.co.uk for a quotation.

UK expert support is available – contact us with any questions or support requests via phone, email or live chat, or visit our office for an in‑person consultation.