Foil Drive Assist Max+ (FM+ 650) Battery

From Foil Drive

The FM+ 650 Battery sits at the intersection of runtime, weight and cost, and is your “go to” battery option for both Gen2.5 Fusion and MAX+ units.

With 648Wh of capacity, Foil Drive's 43V architecture unlocks powerful, consistent thrust and endurance for extended surf sessions and upwind-downwind runs, through to wake riding, pumping, flatwater starts and light eFoiling.

Engineered to work across both the Fusion and the MAX+ units, it gives riders the flexibility to move one battery between two very different setups. For MAX+ riders this is your highest capacity battery, with plenty of runtime for a full surf session. Fusion riders simply add the FM+ Battery Adaptor for a lighter, more manoeuvrable alternative.

Not compatible with the Gen2 MAX. The Gen2 MAX runs 40V architecture and the FM+ 650 is 43V, so the two cannot share batteries or chargers.

Gen2.5 Battery Technology

Gen2.5 battery technology lets you use more of the battery. It performs deeper into the cycle, so on the water you get full power delivery right down to around 10% before you notice the sag that every battery eventually shows.

• Charging
  • The FM+ 650 requires a 43V charger, supplied with your Fusion or MAX+ system. Charge time averages 85 minutes. An industry-first Storage Mode limits charging so batteries can be stored for long-term health — Foil Drive recommends storing between 30% and 60% state of charge.
• Intelligent Bluetooth BMS
  • Sends accurate battery data to the V3 Controller for clear percentage and status readouts. It also connects to the Foil Drive App, where you can name each battery, track its health and check its state of charge — so you can check the surf cam and your charge level at the same time.
• One-piece moulded design
  • The battery and nose cone are a single sealed unit. That improves water flow and durability, and puts the weight directly over the foil's centre of lift. No separate nose cone required.
• Internal thermal management
  • Keeps temperature stable and power consistent through the full discharge curve, for smooth thrust from start to finish.

Runtime

Runtime varies with skill, weight, gear sizing and conditions. These are indicative figures based on real-world averages, for an 80kg rider on an 800cm² wing and a 5'0 40L board.

eFoil figures are flatwater at roughly 70% throttle; the intermediate rider has many touch-downs and multiple restarts, the advanced rider none. Surf figures are 3ft swell in under 5kts of wind; the intermediate rider leans on the motor heavily and does not pump between waves, the advanced rider uses the motor moderately and links some waves by pumping.

Tech Specs

• Rated Capacity: 648Wh
• Amp Hours: 15Ah
• Nominal Voltage: 43.2V
• Max Voltage: 50.4V
• Battery Weight: 3.95kg / 8.70 lbs
• Dimensions: L460 × W125 × H55mm
• Dimensions Installed: L540 × W125 × H55mm with the MAX+ · L658 × W125 × H55mm with the Fusion
• Nose Cone: integrated, not required
• Battery Type: Lithium-Ion
• Water Rating: IP68 + IP69 water and dust resistance
• Certified: UN38.3, CE, FCC, WEEE, RoHS, PSE, IP68, IP69

Package Includes:

• FM+ 650 Battery
• FM+ 650 Battery Carry Case

Compatible With

• Foil Drive MAX+
• Foil Drive Fusion — with the FM+ Battery Adaptor
• FM+ Battery Adaptor
• 43V Standard Charger
• Foil Drive Battery Caddy — with the FM+ Battery Adaptor

Note: Proper care is essential for battery longevity. See your battery and charger user manuals for full guidance.