Foil Drive FM+ 650 Battery
Foil Drive FM+ 650 Battery is backordered and will ship as soon as it is back in stock.
Pickup currently unavailable at The SUP Co x Lymington
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Foil Drive FM+ 650 Battery
Foil Drive FM+ 650 Battery is backordered and will ship as soon as it is back in stock.
Description
Description
The Foil Drive FM+ 650 Battery is the 648Wh Gen 2.5 battery designed for the Foil Drive Assist MAX+ and, with the correct FM+ Battery Adaptor, the Foil Drive Fusion. It gives MAX+ riders the highest-capacity battery option specified for the system, while giving Fusion riders a lighter alternative to the larger Fusion 860 when outright maximum runtime is not the priority.
With a 43.2V nominal voltage, 15Ah capacity and 648Wh of stored energy, the FM+ 650 is built for riders who want meaningful runtime for surf foiling, downwind runs, flat-water starts, wake riding, wing foiling and light eFoil use without automatically carrying the weight of the largest Fusion battery.
Just as importantly, this is more than a larger battery pack. The Gen 2.5 design incorporates an intelligent battery-management system, Bluetooth communication, internal thermal management and an integrated nose cone within a one-piece moulded housing. The result is a battery designed specifically around the newer 43V Foil Drive platform.
Important compatibility note: the FM+ 650 is not compatible with the previous 40V Foil Drive Assist MAX Gen 2. If you own an older Foil Drive system and are unsure which generation you have, contact us before ordering.
Where does the Foil Drive FM+ 650 Battery fit in the range?
The easiest way to understand the FM+ 650 is as the all-round battery at the centre of Foil Drive's new Gen 2.5 platform.
On Foil Drive Assist MAX+, it is the main 648Wh battery and gives the system its combination of strong thrust, useful session length and relatively compact installed dimensions.
On Foil Drive Fusion, the FM+ 650 provides another option. Fit the required FM+ Battery Adaptor and you can trade some of the Fusion 860's maximum capacity for a lighter battery underneath the board.
That makes it particularly interesting for Fusion riders who sometimes want the full 864Wh Fusion 860 for long powered sessions but would prefer less battery weight for surf, downwind or more performance-orientated foil-assist sessions.
Browse our wider Foil Drive and foil assist range if you are building a complete setup rather than replacing or adding a battery.
Why choose the Foil Drive FM+ 650?
- 648Wh capacity: substantial energy for repeated starts, longer surf sessions, upwind motoring and more time on the water.
- 43.2V Gen 2.5 architecture: designed specifically around Foil Drive's newer MAX+ and Fusion platform.
- Direct MAX+ compatibility: the FM+ 650 is the principal high-capacity battery for Foil Drive Assist MAX+.
- Fusion compatibility: can be used with Foil Drive Fusion when paired with the correct FM+ Battery Adaptor.
- 3.95kg battery weight: approximately 0.95kg lighter than the 4.9kg Fusion 860 battery itself.
- Strong power deeper into the discharge: Gen 2.5 battery technology is designed to maintain full performance until around 10% state of charge before normal battery sag becomes more noticeable.
- Integrated smart BMS: communicates useful battery information with the Foil Drive V3 Controller and Foil Drive App.
- Internal thermal management: helps regulate battery temperature for more consistent power delivery.
- Integrated nose cone: the one-piece battery design removes the need for a separate nose cone.
- Fast charging for its capacity: Foil Drive quote an average charge time of approximately 85 minutes with the correct 43V charger.
What does 648Wh mean in the real world?
Battery capacity is only useful when it suits the way you actually foil.
A rider holding significant throttle through repeated flat-water starts will use considerably more energy than an experienced surf foiler who uses the motor for a few seconds to enter each wave. For that reason, we would not judge the FM+ 650 by one headline runtime figure alone.
Its real strength is versatility. There is enough capacity to make MAX+ a genuinely useful all-round foil assist rather than a system intended purely for occasional short bursts, while the battery remains lighter and shorter than the Fusion 860.
Surf foiling
The FM+ 650 makes particular sense for riders looking to increase wave count. You can motor out, reposition between peaks, use powered acceleration to enter weaker swell and recover more quickly after a fall without needing to conserve every second of motor use.
Downwind foiling
Repeated starts are one of the quickest ways to consume battery. The 648Wh capacity gives progressing downwind riders useful reserve for failed starts, resets and motoring back into position, while experienced riders can use shorter bursts to maximise overall session length.
Flat-water starts and pumping
For flat-water training, a larger battery means more attempts before returning to shore. Rather than exhausting yourself repeatedly trying to generate board speed, Foil Drive can provide the initial acceleration and allow you to concentrate on foil control and pumping.
Wing foiling
MAX+ with the FM+ 650 can provide reliable assistance through marginal wind, help smaller boards release and generate enough speed for the foil and wing to take over.
Wake and swell riding
Having power available on demand makes it considerably easier to accelerate onto passing wake or weak rolling swell, particularly when there is not enough natural energy for an unassisted start.
Foil Drive FM+ 650 runtime
Foil Drive provide the following indicative runtime figures for the FM+ 650. They are useful for comparison, but should not be treated as guaranteed session times.
| Use | Indicative runtime |
|---|---|
| E-Foil / sustained powered use – intermediate rider | Approximately 31 minutes |
| E-Foil / sustained powered use – advanced rider | Approximately 52 minutes |
| Surf foil – intermediate rider | Approximately 40–50 minutes |
| Surf foil – advanced rider | Approximately 55–70 minutes |
Foil Drive's comparison testing is based around an 80kg rider, 800cm² front wing and 5'0" 40L board. The eFoil-style test uses flat water at approximately 70% throttle, while the surf test uses approximately 3ft swell and less than 5 knots of wind.
Your own runtime can differ substantially. Rider weight, foil efficiency, board drag, propeller choice, motor height, current, sea state, water temperature, number of restarts and throttle use all make a difference.
An experienced surf foiler using five or ten seconds of motor assistance per wave may spend considerably longer on the water than a rider continuously using the motor to remain powered.
FM+ 650 with Foil Drive Assist MAX+
The FM+ 650 is particularly well matched to Foil Drive Gen 2.5 Assist MAX+. The complete combination is designed to balance power, runtime and ride feel rather than simply maximise battery size.
With the FM+ 650 fitted, MAX+ has an installed battery-system length of approximately 540mm. The battery's integrated nose profile keeps the package clean and removes the separate nose-cone arrangement used on some previous-generation Foil Drive batteries.
For riders using MAX+ for surf, wing, wake, downwind and flat-water starts, this is the battery we would normally expect to sit at the heart of the system.
It is particularly suitable if you:
- want substantial runtime rather than the lightest possible assist setup;
- regularly perform multiple powered take-offs;
- use Foil Drive to motor between waves or bumps;
- are progressing and expect to need more restarts than an expert rider;
- use smaller boards or foils that require more acceleration;
- want one battery capable of covering several different foil disciplines.
Using the FM+ 650 with Foil Drive Fusion
The FM+ 650 can also be fitted to Foil Drive Fusion using the correct FM+ Battery Adaptor.
This creates an interesting second configuration for Fusion owners.
The standard Fusion 860 battery has 864Wh capacity and weighs approximately 4.9kg. The FM+ 650 has 648Wh capacity and weighs approximately 3.95kg, making the battery itself around 0.95kg lighter.
You give up some maximum battery capacity, but for surf, downwind, wing and other sessions where board response matters more than the longest possible continuous runtime, that trade can make good sense.
| Battery | FM+ 650 | Fusion 860 |
|---|---|---|
| Capacity | 648Wh | 864Wh |
| Amp hours | 15Ah | 20Ah |
| Nominal voltage | 43.2V | 43.2V |
| Battery weight | 3.95kg | 4.9kg |
| Battery length | 460mm | 575mm |
| Main strength | Balance of capacity and lower weight | Maximum Fusion runtime |
For Fusion installations, the FM+ Battery Adaptor is required and adds additional hardware to the complete installation.
Gen 2.5 smart battery technology
The move to Gen 2.5 is important because the battery is now an active part of the wider Foil Drive electronics ecosystem rather than simply a reservoir of stored power.
Intelligent Bluetooth battery management
An integrated battery-management system communicates with the Foil Drive V3 Controller and Foil Drive App. Compatible system information includes state of charge, battery identification and battery-health data, giving you a clearer view of what is happening inside the system.
Power deeper into the battery
The Gen 2.5 architecture is designed to deliver full performance down to approximately 10% remaining charge before the normal reduction in output associated with a depleted lithium battery becomes more noticeable.
That matters most when you are using significant throttle. A battery that retains useful voltage under load makes the final part of a session much more predictable than one that begins to feel noticeably weaker much earlier in its discharge cycle.
Internal thermal management
The battery incorporates thermal management intended to keep internal temperatures more stable during use. This helps support smooth, consistent power delivery across the session.
One-piece battery and integrated nose cone
The FM+ 650 uses a one-piece moulded design that incorporates the battery and nose cone into a single unit.
This is useful for several reasons:
- there is no separate battery nose cone to select or fit;
- the external shape is designed around smoother water flow;
- fewer separate external components simplify installation;
- the battery mass is positioned around the foil's centre of lift;
- the sealed construction is designed for demanding marine use.
The battery is rated to IP69 water and dust resistance. As with every electric watersports product, that does not remove the need for correct inspection, connection care, rinsing, drying and storage after use.
Charging the Foil Drive FM+ 650
The FM+ 650 must be charged using the correct 43V Foil Drive charger used by the Gen 2.5 MAX+ and Fusion platform.
Foil Drive quote an average charge time of approximately 85 minutes.
The compatible charging system also supports Storage Mode, which is useful if the battery will not be used for an extended period.
Foil Drive recommend storing the battery at approximately 30–60% state of charge rather than leaving it fully charged or deeply discharged for long periods.
A charger is not included with this standalone FM+ 650 Battery. A suitable 43V charger is supplied with complete compatible MAX+ and Fusion systems, or should be purchased separately if required.
Foil Drive FM+ 650 compatibility
Compatible with
- Foil Drive Gen 2.5 Assist MAX+
- Foil Drive Fusion when used with the correct FM+ Battery Adaptor
- Foil Drive 43V charging system
- Foil Drive Battery Caddy when used with the appropriate FM+ Battery Adaptor
- Foil Drive V3 Controller and compatible Foil Drive App functions when installed within the appropriate system
Not compatible with
- Foil Drive Assist MAX Gen 2 40V systems
- Older Gen 2 MAX batteries and chargers simply because they share the MAX name
- Foil Drive Assist Slim battery installations
- Gen 1 Assist or Assist Plus battery systems
Do not choose a Foil Drive replacement battery based only on its physical appearance or connector. Voltage, battery-management architecture and system generation must all match.
If you are uncertain whether you own a Gen 2 MAX, Gen 2.5 MAX+ or Fusion, contact The SUP Company with a photograph of your electronics unit and existing battery before ordering.
Foil Drive FM+ 650 Battery specifications
| Product | Foil Drive FM+ 650 Battery |
|---|---|
| Generation | Gen 2.5 |
| Foil Drive SKU | FD401 |
| GTIN | 9361123003493 |
| Battery type | Rechargeable lithium-ion |
| Rated capacity | 648Wh |
| Amp hours | 15Ah |
| Nominal voltage | 43.2V |
| Maximum voltage | 50.4V |
| Battery weight | 3.95kg |
| Battery dimensions | 460 x 125 x 55mm |
| Installed dimensions with MAX+ | 540 x 125 x 55mm |
| Installed dimensions with Fusion | Approximately 658 x 125 x 55mm |
| Nose cone | Integrated – separate nose cone not required |
| Water and dust resistance | IP69 |
| Average charge time | Approximately 85 minutes with the correct 43V charger |
| Recommended storage charge | Approximately 30–60% |
| Certifications | UN38.3, CE, FCC, WEEE, RoHS, PSE, IP68 and IP69 |
What's included?
- 1 x Foil Drive FM+ 650 Battery
- 1 x FM+ 650 Battery Carry Case
Not included: Foil Drive electronics unit, motor, controller, 43V charger, Fusion FM+ Battery Adaptor, Battery Caddy, foil, mast or board unless specifically stated as part of a separate package.
Looking after your Foil Drive battery
A Foil Drive battery is a substantial part of the value of the complete system, so sensible battery care is worth making part of your normal post-session routine.
- Use only the correct Foil Drive 43V charging equipment.
- Inspect the battery and electrical connections before every session.
- Do not use a battery that has suffered significant impact, swelling or visible damage.
- Keep electrical contacts clean and maintain them according to Foil Drive's instructions.
- Rinse and dry your complete Foil Drive installation correctly after salt-water use.
- Allow equipment to dry before closing it into storage.
- Avoid leaving the battery fully charged for prolonged periods.
- For longer-term storage, aim for approximately 30–60% state of charge.
- Follow the battery and charger manuals supplied with your Foil Drive system.
Foil Drive FM+ 650 Battery FAQs
What is the capacity of the Foil Drive FM+ 650?
The FM+ 650 has a rated capacity of 648Wh or 15Ah at a nominal 43.2V.
Which Foil Drive systems use the FM+ 650?
It fits Foil Drive Gen 2.5 Assist MAX+ directly. It can also be used with Foil Drive Fusion when the correct FM+ Battery Adaptor is installed.
Will the FM+ 650 fit my older Foil Drive Assist MAX Gen 2?
No. The FM+ 650 belongs to the newer 43.2V Gen 2.5 architecture and is not compatible with the previous 40V Assist MAX Gen 2 system.
Is the FM+ 650 the main battery for Foil Drive MAX+?
Yes. The 648Wh FM+ 650 is the high-capacity battery specified for the Gen 2.5 Assist MAX+ platform.
Can I use the FM+ 650 with Foil Drive Fusion?
Yes, but you need the correct FM+ Battery Adaptor. It is not a direct battery swap without the required Fusion installation hardware.
Why would I use the FM+ 650 instead of the Fusion 860?
The FM+ 650 battery weighs approximately 3.95kg compared with 4.9kg for the Fusion 860 battery. It therefore gives a Fusion owner a lighter 648Wh option when outright maximum runtime is less important than reducing battery weight. The required FM+ Battery Adaptor adds some additional installation hardware.
How much does the Foil Drive FM+ 650 weigh?
The battery weighs approximately 3.95kg.
How long does the FM+ 650 last?
Foil Drive's controlled examples range from approximately 31–52 minutes for sustained eFoil-style riding and approximately 40–70 minutes for surf use. These are indicative figures only. Rider weight, foil, board, conditions, motor position and throttle use can change runtime considerably.
How long does the FM+ 650 take to charge?
Foil Drive quote an average charging time of approximately 85 minutes when using the correct 43V charging system.
Does the FM+ 650 come with a charger?
No. This standalone battery includes the FM+ 650 and its carry case. A compatible 43V Foil Drive charger is required and is supplied with compatible complete MAX+ and Fusion systems.
Does it need a separate nose cone?
No. The nose cone is integrated into the one-piece FM+ 650 battery housing.
What charge level should I store the FM+ 650 at?
Foil Drive recommend approximately 30–60% state of charge for longer-term storage rather than leaving the battery fully charged or deeply discharged.
Can The SUP Company check whether this battery fits my Foil Drive?
Yes. If you are unsure which generation you own, send us photographs of your Foil Drive electronics unit and existing battery. We would much rather confirm compatibility before you order than have you discover afterwards that you have a different voltage or system generation.
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