eFoil battery

How big is an eFoil battery?

The battery is three things at once: the heart of an eFoil, its heaviest single component, and the biggest slice of what you pay. Today's full-size packs hold 2 to 2.6 kilowatt-hours and weigh 12 to 18 kg. To put that in context, look at e-bikes: the largest bicycle batteries top out around 0.8 kWh. So you stand on the energy of roughly 3 to 5 e-bike batteries. The table below lists the current packs from the major brands, with every figure taken from official manufacturer data.

Those spare-pack prices explain why the battery, not the board, sets the value of a complete eFoil: €2,400 to €5,000 per pack works out at 40 to 45% of the price of a full set. On the used market, battery condition is the first thing to check, ahead of the cosmetics and ahead of which wings come in the box. Our guide to buying a used eFoil works through the checks in detail.

Two columns of that table are worth reading together. Divide capacity by weight and the packs separate out: the SiFly PowerCell LR works out to about 184 Wh per kilogram, the Aerofoils Endurance to roughly 169, the Lift Gen5 to about 158, the Fliteboard Explore Ti to about 139, the Awake Flex XR 4 to about 138, and the Waydoo EVO to about 130. Those figures cover the whole pack, not the bare cells, so what you are really comparing is housings, waterproofing, connectors and cooling as much as chemistry. A heavier pack is not automatically the worse one, but it is weight you carry to the water and back for the rest of the board's life.

The light packs are a different proposition altogether. Lift's LIFTX Light holds 0.54 kWh at 5.6 kg and Fliteboard's Nano Ti 806 Wh at 6.2 kg, which turns the battery from a two-handed lift into something you can carry down to the shore alongside the board. You pay for that in ride time, and in efficiency: a small pack still needs a full housing and a full set of connectors, so the fixed weight is spread over fewer cells.

Voltage is the other number that varies more than you might expect. Awake runs the Flex XR 4 at 86.4 V, while Fliteboard's Explore Ti sits at 50.4 V and SiFly's PowerCell at 52 V. Higher voltage moves the same power at lower current, which is an engineering decision rather than something you feel on the water. The practical consequence matters, though: packs and chargers are brand-specific, and nothing crosses between manufacturers.

Range: how long a charge lasts

Manufacturer promises run from 25 to 45 minutes on the small batteries up to an hour and a half or two hours on the big packs. Lift quotes an average of 90 minutes for the Gen5 battery, Waydoo EVO and SiFly both state 120 minutes, and Fliteboard promises two and a half hours and more than 40 km (about 25 miles) with the Explore pack. Comparing those numbers only goes so far, because hardly any brand says which rider and what speed produced them. SiFly is the welcome exception: 75 kg rider, 15 km/h (roughly 9 mph), large wing, printed right next to the claim.

Out on the water, rider weight, speed, wing size and the state of the surface move ride time more than anything on the spec sheet. A 100 kg rider in the sportiest mode can get half the time out of the same pack that a 70 kg rider gets while cruising. Cold pulls capacity down as well: on an early-season session with water under 10 °C (50 °F), the summer figure is not the number to plan your afternoon around. Our eFoil comparison table sets the published claims side by side.

There is a reason the same battery gives such different answers to different riders. Drag climbs steeply with speed, so the last few km/h cost far more energy than the first few. Flying is the efficient state: once the foil carries you clear of the surface, the motor pushes a slim mast through the water instead of a whole board. A rider who can hold flight for long stretches gets noticeably more out of a pack than a beginner who spends the session taking off, dropping back down and powering up again from a standstill. Learning is the most expensive thing you can do to a battery, which is worth knowing before you judge your board by your first session.

Treat the published figure as a best case and plan from your own numbers instead. Note what you really get on an ordinary day, in the water temperature you ride in, at your true weight with a wetsuit and a vest on. If a full day on the water is the goal, a second pack is the only reliable answer, and it is also the most expensive accessory you can add to the set.

Charging times and chargers

Charging happens at an ordinary wall socket, but always with the brand's own charger. With a fast charger the big packs are ready in 1 to 2.5 hours: the Lift Gen5 battery goes from empty to full in 140 minutes (80% after 80 minutes), the Fliteboard Explore takes 1 hour 45 minutes and the Aerofoils Endurance 2 hours. Slow chargers ask for 6 to 9 hours, and in exchange they will run off a boat or a generator. A fast charger is a serious purchase on its own, at somewhere around $1,000 to $1,300. Waydoo's inverter charger is the curiosity of the group: it charges the pack and also draws 230-volt power back out of it, which turns your board into a power outlet at the water's edge.

Lift's own numbers show the shape of a lithium charge curve nicely. The first 80% arrives in 80 minutes, then the remaining fifth takes another hour. That tapering at the top of the range is normal behavior for a large pack, and it has a practical use: if you are trying to squeeze a second session into an afternoon, plan around the quick 80% rather than waiting out the tail.

The electricity itself barely registers. A 2.3 kWh pack draws about 2.3 kWh from the wall plus a little charging loss, which at household electricity rates is small change next to what the board cost. The expensive parts of charging are the hardware and the calendar: one charger handles one pack at a time, so two batteries and a single charger means charging them back to back. If you ride from a boat or somewhere off-grid, the slow generator-friendly charger stops looking like the boring option.

Charging safety

The safety instructions read much the same from brand to brand, and they are worth following to the letter: charge with the original charger only, in a dry, well-ventilated place, away from flammable material, on a level, non-flammable surface, and never leave the pack charging unattended, overnight least of all. Let the battery cool down after a session before it goes on the cable, and stay inside the temperature window the manufacturer specifies, commonly 5 to 30 °C (41 to 86 °F). Awake goes a step further and recommends keeping a fire extinguisher within reach of the charging spot, with the explicit warning that a lithium fire must never be fought with water.

The unattended rule is the one every brand repeats, and the reason is straightforward: when a pack of this size does go wrong, it goes wrong fast, and what is at stake is not only the battery but whatever it happens to be standing next to. A garage floor, a few meters of clearance and a working smoke alarm cost nothing compared with the pack itself.

Beyond those shared points, what applies to your battery is what your own manual says. Capacities, voltages and cell chemistries differ between brands, and so do the instructions that come with them, so read the manual properly once before the first charge and keep it wherever the charger lives. If a pack has taken a heavy impact, gone deeper than its rating allows, or simply looks, sounds or smells wrong, that is a question for the manufacturer's service department and not something to settle on the charging shelf.

Lifespan and warranty

Strange as it sounds, the obvious question (how much capacity is left after how many cycles) gets no public answer from any manufacturer. What you can see instead are the warranty terms, and those speak clearly enough. Awake, Waydoo and SiFly all draw the line at 24 months or 300 charge cycles (Awake additionally accepts a claim only once capacity has fallen below 70%). Lift is the most candid of the group: it treats the battery as a consumable with no capacity warranty at all, and the warranty that does exist depends on charging the pack at least every three months and keeping the firmware current. Fliteboard simply gives two years, battery included, and at Aerofoils the warranty is tied to a mandatory service inspection every 12 months.

Read those conditions before you buy rather than after. Requirements attached to charging intervals, firmware updates and annual service visits are obligations you have to meet in real life, in the middle of winter, when the board is in the garage and nobody is thinking about it.

For what it is worth, 300 cycles is a lot of riding. Go out twice a week, every week, and you would still be close to three years away from that number. The normal pattern with lithium packs is a slow decline rather than a sudden failure, so what you notice first is that a session ends earlier than it used to, not that the board stops working. Careful storage and the manufacturer's own charger are what stretch that curve out. When you are buying new, the battery price belongs in the total from the start, and a second pack belongs in the plan if you want full days on the water. We have run those numbers on the eFoil price page.

Flying and transport: the 160 Wh ceiling

Planning to take the board along on a flight? Bad news. The international air-transport rules airlines work to put a hard ceiling on passenger lithium batteries: up to 100 Wh travels freely, 100 to 160 Wh needs the airline's approval, and above 160 Wh the battery does not go on a passenger aircraft at all. eFoil packs hold roughly 500 to 2,600 Wh, which is 3 to 16 times the limit. The manufacturers make no secret of it: Fliteboard and SiFly state outright that the battery cannot go on a passenger plane, Awake prohibits air transport entirely, and according to Lift the pack may travel only with a certified dangerous-goods carrier, in its own approved transport case.

The practical lesson: eFoiling is a sport you drive to. By road, an undamaged pack carried for private use is usually straightforward to move, though transport rules for lithium batteries differ by country, so check the ones that apply to you before a long trip or a border crossing. For a flight, the realistic options come down to shipping the battery ahead as freight or renting a board where you are going. That single constraint shapes travel plans more than most people expect, and it is worth settling early: book the board at the destination, or accept that the flight and the foil are two separate trips.

Where you may actually ride once you get there is a separate question with no global answer. Rules differ by country and often by individual lake or stretch of coastline, so check the local regulations before you launch. And if you are still choosing between boards, start with the battery: capacity sets your ride time, the pack sets much of the price, and the charger decides how your day is organized. The rest of the decision is covered in our eFoil buying guide.