The "perfect" battery cell for DIY e-foil (2025)

I am researching for the “perfect” battery cell for my DIY e-foil which is using a Flipsky 65161 motor.

Must-haves:

  • ~1h ride time (~30Ah @ 52v)
  • 3000w continuous, 6000w peak (65161 motor)
  • 14s, 52v
  • 500 charge cycles

Nice-to-haves:

  • total cell cost < 300€
  • compact pack size
  • fast charge

Battery pack size (normal grid / zig-zag grids):
(zig-zag formulas: (sqrt(cell_d^2-(cell_d/2)^2)(count-1))+cell_d, cell_d(count+0.5) )

18650 14s10p - 266 x 190 / 233 x 200 / 276 x 167
18650 14s12p - 266 x 228 / 233 x 237 / 276 x 200
21700 14s6p - 308 x 132 / 270 x 143 / 319 x 117
21700 14s8p - 308 x 176 / 270 x 187 / 319 x 155

Note: The discharge current from manufacturers seems overrated as very high temperatures are allowed. We don’t want that in an enclosed box, and it is also bad for cycle life. I am using batemo.com + others for more realistic figures. Prices are mostly from nkon.nl

For 18650 cells I’m considering these options:

  • Murata vtc6 - 3120mAh, 20/30A, €2.85 / €399 (14s10p), 10400w
  • Samsung 30q - 2500mAh, 12/20A, €1.82 / €255 (14s10p), 6240kw
  • Molicel p28a - 2800mAh, 19/26A, €2.79 / €430 (14s11p), 10868w
  • Samsung 25r - 2500mAh, 15/22A, €1.50 / €252 (14s12p), 9360w

For 21700 cells I’m considering these options:

  • Samsung 50s - 5000mAh, 17/29A, €2.60 / €218 (14s6p), 5304w
  • Molicel p50b - 5000mAh, 25/39A, €4.39 / €369 (14s6p), 7800w
  • Molicel p45b - 4500mAh, 23/38A, €2.92 / €286 (14s7p), 8372w
  • EVE 40pl - 4000mah, 34/44A, €2.50 / €280 (14s8p), 14144w
  • Ampace jp40 - 4000mah, 45/60A, €2.35 / €263 (14s8p), 18720w

Looking at the table above it seems sensible not to use a high-powered cell and go more towards a medium-powered one. Since we have a lot of cells in paralell each cell does not need to supply that much. All cells above can perfectly fine support the motor with 3000w continues and 6000w peak.

Samsung 50s looks to be the best choice. Low price, high capacity and good enough current rating. It has had critics to be overrated with a bloated amp rating, and that may very well be, but for this application it looks spot on to me. I might up the pack to 14s7p to get a bit more headroom on the amps since 50s is known for heating up a lot, and some extra ride time cannot hurt :slight_smile:

There is no perfect battery cell.

Every rider has a different set of preferences and based on those different cells create their preferred battery.

Those numbers are quite high, you can probably cut them in half. But you’ve listed premium power cells anyway so not really an issue.
You could also try and estimate the weight and volume of the various packs. Less weight is better obviously. Volume wise it is nicer to have the weight concentrated closer to the mast and the wing’s center of lift and less weight cantilevered out in front

I ordered some bak 45d for my first tow boogie.
13s12p $2.8 usd per unit.

EVE 50pl - here is the real champion.

Very good cell that one! Tabless, huge discharge, but probably expensive? Very nice in a low-p battery pack for foil assist, but will be overkill in a “normal” efoil

Plan A is to use my kite-foil board and a waterproof box with battery and vesc somewhere on top. Probably on the front😅. Plan B is to make a new board out of xps foam, glass fibre and epoxy.

I think it’s going to be very hard to get going and stand up on a kitefoil board. My current kitefoil board is only 13l I think it would sink with the weight of an efoil added plus gaining speed and standing up on such a tiny board would be very hard. I build and efoil with a Fliteboard Pro 67l it’s great I love it but now I’m working on a ligher build just for fun. I’m going to use a Flipsky 6384 with the battery ESC bolting under the board like Foil Drive but a bigger bigger mainly for efoil but it can work on any board. Sort of like the Lacroix Vortex but smaller and a sleeker shape to push through the water. I think I will need another boar though. I’m thinking of gettinga wing board in the smaller sizes. Ideally it would be great to have a board that can efoil and kitefoil at the same time.

The price that the suppliers offered me was only slightly higher than 40Pl.

Today I rode in e-foil mode and I think that 63100 is much better suited for these purposes than 6384.


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I already bought the 6384 so I’ll give it a try. I already have an efoil with the 65161 and it’s great so I wanted something lighter and more portable. I’m planning something like you all under the board with about 1KW 14S4P with LG 5 AH cells. How big is your board? What wing?

145x58 64L. Battery 12s 3p 12 A/h. I would like a smaller board, 35-40 liters. Something like Cabrinha Bump. The wing (Gong Veloce 1600) and mast were just lying around in the garage, and now I finally found a use for them.

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I have used Panasonic NCR18650 PF on some quad copter builds. They are amazing and live up to their specs. I have a 4s3p pack thats 10 years old and still getting almost rated capacity out of it. 10amp max continuous discharge.
I have just learnt to tow foil behind a little rubber boat with 15hp. Super keen to turn it into an E-Foil to give me some more flexibility. Been looking at motor and battery options.
I know everyone is different but what sort of average power are people drawing during flight? Need to allow for full throttle in the specs to get up but would imagine once foiling you would only need a fraction of that power. That will be a big factor in choosing the right size pack for what Im looking for.
Cheers

I am just over 90kg and with a gong curve xl at 25kph use 1000-1100watts in a straight line. motor 65161 10s and fliteprop.