Battery Search For Efoil Build

Hi all, I just joined this forum, I am a high schooler doing an Efoil build as a project. I recently purchased this kit from Flipsky: Group W7 Water Sports Kit (Includes High Current FSESC75300 /75200 and – FLIPSKY

I was wondering what battery I should use for this, if you can send links, that would be greatly appreciated.

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That is great school project!!

I’m new to this so I don’t feel qualified to answer your question but many here have a lot of experience.

I would suggest you provide some more detail on which motor and VESC you chose in that package along with what some of your design criteria are - run time, weight ,expense, build or buy etc.

There are lots of threads here that discuss this issue so also encourage you to read about the many options available.

These are the options that I chose when buying the kit. I’m looking for a battery that is 72v, 20ah. I’m probably going for around 30 minutes of ride time. I want to stick with it being under 500 dollars probably.

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Why do you want a 72v Battery?

Be careful, batteries declared as 72V deliver peak 84V (20s) and will fry your VESC
The 75300 is for 18s max
Trampa rates it for 16s max to allow for spikes.

Most used Batteries with the 65161/65162 Motor here are 14s or 12 s, more than enough to get foiling.

If you buy a battery pack don’t go to low on Ah, otherwise the pack will not be able to deliver the necessary A, depending on the cells used in the pack you need a certain amount of parallel series. And cheap packs = low current even with many parallels

I build a battery pack of 12s6p Molicel P42A which gives me at the moment 55 min of pure ride time. As I fall frequently I suppose ride time will get even better when I have less starts.

I got everything I needed to build the battery pack, including Cells, Ni strips, cables, connectors, smart BMS, shrink wrap etc. and even the spotwelder incl. LiPo for 500€ (and hours and hours of study). But beware, building a high power battery pack is dangerous an can set your house on fire

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I could add that in water 60v max is the admitted safety limit. For Li-Ion, building a pack greater than 14s (x4.2V max = 58.8V, “s” for series) could be deadly if you have a leak current in water. It is for this reason that commercial brands have adopted the 14s battery pack. When they want a lighter battery, they just decrease the capacity (Wh) in their “nano” range by decreasing the “p” number (parallel) eg 14s14p to 14s7p.

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Thank you for the help! If you don’t mind, can you send me the link to all the parts you used for the batteries, and do you know if they would ship to the US or if they’re only for the UK.

What do you know about this company It looks like I could just build a battery here, do you think I can trust this?

Hi dreznik I have used:
Molicel INR21700-P42A
Cell Holder 1326p cut down to 12s, but they have also 14s
Pure Nickel Strips 0.2 mm and doubled the series connection
Smart BMS 120A UART

Kapton Tape, Cable, Anti Spark XP90, Shrink tube in 260 and 400 mm from Ali

Mini Spotwelder from Amazon, modified according to Luca
3s 5000mh LiPo from Amazon

My battery was determined by the size of the case: I use a Max300s Case strapped to my Wingfoilboard (the Max004s I bought first was not waterproof - fortunately I testet it beforehand).

Last ride was 13.85km (1h of fun). As I have to drive 3h to lake Garda and back I now will build a second battery pack to double the fun

There are a lot of battery builds here in the forum and in the eskate forum, and many better than mine, so continue studying. Plan first, buy later.

And be careful, there is a lot of energy in these packs: If you accidentally shorten cell blocks with a piece of Nickel strip falling down on your pack it just will glow and melt down if you’re fortunate. If it is thicker like a screwdriver or even just a screw your pack might start to burn If you don’t remove it fast enough!

As to voltaplex, I can’t tell you.


Hello Aemkei77. Where in Lake Garda are you foiling? I am from Carinthia, and from time to time I go to Garda.

I usually starte from Navene. South end with Ora and north end of the lungoriva with Peler, so I can walk back (the walk of shame) if I have a Problem or I loose height with the Wing

If there is enough wind it’s quite full there, best time is between 10.00 and 14.00

Hi Martin @aemkei77 . I plan to use the same MAX300 case as you link. COuld you please provide a photo of how you organize cell in case please ? I have different idea but help will be greatly appreciate To help conception.

how many ‘P’ is your battery ? 12S12P ? 12s14P? thanks !

Hello Jean-Marie,
I have 2 batteries, 12s6p, one with Molicel P42A and one with Samsung 40T3 cells. Both wirh smartBMS. Also in the Max300s is the 75200 Vesc, added water cooling and the bluetooth module for the remote. I printed 2 spacers and added some silica gel so everything fits tight. the box is strapped to my gong hipe wingfoil board.I do ca. 14-15km on each battery.

occasionally 1 latch of the maxcase opens, with a little water entry. i still have to find a solution.


Hi Martin. Thanks for Details ! I orderer today Samsung 40T3 with idea of MAX300. Happy to read you use 40T3 :grinning: I wondering if I will have enough space inside. Which smartBMS are you using please (ref?) ? It seems you have a maytech remote with the RX + relay. I search about Connector too - not seen on your photo. Could you give me what model you use (photo of your installation too :flushed:?) Is it an Amphenol Surlock please ? thanks for your help

[EDIT] I find above you use SP15S008C BMS

@aemkei77 I forgot to mention I will put this on a Fanatic board 105L strapped too.

Cable passing through Cable Glands, not really happy with mine as rhe thread is to short for the (rather thick) case so there was no room for the rubber rings, I used marine sealant instead but would like to find better cable glands

For motor wires I’m using 8 mm bullets in simple waterproof connectors from ali

thanks @aemkei77 for details. it helps me ! :grinning: has the longer threaded glands. I guess most glands are designed for thin metal enclosures not 5mm thick plastic.

Before I got the longer threaded glands, I drilled a hole slightly smaller than the thread and used the gland to self tap into the case, worked great, super tight fitting and there was enough room for the rubber washer.


Hi @aemkei77 Martin ! I receive max300 and Samsung 21700 40t3.
My vesc is far to big to inside this (flipsky 75350). My mistake ! I order a 75200 and will sell the 75350.
Have got some some photo of your diy lion pack please ? From my first test, I don’t understand how you have the whole longest size of max 300 with your diy Li-ion build. .
I initially planned to put 2x6s10p, without BMS, to use my trusted Rc charger.
Thanks !

I have 12s6p, BMS on top
Processing: 20221229_170141.jpg…
VESC is 75200 from Makerbase, as I accidentally fried the first one I got from Flipsky
i charge through BMS with a 18 A 50.4V charger.
I also discharge through BMS

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Thanks @aemkei77 Martin ! Sorry but I can’t open image you post Processing: 20221229_170141.jpg…