I weld the battery myself. The battery in your link has a very low current rating and is not suitable for a foil assistant.
I think they can build a custom battery pack. What is the Maximum Continuous Discharge Current (A) I need? How hard is it to build one yourself? The only specialty item I see I would need is a spot welder and the nickel strips.
I rather buy one then build one but can try if its not too hard.
Before answering, I’ll ask again, what kind of hydrofoil do you use? What is your weight?
Sorry, I wasn’t sure who did you respond too. I wing foil with Neil Pryde surf glide 1850 front wing.
I weigh 160 lbs. the lightest wind I was able to get on foil was about 11mph wind with a 6m wing.
I also have a smaller foils all the way down to 1200 cm2.
I would recommend battery cells with a C-rate of at least 10.
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Battery cells are provided with diferent figures: capacity in mAh then two figures with an objective to maintain temperature under a certain limit to preserve the cell life duration:
- amps continuous discharge rate or CDR, a lower value for a longer running time, typically an efoil drive use,
- amps non continuous discharge rate (NCDR) with temperature limiting value (70 or 80°C), a much higher value with periods of rest to cool down, typically a Foil Drive use. A high NCDR simply means a longer battery life.
There is a respected guy from the vape world called Mooch providing above premium figures. His latest tests are available on the e-cigarette forum. His favourite brands are Molicel, Samsung, LG, BAK, Sony.
From @Strongarm BOM in 6s3p:
| Item | Spec | Quantity | Price (aud) |
|---|---|---|---|
| Cells | 21700 Samsung 40T - rated 4000mAh | 18 | $306.00 |
Mooch has rated this Samsung 40T discharge to 30A (7.5C) continuous and 40A (10C) non continuous.
MOLICEL P42A, 4200mAh, prefered by Mooch over a Samsung 40T, 30A/40A too
These are 2019 batteries.
What’s new in July 2023 still shown by Mooch ??
- 18650 cells can reach a 15C NCDR max rate discharge current: 2700mAh reaching 14.7A
Ex: Molicel P28B - 40A 2800mAh 18650 - 21700s are still 10C but capacity has increased by 7% to 4500mAh in a new 45B model which doesn’t justify the 60% price increase over the 42A
Ex: Molicel INR21700-P45B 4500mAh - 45A
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I’m curious, why is 10c required? Just to keep the battery as small as possible? still the number of runtime will be limited, a 6s pack in 3p with high power cells would get you about 10mins, is that enough? Going to 4p is only 420 grams of batteries and a 21mm wider box.
600s, 120x5s starts seems like a lot but i guess you use the drive for positioning too when you have it?
For long efoil riding I have an efoil. I only need a foil assistant for take off, and then pumping or riding waves, so yes, weight matters.
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Alright, understood! How much ride time or starts do you get? More than one session?
Usually my session lasted about half an hour. I can’t tell you the number of starts, the fact is that when I mainly used the Foil Assistant, my start technique was not particularly good. Now I use Foil Assistant mostly to test new motors or controllers. I built a tow boogie with two 6384 motors, currently building one with 63100 motors and planning another one with 65161 motors (I want to take off on a 15 liter kiteboard) and ride it most of the time.
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interesting topic.
I am a windsurfer and recently I have been trying to learn wingfoiling.
I have a fantic board and a 2400 fanatic foil.
I would like to build such an assist drive myself.
ideal would be with folding propeller. Is there a recommendation which motor fits best to a folding propeller? Where can i find the stl files for the folding propellers?
I am still in the research faze of my first build. Looking for a good battery choice without going the DIY route. I found this LiPo 8s1p battery from Turnigy and was wondering if I can use one of the XT90 Y connectors to combine 2 or 3 of these in parallel. Do you see any issues going this route?
Links below
[Turnigy nano-tech 5000mah 8S 65~130C Lipo Pack w/XT90 | HobbyKing]
[Amazon.com: XT60 Parallel Battery Connector Male/Female Cable Extension Y Splitter 3-Way 14AWG Silicone Wire for RC Battery Motor (1 Male to 3 Female) : Electronics]
https://www.amazon.com/Parallel-Connector-Extension-Splitter-Silicone/dp/B0BG129J62
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eligrinfeld
Have you had any feedback from anyone that has installed the Maytech kit?
Thank you
No. But I found this complete kit and was wondering about it. Besides possibly a less powerful motor vs 6384, the motor looks like already waterproof and has ceramic bearings.
I wonder if someone can confirm that this is a good kit to use for the first build. Combined with the lipo battery above and waterproof case, I am thinking it will be powerful enough to use an assist.
Just for reference I’m 160 lbs, riding a wingfoil 130 litter board with 1850 cm medium aspect foil.
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6384 motor - buy hybrid stainless/ceramic bearing to replace.
80A flycolor version3 esc 45-100$
10s3p battery with molicel 2170 batteries
Flypsky controller – simple to setup/use and has GPS which is a necessity for info
Then 3d printer. Voxelab Aquila S2 cheapest that prints at high temp. print your own parts. Lots of things break over time. A necessity. A BARGAIN right now 170USD !!! No shipping- direct from manufacturer. $
Print your propeller and appropriate motor mounting from files from this forum. OR just ask people what they use
Get a plastic waterproof box of you liking
Wire/bolts etc etc
Get all from aliexpress
There I have done all the hard work for you
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To be honest - get the 6384 motor.
get the flipsky remote controller- way easier to setup/use
get the flycolor esc – simple no hassle – you will need to connect it to a heatsink - preferably exposed to water ( glued onto box with a hole to access it)
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Thank you gzmann Hoping to get it soon
gzmann
Thank you for the info
have the following:
6384 120kv - in process of changing to ceramic bearings
Flipsky remote controller and Vesc
8s3p battery pack
Plastic box
Have ordered the 80A Flycolor v3 esc
So need to ditch the Flipsky Vesc and machine a thick Al heatsink
does the flycolor come with setup instructions?
If I stumble can I have your PM to point me in the right direction
Thank you
eligrinfeld
Thank you for the response
Any photos of heatsink examples for the Flycolor 80A. Thanks