@Emenel My kids are 7 and 9. While I wouldn’t trade parenthood for anything, I really cherish the free time I’ve slooowly been getting back as they become more independent.
I agree that building a battery pack is the way to go, if you’re so inclined. My concern was that if I didn’t seize the moment and buy some batteries I’d never finish the project. I can always go back and tweak things after I’ve got a proof of concept.
Great news, things started showing up to my door! Gong Allvator V2 L foil got in this week:
And just got the pre-cut blank from Greenlight Surf Supply.
Didn’t realize it would come cut in half, but that’s probably just my ignorance showing. I got some of this to glue to two halves together.
Now I’m trying to figure out what to do about a battery. I thought about getting the Turnigy 20000 mAh battery to save time—but as I mentioned above, some people on another thread suggested against. So I think I’ll TRY (key word) to build one. I might be owing @torqueboards a lot of drinks soon since he’s offered to help me NOT blow my hands off.
Right now trying to figure out how many 18650 30Q’s to buy and what type. They seem similar but vary a lot in price. These are $5/each, these are $1.93, and these are $2.40. Is there some big difference that I’m not picking up on?
The expensive ones lock genuine, the cheap ones look like knock offs. Stay with genuine quality cells from a reputable seller. Too risky to get a burning pack.
Samsung 40T 21700 and Molicel P42A 21700 are also good cells and less spot welding.
@sat_be I was afraid someone would say something like that. Makes sense though, thanks for the heads up! It sounds like even building a battery pack will cost about $700-900. Sound about right? Makes buying the pre-mades tempting.
[quote=“sat_be, post:31, topic:15470”].
Samsung 40T 21700 and Molicel P42A 21700 are also good cells and less spot welding.
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I assume the bigger mAh means less batteries? That would be helpful, another good tip.
Exactly, less cells. If you bild a smaller battery it ends up chaeper (at the cost of a shorter run time) 12S8P =96 cells.
They’re different Molicel batteries, but @deeproot mentions here that the compromise is more on speed than run time. But that’ll obviously depend on rider, board, etc. In any case, thanks @sat_be for the info. I’ll check prices on both Samsungs and the Molicels. Gotta try to keep this as cheap as I can.
Go with the Molicel P26A Cells. I ordered from here: Molicel P26A 18650 2600mAh 35A Battery
Fast ship in USA, they are $3.90/cell now. My battery is 14s12p - 168 cells. I get about 1hr of runtime. My Samsung 30q battery performs exactly the same as my Molicel battery. I have over 50 rides on each battery now and see no difference other than the cost!
Tips:
The one thing I would change if I make another board would be the length. I would shorten the front of the board by about 10-12" just to make it smaller.
Hope this helps, cheers!
@Emenel nice! It’s all coming along.
@deeproot What was the main difference between Flipsky propeller + Fliteboard?
Or it could cost whatever the price of your house is when it burns down. Newbies shouldn’t start out with 200 cells in series / parallel. Learn with a much smaller battery or it could get painful physically and financially.
Lithium fires are pretty crazy to manage… Potentially impossible to manage if you are sleeping and it’s on fire in the garage.
The Molicel P42A are even cheaper per per capacity than the P26A. 4Ah vs 2.6Ah (14.4 vs 9.36Wh, 3.9$ vs 5$. 8 to 10P with 12-14S should be big enough. A 14S10P battery with P42A has a nominal capacity of 2.016 KWh. I run one with 96 cels (12S8P, 1380Wh) which gives me 40-50min riding time, dpending on the wing and average speed.
I hear you, makes perfect sense. And who knows, I might still follow you on Turnigy and see how it goes, for that same reason (time). We’ll see which way the wind blows. In any case, keep me posted on your progress!
@uberfoil What I hate to say is that you’re probably right, and this has crossed my mind more than once. I don’t have any other reason to build a battery, that I can think of. This is the first time in my life the idea has occurred. You think I’d be safer building a bunch of smaller batteries and then connecting in series for my first build? Or should I get another hobby that requires smaller batteries?
This is also helpful, and I know you mentioned that less spot welding. It’s good to know I have other options that will keep the cost down. I guess I’ll shop the options and see what makes sense.
50 min. sounds good. You happen to know what average speed gets you 50 min? Or what your max speed typically is?
I just keep hearing that the Flipsky prop is garbage. I have never actually used Flipsky prop. I have only used the Fliteboard prop and it’s excellent. Smooth and silent… and only $45. It works very well with the Flipsky 65161 - 120KV. My max speed is around 20mph at 80% throttle. I have never gone over 80% throttle. At 20mph+ over choppy water things get a little scary. I hit a big fish or something at 20mph and the board launched me 15 feet into the air, the foil sliced my leg open, had to apply a turnicate (zip tie) call 911 and get stitched up on the dock, lost lot’s of blood. So speed runs don’t end well. My average cruising speed is around 12-13mph. This is the butter zone and I have the most fun at this (safe) speed.
Probably best to just buy one.
I was suggesting you cut your teeth on a small battery (for something else…) before jumping right into a massive efoil battery. Don’t try and connect a bunch of small batteries for an efoil. Well, I did read about a guy on here who uses drill batteries connected in series…
Anyway, it’s dangerous for a “total newbie” to connect up 196 cells for a first try. Smells like fire to me, unless you have some experience building batteries.
Wow, hate that this happened to you. Glad it wasn’t worse. I’m suddenly feeling inspired to add this to my wish list.
That was with max 33km/h and average 23km/h, so slow. Here is a metr log from another session that last 38min with an average speed of 26km/h Apr 11, 2022 - metr.at | o79Vf
https://youtu.be/S_GW5gZ88s8 Thanks for asking Emenel! My oldest son (19) recorded this yesterday (in Michigan, USA). I need to work on the fuselage placement as the main wing seems to be a bit far forward. I moved it back an inch and had really good results with a reduction in porpising. Water was extremely cold and my muscles refused to let me stay in the water any longer (put in the docks with wetsuit in AM, but later in the day I couldn’t get my wetsuit back on due to being wet and I am fat now).
Also your Gong equipment looks fantastic! I will definitely go with the Allvator v2 for my upcoming winter build in 6 months from now. I saved a ton of money by printing my own main fin, and using Crazyfoil for everything I could up to this point, so hope to learn a bunch more this summer with tweaking what I have. Overall, a very successful project so far.
@tritodd It’s alive! Haha, I love it man, looks fun. Were you able to stand up and fly a little bit? I agree with you, looks like a very successful build, especially for a first try. Need to see more videos from Michigan soon, hopefully the water will warm up a little.
P.S. wet suits are notoriously hard to get on, no shame!
