Using 0.2mm 30mm wide nickel strip seems a reasonable option, I’ll try that. Using copper sheet with nickel plated steel strips would be good for ampacity, but there’s a potential for corrosion if it gets exposed to water.
A couple more ideas, for trimming the nickel I bought these,
https://www.amazon.com/We-Memory-Keepers-Corner-Chomper/dp/B0024M5GH4/ref=asc_df_B0024M5GH4/?tag=hyprod-20&linkCode=df0&hvadid=219491607334&hvpos=&hvnetw=g&hvrand=5050810839397229767&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9032737&hvtargid=pla-376720654529&psc=1
ended up using curved lexan scissors
https://www.amazon.com/Integy-Hop-ups-C23053-Curved-Scissors/dp/B00QYZOS7G/ref=sr_1_11?dchild=1&keywords=lexan+scissors&qid=1618688032&sr=8-11
also some small magnets to hold the nickel to the battery as you weld it
https://www.ebay.com/itm/111776513877?chn=ps&var=410767440802&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=410767440802_111776513877&targetid=1068323855990&device=c&mktype=pla&googleloc=9032737&poi=&campaignid=11755692891&mkgroupid=112020227417&rlsatarget=aud-622524042438:pla-1068323855990&abcId=9300462&merchantid=115029001&gclid=CjwKCAjwjuqDBhAGEiwAdX2cj-nlDNaUBl0LwTcqVtCTLZFUgGcOEKDGfjkB0rs756WiX8BiDg42kRoCsvgQAvD_BwE
Just had a very painful battery buy, 150 / Samsung Q30
They where 6.50 each last week.
yeah😭 i bought the same but on nkon .de and it’s only 3 euro /unit but now out of stock every days 8 dollar it’s to much sorry to see that
Yikes that is crazy! P42a batteries are a much better bang for buck at those prices for sure.
Also check out the battery calculator. There is some pricing on there to figure out the best value.
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Welding up pack now! Needing to wait for the electrodes to cool is taking the longest… Kweld with 330F supercap charged to 12v) works pretty well!
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Anyone assembled a pack using pouch cells?
Hello,
I am new to building batteries and I would like to ask for feedback on my battery design: I want to build a 12S4P battery where the cells are stacked inside a waterproof plastic tube. The poles are not welded or soldered together. Instead the cells are pushed towards each other by a spring at the end of the tube (like in a flashlight).
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Is this design feasible? Would this work without welding the cells?
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If I put three of those 12S4P batteries in parallel, is this equivalent to 12S12P (for air travel)? Drawbacks compared to a design where all parallel cells are connected?
Thanks,
Martin
As long as there’s a small current flowing, it’ll work. What are you gonna run with it?
A Flipsky 65161 Motor for foiling. What current does this require?
This requires extremely high current, depending on the quality of the propeller. Maybe 100 amps on takeoff. What kind of propeller are you planning?
I was thinking of the one that comes with the Flipsky kit: Group W7 Water Sports Kit (Includes High Current FSESC75300 /75200 and – FLIPSKY
So maybe 150 amps at start-up. The reason is that it’s the worst commercial prop for e-foils. It is pointed out on the forum all the time, yet more and more builders are buying this prop.
Ok, thanks for the advice. So if I get a better prop it will be around 100 amps. What happens if I do not weld the cells together or maybe just the plus poles. Will the current be unstable or the battery be heating up?
If you need to know this to complete your thesis:-), I would be happy to explain it to you.
You know very well that just spring pressure is used for very simple and simple appliances - TV remote control, desk clock, digital caliper, PC mouse etc etc.
But the e-foil is one of the most demanding devices in the world with regard to very high motor power.
It therefore makes no sense to dwell on the issue of the worst possible way to connect the positive and negative poles of batteries. Another mistake is that your solution does not seem to consider charge protection in the form of a BMS.
Here on the forum there are many examples of very simple, very reliable and very efficient connection of positive and negative battery poles.
Hi @MartinS,
There are people in the esk8 community that use these types of packs. They are call compression packs and they can do very high currents, although I haven’t see any on the efoil side of things.
Personally I’d for air travel, I’d make 4 square packs and put them in a waterproof box on the efoil. Although i thought air travel could only do 100wh max per pack. For my 12s12p it is 36Ah at ~45V for 1620WH. That would seem to require 16 separate packs, and it looks like total is only 300WH, so not sure how that would work.
Also yes that prop stinks. If you are in europe here is a good cheap option: https://www.custommotorsfrance.com/product/propeller-complete/
@Dynamik Have you built an efoil board or made a battery yet?
Thanks for this lead @brycej. I’ve been searching for an air transport solution for the 18650s and wasn’t aware of the compression cell holder approaches. These are helpful.
Next, adapt a way to contain and make them water tight for efoils.
Prior to your post, I saw this post on the forum, which I was considering how to adapt for efoils:
Has anyone here had success building portable efoil batteries for air transport?
If I was going to do it,
Max our series pack with 100WH and you can have 2 spare batteries.
A P42A is about 15WH. So that is 6 batteries in a P row (20-30 minute foil time). Then need 12 or 14 or 16 separate packs for series row.
So You’ll need a family of 4-5 to carry on all your extra batteries, Then connect all the series rows when you arrive.
Seems like a PITA though, I probably would just pay to ship the battery down and built a really robust battery.
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Got the case built for the battery. Hooked up my custom BMS while charging for balancing but it didn’t need to do much at all.
None my glands could fit though the 1/2 inch acrylic so I drilled holes, sanded sharp edges, put a ziptie on the wire inside for strain relief and siliconed the wires in.
Might try and find a better solution in the future.
Added the top with vhb tape and a 1/4 inch piece.
Going to try it out this weekend!
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