Hi
About to spend £350 on 2 x 20000 mah 6S Hobbyking Lipos? Is it false economy? Could I build a li ion pack for £350?
In a perfect world I would buy Cells from Fogstar and build my own But…
So based on all this, lipos is probably my best option
The cheap hobbyking lipo’s generally have a low C rating. I use 4 X 15C 12000mah in a 2 series, 2 parallel configuration and they get a little warm and are becoming puffy after only 1 year.
I am currently building a 18650 pack. I have never done this before, but there is so much info and help here and on YouTube.
It’s well worth considering instead of lipo’s.
However, I do also use 2 16000mah Tattu lipo’s which have performed much better than the hobbyking turnigy brand. But still get a little warm.
Thanks, how many cells would I need?
I’m building 2 x 6s 15p packs, which is 180 Samsung 25R cells. Thís will give me a 37500mah pack.
I agree with Roger, and did infact that. Never build such a pack before (and no foil either 
) but the difference is remarkable. No puffing, no hot batteries. I am very happy with them after using them a couple of hours so far. I did 2x 6s-14p using samsung 30Q batteries and bought a spot welder for this purpose .
Thanks guys, whats the typical cost/spend on such a pack?
Once you factored in the price of welder too, ±£500
I still use the same 20A 6s packs from Hobbyking, and mostly 4x 16A 6s of the same brand. Both work and keep going, but never drain them below 3.7V if you want to use them for more than few times!
Now I’ building 2 18650 VTC6 packs, for a total cof 12s14p, but weight ain’t near the same, I throw some sparks to the sky already while spot welding them, despite I should know what I’m doing… it takes time and iny opinion is worth only after having already finished the efoil and WATERPROOF board for good, if you know what I mean.
18650 are dangerous almost as Lipo, chemistry is the same and you add the building factor to the math (joint, strip quality etc). It’s worth because I can tailor the pack on my needs, also I can make a 2s14p to add in series and get the 14s battery finally… but it don’t come cheap nor as easy as buy a good Lipo.
It is not the same chemistry
18650 cells of quality brands are much more safer then lipos
500 Pounds are about 650$.
Isn`t it much easier to take two good Lipos?
https://de.aliexpress.com/item/32986571380.html?spm=a2g0o.productlist.0.0.611f7ecaqKabvt&algo_pvid=74b507ee-c04f-48b2-a661-05304ed1e01a&algo_expid=74b507ee-c04f-48b2-a661-05304ed1e01a-13&btsid=9352dbed-178f-48f2-95b7-d2b9b0985684&ws_ab_test=searchweb0_0,searchweb201602_3,searchweb201603_55
Here you pay about 720$ for 44Ah and you can be shure, it is a good battery.
Ore am I wrong?
I will wait until “black fryday”. Than I buy original Tattu from Gens Ace.
Thanks everyone, I think for this first attempt at getting my board operational I will start with Lipos as its quick and easy and then once I am happy with my set up I will look at Li Ion batteries for phase 2
It depends if you parallel the bank to stick with 22.4V (6s) or as the most of the builders use those in series, at 12s. In that case, it’s a 22Ah battery.
About Lipo and Li Ion 18650 chemistry… it’s about the same (flammable) electrolyte, safety advises are the same ( no overcharge, no discharge below a recommended voltage, do not exceed a max C etc)
@RamsUK: You are right. I will try with a FR motor and 6S. I hope it flies…
If not, 22Ah is too less. And four LiPo-packs are quite expensive 
What do you tink, haów long can I fly with 12s 22Ah?
On a well tuned efoil a little less than half hour, enough for learning (it takes some energy and concentration, half hour is a good session). 6s might be very slow…but it’s doable and good for learning.
Hmmm, that is not realy long time.
I will get some inquiries from dealers. Maybe someone will build the 18650 packs for me.
I can not solder it myself … Or is there anyone here in the forum who would do that? I live in germany
Oh, I get problems …
Who would do me a favorite and puts together the key data that I have to give up as a requirement for the production of a battery pack?
2x 18650 6S and 20Ah are apparently insufficient.
I’ve read that you shut off the engine at 160A in the VESC and the VESC at 90A. Is that really the power that is needed from the battery? And how is it with the BMS? That must work with 160A? Damn, it’s hard, if you do not know …
Generally, I think that the 18650er solution would be better than with LiPos. But not easyer for me…
You will be ok with 2 Lipo, 6s @ 20Ah in series are working for me since day one, I added others to have more flying time and to have a change (double session without having to wait).
18650 to me are good just for 14s (higher voltage=more speed) and to really get some serious run time, but 18650 are not even closer to Lipo as performances, the voltage sag way more and the total capacity drop quite a bit, if the cells are stressed by high amp request as we do. So Li Ion ok for big pack, ok for hi voltage and ok if you don’t care/don’t know what you’re doing, they’re safer in that case. But 2 Multistar 20A made lot of folks happy here.
If you go geared, expect 50-70A max from batteries, let alone motor current at partial throttle which is another story, you don’t care about that when dimensioning battery pack ( you better care when sizing esc, cables and motors, instead!)
Last 2cent, in a hi amp application like efoil, you better off balance charger and no BMS, 100Amps thru mosfets not cooled in a tight spot… I burned 2 mosfet soft switches already, not pleasant and I got lucky, really.
Esc cut off is more than enough and a balance charger works better and safer than a BMS.
