Hi @g.gregory8
Thank you, yes it is, but it’s some work to assemble without creating a short circuit 
I’ll start testing next week. It is not that easy to find a good 12cell charger. the cheaper way would be to build 2 6 S packs to use cheap chargers, balancers etc. I’ll report if I recognize something unusual.
@edivory I used PETG - its elastic and worked for the purpose.
Corrosion: Yes, I thought the same. there are 2 options for this problem: you can order the same woven copper wire with tin plating → no corrosion (typically you have a nickel barrier layer on copper and then tin, otherwise you’ll get copper whisker) but the minimum order was 25 meter for the tin plated version. I don’t need so much.
The other option is to plate it with silver by myself. this is what I’m planing to do for the next pack. You can by silver electrolyte on amazon and plate it with low voltages or even without electricity.
amazon: https://www.amazon.de/Silbergel-50-Alternative-Silber-Elektrolyt-versilbern/dp/B00XPRSN8Q
https://www.amazon.de/Silberelektrolyt-250-versilbern-Versilberung-Galvanik/dp/B01ALCOM0A/ref=sr_1_6?ie=UTF8&qid=1515531577&sr=8-6&keywords=silber+elektrolyt
You know that PETG is very brittle at impacts or quick sudden deformation? It is elastic and giving only if deformation is slow and gentle. Hit it with a hammer and it shatters like glass spitting debris all around. I made some plastic parts for motorcycle and some cracked off at potholes just supporting own weight. Have you tried Nylon?
My 16AH 10C Hobbyking has become a bit swollen (although I thougt that I did treat them nice).
They are and have always been very even on the celll voltage but I suppose they need to be replaced.
I would like your opinion about this battery 27AH pack.
It can deliver 50A continous and 150A peak using LG 3,4AH cells.
Did anybody find anything better or cheaper?
https://www.aliexpress.com/item/Free-Shipping-Battery-48v-27ah-1800W-for-LG-18650-Lithium-Battery-48v-with-2A-Charger-50A/32809337477.html?ws_ab_test=searchweb0_0,searchweb201602_5_10152_10151_10065_10344_10068_10342_10343_10059_10340_10314_10341_10534_100031_10084_10604_10083_10103_10307_10615_10301_10303_10142,searchweb201603_2,ppcSwitch_5_ppcChannel&algo_expid=0be1b33b-71ba-4240-b51a-db737d3c2514-1&algo_pvid=0be1b33b-71ba-4240-b51a-db737d3c2514&priceBeautifyAB=3
Got a picture of the batteries?
I’m working with a company in China for Lithium Ions battery packs for efoils. they make custom sizes both packs and waterproof packs. Also, there is another California based company working on pack specifically for efoil for everyone here based on 12S packs and/or 2x 6S packs.
Its best for us all if we can get away from the LIPO for safety, number of recharges, and ease of shipping. I’ll keep you posted as I get more details/specs/photos/and their pricing.
@Jan the 150A peak is fine, but I feel the 50A continuous may be a little low as you will be straining the battery/wiring all the time. Electronics don’t like to be run at their limits. Just my 2 cents.
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What kind of continuous current have you guys been measuring when using your equipment?
I could not find a pack that could handle more amps and I do not like to weld my own.
I am not to keen on Lipos either but a lot better with a BMS though.
Fine, I hope you will find a better solution and I will wait and see what you will find.
My old battery is this one
It has swollen 2-3mm on one side.
I use almost the same type, i use 6 pieces of 16Ah 4S. So i combine them to have 32Ah 12S. Do you remember how that swelling happened?
I use a frame to assemble them, which puts slight pressure on the laminates, so they actually cannot swell in that direction.
I am not sure if its dangerous with coffee bag style. Its a good practice for using large LiFePO4 cells and i have seen this on many electric vehicles to prevent swelling. Actually the clamping system is sold together with the cells.
https://de.wikipedia.org/wiki/Lithium-Eisenphosphat-Akkumulator#/media/File:Hotzenblitz_ThunderSky-LPF60AH.JPG
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Exactly the same type here. I will add some padding to mine to protect from crashes.
just be sure to eliminate any sharp points that a puffed cell can puncture itself on. Its still best to have a bit of foam around the cell to allow for expansion
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I discovered the swelling after not touching them for 6 weeks and they were about half full.
Maybe at some point they have been a little wet, not much.
I got this offer, I ordered 35AH with Sanyo cells, some should be possiible to get with 100A BMS almost the same price… Conact: Nancy Zheng Email: sales03@herculesi.com
SHENZHEN HERCULESI TECHNOLOGY CO.LTD.
Address: 902, Longhua subdistrict office Huayun Road, Hefa Touzi Building,
Longhua Distric, Shenzhen, China 518110
Web: www.herculesi.com Tel: 0086-755-23739502 Fax: 0086-755-86327276
Conact: Nancy Zheng Email: sales03@herculesi.com
To: Feb. 25th, 2018
The price we quoted is on DDP price bases and our offer will be valid until March. 25th, 2018.
Lithium Battery Cell Combination Door to door Price
(with shipping cost)
48V 26.1A
13S9P
Panasonic NCR18650PF 2900mah Total USD 704.50 (by PayPal)
48V 27Ah Samsung INR18650-30Q 3000mah Total USD 799.00 (by PayPal)
48V 31.5Ah Sanyo NCR18650GA 3500mah Total USD 879.50 (by PayPal)
48V 31.5Ah LG INR18650-MJ1 3500mah Total USD 810.00 (by PayPal)
Spot welded with pure nickel strips
80 Amp max continuous balancing function built-in BMS
=/>150 Amp peak discharge current
Discharge connector: Anderson
Battery size: 18026070 mm
Battery weight: about 6 kgs
Accessory: 54.6V 2A charger
48V 35Ah
13S10P
Sanyo NCR18650GA 3500mah Total USD 982.50 (by PayPal)
48V 35Ah LG INR18650-MJ1 3500mah Total USD 908.00 (by PayPal)
Spot welded with pure nickel strips
80 Amp max continuous balancing function built-in BMS
150 Amp peak discharge current
Discharge connector: Anderson
Battery size: 20026070 mm
Battery weight: about 6.5 kgs
Accessory: 54.6V 5A charger
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where is shipping too?
It is for Europe (Sweden)
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Is anyone on here making custom battery packs or know of a good supplier (with good price of course)? Or is it still best to get the cheap multistar lipos from hobbywing?
Has anyone tried the low profile Alien Power Systems battery?
Alien 10S 22000mah 30C Lipo Battery FLAT
Seems like it should have enough power
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Wow, that is not cheap! 
I’m going to make my own 18650 cell unit to avoid those high prices from laptop batteries. Yes, I know they wont all have the same capacity and what not and it can be unsafe but ill see how it goes