Dilemma on serial conn. amp req. for 12s2p 50A max 21700

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#1

Hello, folks. First time posting.

I am designing electric roller skis using electric skateboard parts. I am currently working on the battery.

I am planning on using two 12s2p batteries (one in each ski). As you know, skis are long and narrow, so I was planning on orienting the batteries along the ski either flat or stacked two high (probably in a “honeycomb” configuration).

The problem I am having is that for my serial connections, I have this dilemma:

  1. I can connect the material (say, 0.2mm nickel) to the batteries, but the material is too thin to allow 25A
  2. I can get material that can handle over 25A (say, 0.3mm nickel plated copper), but I can’t get my spot welder to weld it

(#1 above is a bit of an assumption–I built my spot welder, tried to weld the nickel plated 0.3mm strips, and it just got hot and didn’t weld. I contacted the seller who said that no hobby welder would be capable of welding 0.3mm nickel plated copper–doh!)

Here is a simplified sketch of the problem:

BatteryDesing

Components in question:

  1. Motor: https://flipsky.net/collections/e-skateboard/products/flipsky-bldc-belt-motor-6354-140kv-2450w-for-electric-skateboard
  2. ESC: https://flipsky.net/collections/electronic-products/products/mini-fsesc4-20-50a-base-on-vesc-widely-used-in-eskateboard-escooter-ebike
  3. Battery: https://liionwholesale.com/collections/batteries/products/molicel-npe-inr-21700-p42a-45a-4200mah-flat-top-21700-battery-authorized-distributor?variant=15913210675294

Ampacity chart I’m using: https://www.endless-sphere.com/forums/download/file.php?id=248217&mode=view

1 Like
#2

Have you thought about soldering braided jcopper or wire over the top of the nickel?

#3

You’d should use 30mm*0.2mm pure nickel strip. Go look in the battery builders club. If you do this you should be good.

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