what’s the diameter of the positive terminal 
of a 21700 battery?
I imagine its not standard. Different manufacturers will have different sizes.
Samsung 30T and 40T, 9mm.
so would it be best to use 9mm nickel strip?
No, not necessarily. The wider the nickel, the more current it can handle.
1 Like
if it’s bigger isn’t there a bigger chance of a short because there is more of the nickel above the negative terminal
I get what you’re saying but with proper insulation rings, it’s not a problem.
1 Like
are your insulation rings plastic? i ordered those green fish paper ones
Fish paper rings… No sharp corners… Nothing pressing on the nickle… You need enough nickle to carry the amperage of the battery as mentioned above… Or ya weld n stack… Weld n stack… To carry the load
These are made of the same material that are inside the cell terminal. They’re plastic but not sure what kind exactly
ok thanks
1 Like
ok ty
1 Like