STAINLESS STEEL BT-Resistance a Concern or Negligible?

[BaronVonEissler]

I bought 4 X VTC6 batteries that were installed[In house] with a Stainless Steel BT. Not a solder blob or Third party BT. Liionwholesale will do it for Only $2/battery for any FT you want. They do have several third party BT batteries.

It got me thinking. First I asked HKJ, then did my own brief research on the BEST metals for conductivity and finally contacted Jon, owner[and engineer] of Liionwholsale to get his take.

HKJ did not do tests on this. He just questioned whether 1.5mm of BT would make a difference? I took it that it would not be significant.

Jon from Liionwholesale did test it: Not quoted,his general words.

He said he tested AC inductance and saw around 13.5 mOhm or so with the button top. Without the button top it’s around 13 mOhm, so it’s really rather negligible.

And for me, I did learn some simple stuff.This is from a website.

Best metals for conducting electricity:TOP 13

Pure Silver,Pure Copper,Pure Gold,Aluminum,Zinc,Nickel,Brass,Bronze,Iron,Platinum,Steel,Lead and in Last place was Stainless steel.

Oh yes,It was a 4 year old thread on here[when I googled SSBT] That got me started on this:Last post #15

Ways to safely put a button top on a 18650?

So yeah that is pretty much my question. What are the best ways to put a button top cap on a 18650 battery? Is using solder a must? Can it float and just use a washer and the heatshrink to keep it in place? What are the dangers? Thanks

Would my SSBT reduce current flow with a noticeable loss of Output? My guess is neglible.

What do you guys think?

PHOTOS of batteries below. They tested an average of 3027mAh on my Opus BT-C3100 2.2

[will34]

Depends more on the attachment method than the material itself. You could have a 0.1mm thin metal sheet on top of your contact and if it’s not welded in place then it will create resistance.

It is widely discussed that most batches of 30Q button tops from Banggood are not secured properly with a battery tab welder but just being held with the shrink wrap. It increases IR when tested with a charger and only gets worse at 10 or 20A draw.

For such a small piece, researching which materials offers least resistance is totally overkill. Most of the time it is best to just get the basics right.