How does soldering affect your cells in terms of heat?

Quick video where you can see with termal gun how it affect the cells. I would say its negelectable as long as you use proper soldering iron!
Highest point was like 70C fraction of a second after lifting the iron. Spot welding do transfer the energy more locally in smaller area but that still gets hotter in that area. The total energy from the soldering in short burst is small.

For those interested and with ideas we can always add more tests to it. I let the video show for it self and I let people decide if its a problem or not!

This was a video response to DIY Ebike schools video regarding it and I wanted to test myself.

Elegant. What iron are you using

This sort of video is great for people who are new to this. Some people assembling battery packs haven't got much experience with soldering, and going for a bigger iron to reduce heat exposure in a cell is probably counter intuitive.

As a further test I guess you could also cycle test new cells soldered vs spot welded. Max charge and discharge rates repeatedly on a few of each method and see if one degrades or fails faster than the other. I don't have any new cells, and I really don't want to put time into that sort of test......

Geek: Its 20++ years old so dunnot. I have linked some in and im guessing its 2-300watt. It got this massive copper tip that just does the job quickly.

neilmc: Yes further testing would be good but i guess we wont see any difference atleast not in my case. Perhaps on those hammered with heat. Buit thats just a guess and for proper result someone need to test it

What solder are you using?

60/40 with flux. Some basic cheap stuff but i found that work best as overall solder. Dont have to add anything when solder.