DIY battery pack question

[Ruben]

Hello,
I'm currently in the process of making my own battery, I read a lot about it and decided to order some tabbed 18650 Samsung 25R cells to make my pack, since I only have an 80W soldering iron and don't have the money for a spot welder.
Now I received my tabbed 18650's, but the tabs seemed flimsier then expected, so I decided to contact the seller to get some measurements, apparently they're 7mm x 0,12mm. After doing some research here this seems way too small for what I need, but some of them do overlap (but for only 50% of the cell-to-cell connection).

My question is now, how do I best go at this pack? Do I cut off the tabs, only leaving the welded part on the top and solder some thicker gauge wire from top-to-top on these tab remains, or do I solder the tabs together and then solder another wire over it? What's my best option?

Also, I'm looking to make a 12S2P pack with a max cont. discharge of about 20A and pulse discharge of 40A.

Thank you very much for your time

 

[dogman dan]

I'd say solder thicker wire if the tabs are too short. Tin that wire first. Get a big fat thick tip for your iron, so you have lots of heat to solder fast.

Practice the soldering a lot on something else before wrecking good cells. Old cells from some shitty laptop power supply maybe.

 

[Ruben]

Thank you for the reply. I do have an iron with a big fat flat tip, and I do have some old cells to practice on. I know it's not a good idea to solder on the tips of the cell, but if it's already tabbed and I'm fairly quick, do you think that would be okay? And is it worth it to try if the solder tabs would be too thin or should I just add the wire without trying first?