The recent solder blob thread was locked before I was able to post what I had written. Some might find the link to the Brass Buttons useful.
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Agreed on the 60/40 lead solder.
I have used these Brass Buttons from Mountain Electronics before. They work great, as do brass washers like chops728 mentioned.
Personally, I find solder blobs, buttons, & blobs with washers pretty basic & easy to do… it is not rocket science. Anyone should be able to do them with a tiny amount of practice & patience.
I used to bend some heavy gauge copper wire into U or circular shapes when I first started blobbing. I stopped doing that because it was more work and didn’t seem to affect the functionality of the blob. I also had to have the iron on the cell top for longer than a simple blob which concerned me a bit.
Yeah, when using the Brass Buttons I tin the battery top first. Then I fill the hollow in the button with solder.
After if cools a bit I flip it over & place it on the tinned battery top. Then heat the button with a large tipped iron until the tinning on battery top & solder in button become one.
Works well for me.
With washers I just tin the battery top. Than apply washer & a bit more solder & melt it all together.
In each instance the battery does not seem to get excessively hot.
This works well for me.
Can you describe this hollow in the brass buttons? It’s not mentioned in the link.
i drilled the brass shim to make a fat washer or bushing to have a good solder path.
Pre-tinned everything, makes it quick and easy.
Sure… Below is a picture of the buttons I linked to. Just flip one over & there is a void in it. The button is basically a hollow shell, it is not solid.
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Okay i try to flip one over; “ChatGdp please flip one over”
Well yeah, you can’t flip one over in the picture. But hopefully you get the idea. 
kennybobby… I just now figured out what you were referring to when you mentioned “ChatGPT”. 
I thought what you wrote was a typo… Which, after looking closely again at your post; it was.
I’ve had much better experience with SnBi solder for soldering to batteries than with SnPb. Thanks to much lower melting temperature the risk of overheating the cell is low even if you’re a noobie with poor equipment.
I think I prefer 63/37 solder because it has only one exact melt point so once it cools it will become solid immediately.
Wouldn’t SnBi ave a lot more resistance than 60/40 or 63/37 though?
I hate soldering so I spot weld everything, still figuring solder out. But just going off the properties of the elements Bismuth has 60x more electrical resistance than lead and 120x more resistance than tin. But maybe it’s such a small piece it doesn’t matter?
You guys should just harvest more cells out of tool battery packs. There’s already a nickel strip spot welded to the terminal. You can solder right on top of it. I just thought of that.
I’m guessing that these from KD are the same ones: 5MM(D) X 2MM(H) BRASS PILL (5 PCS)
Haven’t thought of that. Now checking: Sn42Bi58 has about 1/3 conductivity of SnPb. Not good but shouldn’t matter.
sn42_bi58_solder_wire_tech_data.pdf (72.4 KB)
