OT: Soldering large 18650/20700 lithium-ion batteries?

Started by John Doe January 5, 2020
whit3rd <> wrote in news:b93be829-bc28-435d-bb8d-

> If you don't use welding, a solder joint to nickel (or nickel-plated) > battery terminals can be made with an overly hot iron,
Except they are almost always steel. wrote in 

>> So, I guess that would be a "Leaf Blower" :-) > > Yes, that's the secret plan: SRB motors on my Leaf Blower. > Wondering if I need a permit to test at Edward's AFB. >
Beans, beans, the musical fruit... The more you eat, the more you'll toot! Light it up and you'll have a hairless ass. But not a whole lot of thrust.
Rick C <> wrote: 

> So where are you getting 20700 batteries? Tesla makes 21700, are > you buying used model 3 batteries?
If Tesla makes them, Tesla isn't the only maker. I have plenty of new (not extracted from a battery pack) Sanyo NCR20700A/B/C, two low current super high capacity Sanyo 21700s, and lots of 18650s. Besides from ordinary sellers, you might find high-capacity high-current Sanyos like the NCR20700C in a premium tool battery like DeWalt's 20 V Max 12 amp hour pack.
Steve Wilson <> wrote: 

> whit3rd <> wrote: >> John Doe wrote:
>>> I am neat, careful, and quick to avoid overheating when >>> soldering. How possible is it to solder a large lithium-ion >>> battery without damaging or degrading the battery? For >>> connecting batteries together. > >> If you don't use welding, a solder joint to nickel (or >> nickel-plated) battery terminals can be made with an overly hot >> iron, a bit of wire solder, and an acid (HCl/H2SO4) flux. Once >> tinned, solder at normal solder temperatures (but you wnat to get >> the surface wet FAST before the battery takes damage, and a cool >> iron won't do it). > > Spot welding is probably safer and more reliable. There are tons > of examples on Youtube and on the web: > > CHEAP Spot Welder DIY (using simple tools) PLANS >
I watched the first video. That video is amazing, for clearly showing how incredibly easier and less time-consuming using the car battery, solenoid, and momentary switch method would be for spot welding battery terminals. That video suggests using a microwave oven transformer is for sustained high current applications like the guy demonstrates at the end of the video. Spot welding batteries takes only a moment per weld. Very different applications and WAY too much work to make five two-cell battery packs. I bought some flux for the first time, yesterday. One benefit to using the extra flux might be putting solder on the iron tip and letting it heat up before applying it to the fluxed terminal, reducing the application time. Seems to work well. Might be a good idea to do that and forget trying to add solder.