Can I get some feedback on my spot welding for my 18650 pack

Tks TarzanHBK!!

Because I still had to solder series connections and balance leads.

It’s to keep solder splatter out then it will be fish papered over…

Can I get some input on this welding mess as well pls

Your initial welds look hot. It’s possible you didn’t have a solid connection between the strips and the pulse caused the spark elsewhere. I’d find some more old liion to test on.

By look hot do you mean good or “too hot”?

Was able to reproduce the crazy spark in the meantime with your suggestion. I was welding in kind of an awkward position so the top nickel plate was not making proper contact with the underneath one.

In future I will make sure I always put enough pressure on the weld.

Do you know why the Nickel on Nickel weld is so easy to pull off? The one on the battery sticks like hell. I didn’t get the feeling like increasing pulse time up to 50ms really made a difference besides larger burn marks. Do I need a stronger car battery?

I’m starting to get the feeling that a 420A Battery is just not powerful enough to weld two sheets of .2mm Nickel together. I think increasing the pulse time is just spreading the heat out instead of creating a more powerful weld in a small spot. Will try to get a better battery and report back.

Ask @darkkevind he uses 320a and said in his YouTube video it is more than powerful

Quick question: I tried to use my V1 Balu spot welder again after like 2 years now and used a 15ms weld time for starters. Some of the spots look burnt some don’t - but what bothers me most is that I can rip the nickel off with pliers. Is that normal? How hard does it have to be to rip them apart?

Ideally you want to rip the nickel and not simply undo the weld, a piece of the nickel should stay on the cell

If you can easily rip it then increase the time a bit, if even increasing you can’t get it to stick the current is to low

What are you using as power supply?

Yeah there is some leftover nickel on the cell after prying it off.

I am using a starter battery from a campervan with 95Ah

what increases the durability of the welds:

  • make sure your battery is charged fully before welding
  • use a strong, high current battery
  • clean your welding tips (this is a good one - i had lots of problems in the beginning before i figured this out). Use a file to clean up any black marks on them, so that the copper is nice and fresh again

I spotwelded yesterday with it and had 10 ms for the first nickel layer of 0,15 mm nickel. Cleaning the tips and charging your batt should do the job, if it worked before.

do you also have the issue of the welder making like 10 spots perfectly fine woithout any spark and then there is one random spot where it burns a hole in the nickel? I am just wondering if my welder has an issue and if I need to replace it with a new one.

Also: I tried to weld two nickel tabs together - even at 15ms I was able to pry them apart quite easily. Is there a trick to welding two layers of nickel?

I don’t remember having these issues two years ago for my 10S3P battery :thinking:

Hmm ya, that doesnt sound good and no my welds are all strong and nice. Like i said i only have problems when my battery is a bit more discharged or when the tips were blackened due to sparks over time. Two layers of nickel should be doable with 15 ms with mine.