How to Spot Weld Nickel Strips onto 18650s - DH30 Portable Spot Welder

So I got this spot welder to fix my xiaomi pro2 scooter's battery pack .. turned out I sucked at spot welding; main gotcha - go easy on the downward force !

[techguy]

You are absolutely right. That's my finding as well. The reason behind it is that when you apply alot of pressure, you're basically lowering the resistance at the point of weld contacts, which means you require more current to achieve the critical welding tempereture, something that the cheap small welders can not produce. The industrial battery tab welders exert about 3-10kg pressure on the tips, and they can back it up by 10000A of current or more, so they have no problem. With these cheap welders apply firm pressure first to make good contact and then low pressure is the way to go.

[njfulwider]

Best trick to get a feel for tab welding. Use a small kitchen scale. I made a video on this. You get so many new builders claiming what they purchased or what the made diy, saying the device is broken or not working. When in realty they press to hard or not hard enough. Once you figure out the pressure, you'll get great welds 99% of the time👍👍👍👍👍👍

[futuregadget_v.]

Built my own welder from one of those cheap controller pcbs and a modified microwave transformer. Worked well when I first tested it using copper zirconium electrodes. But today I had problems when I wanted to use it. Thank you for this video, now I know what's the problem!

[oziermuhammad]

I have been puzzled why I my device too often wouldn't power up after it appeared to be fully charged. I'd open the device only to find the nickel strips had worked loose. Now I know. Thank you so much.

[soulshinobi]

I just bought a similar spot welder and you may very well have saved me a week of grief

[m.semenyshyn]

What is the principle of welding batteries? I understand the basics and that the welding spot should have the highest temperature for the shortest time. We have a spotter with a bunch of settings: first welding, second and third, where the second welding is the main welding and the third is hardening. There are also peripheral settings such as pause between pulses, current rise and fall times.

So let's get down to business: the first and last welds should not have as high a current as the second. The first weld prepares the nickel strip for welding, the second welds it directly, and the third releases the strip.

We have two main problems that I still can't figure out:

1. Why do the electrodes "stick" to the workpiece? According to my observations, this is due to the cross-sectional area of the electrode tip in contact with the nickel tape. On the one hand, a smaller contact area creates better welding, but the electrodes stick 👉👈 On the other hand, a larger area cooks worse. By increasing the current, the workpiece overheated too much and still nothing happened)

2. One electrode cooks and the other does not. In the case of DC welding, this is understandable. The "positive" electrode, where the current enters the battery substrate, welds better than the "negative" electrode, where the current leaves the battery. However, with AC welding, this is illogical for me, because the current flows back and forth across the workpiece.

Maybe someone has a few gigabytes of information about welding batteries?) I want to absorb all the text from anyone that is related to welding batteries

[ChibiKeruchan]

that actually make sense. coz the factory type of spot welder are spring loaded. in which if you press it, it will make a lot of pressure because of the spring but once it get press and the spring bounce back and the pressure is gone. and all of that happen almost instantaneously

[martinwinlow]

Ah-ha! I wondered why my first use worked OK but second try (some weeks later) all my welds were really weak (I was really pushing down hard because the nickel tabs of the battery pack I was working on were rather uneven). Lowering the pressure *a lot* allows good welds with only half power (I have a '650A max' 'LCD Portable Spot Welder' branded SeeSii - 7500mAh).

Thanks very much for posting your video but I'd change the title to something like "How to Avoid Weak (Capacitive) 18650 Spot Welds" as I came across it very much by accident.

[-Gunnarsson-]

Also the distance between your sticks make a difference. Dont place them to close. You want the current to enter the battery not just take a short cut over the nickel.

[damiancaza-cleypool]

This is the whole game right here!!! Thank you

[abramzacharias]

Thanks for the video. I got a spot welder that you have to push down to trigger the switch. It makes sense that it'd heat up more if the current only goes through the top plate instead of both

[firstnamelastname]

cheers, yes it helps, thank you. I have the same model. the instructions aren't great. the shop i bought mine from gave instructions to press lightly but the 'manual' didn't mention it. the number '24' is the induction being detected (i think).. and the 'trigger level' is the minimum induction at which it will weld.

[leeoconnor]

Thank you ! I'm going to try this for myself. Iv been pressing hard and having the same issues. Much appreciated.

[DavideSacco]

That's a nice metal box ;-) even thought I was kind fond of the other one... more classy

[khalilkh]

Realy Nice information wich spot welder is this? Thanks 😊

[Seneslau]

That's what I got too. Then I've started to press less, made it better but also from time to time I get a more violent weld that results in side burned holes through the nickel. So the secret is somewhere between ferm and gentle press. Also my electrodes are standard copper ones but after ten dots they are blunt..don't know how others can solder in videos like on a machine gun to a fixed electrodes station for example. I have to hold the metal fille near by and stop after a few cells, is this normal?

[camielkotte]

This is exactly what i needed. thx a thousand amps

[Sharan-totm]

Ahoj, máš pěkně udělané video, díky👍😎

[Zodliness]

Very true, too much pressure creates a dead short and prevents an arc forming. Less pressure means higher electrical resistance, resulting in a much higher peak spot temperature. Shame these portable lithium welders handle .1mm strip just fine, but aren't really capable of welding .2mm nickel very successfully, which is common on most pre-assembled packs.

[hxjj]

Is there a chance that the spot weilder pointers need to be brushed down a bit to made them more pointy? Cause right now the points look 3mms flat