This video shows you the inside and usage of the 30€ LCD Battery Spot Welder that you can sometimes get for as low as 26€ from Aliexpress: s.click.aliexp... Follow me on Twitter: / atc1441
Do you have any idea if there is any battery protection circuits between the battery and the powerbank/MCU electronics? And how much current draw (or self-discharge) this device has when turned off? I had a similar spot welder from Ali (without display or powerbank feature, though) that seemed to lack any battery protection and did not turn off properly, so after it had been lying on a shelf for six months or so, the batteries were completely discharged and damaged... Likely there won't be any protection between the battery and spot welder contacts and FETs, but the rest of the circuit could be connected through proper undervoltage (and also overcurrent - for charging) protections (but with these kinds of devices, you never know of course...). Reading the description on Ali of your welder now, it does claim 2.5year theoretical standby time and only 20μA standby current, and it talks about "Over-current short-circuit protection" (and even "Overcurrent protection: 1.12KA" suggesting that the welding output is also current limited and/or protected) and "low current protection" (maybe that is undervoltage protection)? Any evidence of these protections on the PCB?
Do you think the firmware could be extended to accept an external trigger? I have the same unit, and would love to be able to have a footpedal. Maybe those contacts at the bottom of the main pcb could be used.
@@atc1441 I really enjoyed your disassembling video very much, yesterday... I have gone through IDA myself for something i needed to change in a commercial thing, but it was quite nice to see how others than me go at a problem to finally find the right bits and bytes. Awesome!
Looks like you could wire the LCD in and rotate it to face the way you want. But then the controls might be reversed. Definitely have a fire pan near by if you use that thing on lithium batteries.
There's another review at ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-XXuvlVmbcb0.html but not nearly as coherent. That seems to be an older model - the display is less colourful and it has some maker's / seller's name information on the panel.
Welding seems to be working well enough. I just always wonder how long the lithium battery survive those high current draws? More expensive kits work with a big amount of capacitors, and I guess it has a reason?
I doubt it is a big problem, since the pulse is just so short. I would love if it had a 18650 cell though, so you could replace it with a beefy one that can output 35A without problems.
From my experience with two similar types of welders, the internal Lipo cell lasts long enough to make a video, and maybe spot weld one battery. Both of mine were no good a month later. Battery lost its capacity. The units weren't that powerful anyway, not worth replacing the cells.