Aliexpress spot welders?

[TheGaben]

Anyone have any expirience with the aliexpress welders with integrated lipo packs like this one?
https://www.aliexpress.us/item/3256802322608062.html?spm=a2g0o.productlist.main.17.46c67425iqOC1U&algo_pvid=3d4189ed-2246-4470-9d27-c8928e9b5ea0&algo_exp_id=3d4189ed-2246-4470-9d27-c8928e9b5ea0-8&pdp_ext_f=%7B%22sku_id%22%3A%2212000031234073494%22%7D&pdp_npi=2%40dis%21USD%2187.4%2144.57%21%21%21%21%21%4021021f7b16741782802865234d0687%2112000031234073494%21sea&curPageLogUid=EElRqdqutzvk

 

[scianiac]

I have one of the similarly cheap but without integrated battery versions (well two but that's because I damaged the display on one but that was my own fault) and I will say so far with my limited use it's been fine but longevity of these units compared to more expensive versions may not be amazing. At least the ones I have and others I've seen have no protection at all, just a rack of big mosfets, no flyback diodes or TVS anywhere which works fine but eventually, depending on how much power you use and how long/close together the leads are those mosfets will become unhappy. Having the battery in the unit at least means the battery leads are very short though. Who knows the quality of that battery though. I just like messing around with things so I'm just adding said protection devices along with heavier bus bars.

 

[docw009]

I started with an integrated welder. They're powered by internal lipo pouch cells with a high C (discharge) rate. As the cells age, they lose their high discharge capability, and this is hastened by storing them near full charge.After about 8 weeks, mine quit working. It still pretended to weld, but the nickel wouldn't melt.

So I bought this $20 red welder. It's somewhat notorious on youtube for needing user fixes unless you run it on a high discharge lipo battery, but I beefed it up to work OK on a car battery, However, it works better with a RC lipo hobby pack, 11.1V 5Ah with a C rate of 70-140, so it can pulse 500-500 amps. These cost about $50 and need a RC hobby charger to safely charge them, which is also about $50.

To maintain the lifetime of the battery, they want you to discharge it to 50% for storage, The hobby charger can do that. The red welder will do .15mm nickel reasonably well.


Recently, I bought this welder, about $20. It can pass a higher current and welds ,15 nickel more easily. I believe it can do a nickel -copper sandwich, which is why I bought it. Initial tests says it can.


If you get serious about this, you should buy a K-weld, for $200-250 and a power supply for $100-150. I'm not that serious.