Description
H2 Aliexpress link: https://s.click.aliexpress.com/e/_c4FY3IGn
UK3 Aliexpress link: https://s.click.aliexpress.com/e/_c3UNOFqX
H2 Shopee link: https://s.shopee.co.th/20uguUPVze
UK3 Shopee link: https://s.shopee.co.th/6VN6Gu1JLh
I took an old power bank that was nearly 10 years old, ripped out the failed battery and rebuilt it using 18650 lithium-ion cells — while putting two surprisingly powerful portable spot welders through a proper real-world test.
This isn't just another spot-welder review.
I wanted to actually build something with them, hammer them with weld after weld, see how long the batteries lasted and find out whether the tiny AWithZ H2 and larger AWithZ UK3 were genuinely useful or just another gadget.
Along the way I cover:
• Rebuilding an old power bank with 18650 cells
• Connecting lithium cells in parallel
• Why cell voltage matters before connecting cells together
• Mixing different-capacity cells in a parallel pack
• Insulation and avoiding accidental short circuits
• Spot-welding nickel strip onto 18650 cells
• Manual vs automatic triggering
• UK3 foot-pedal operation
• H2 vs UK3 weld performance
• Battery life after a ridiculous number of welds
• The one thing I would change on the UK3
• Preserving the original wireless charging system
The little H2 was the biggest surprise.
I genuinely wasn't expecting much from something so light, but after covering the test material with more welds than any sane person would normally use, it was still showing a full battery and producing excellent welds.
The larger UK3 is the more serious machine and gives you considerably more control, power and the option of a foot pedal — but both machines performed far beyond what I expected.
There is only one significant criticism I could find with the UK3: the welding leads need to be longer.
Other than that, these things pack one hell of a punch.
⚠️ Lithium battery safety: Working with lithium-ion cells involves very high currents and can cause fire or serious injury if cells are shorted, damaged or incorrectly connected. Understand what you're doing before attempting battery modifications yourself.
🔗 AWithZ H2 / UK3 links:
Aliexpress shop - https://www.aliexpress.com/store/1102853625
Official website - https://awithz.net/
If you enjoy practical electronics, battery builds, repairs, 3D printing and the occasional attempt to improve things that probably didn't need improving in the first place, consider subscribing and also, please help me to keep going by joining me on Patreon (with extra content and much more detail) - https://www.patreon.com/vortecks
#18650 #PowerBank #SpotWelder #BatteryBuild #LithiumBattery #DIYElectronics #AWithZ