Half Power Bank, Half Spot Welder

There was a time when every gizmo on AliExpress also had a big white LED so it could also work as a flashlight, but maybe the power bank is the new flashlight. [Aaron Christophel] has a battery spot welder that costs a not unreasonable 30 euros and can also be used as a novelty power bank. He subjects it to a test and teardown in the video below the break.

First of all, he conducts a few weld tests, and we have to say it seems capable of some reasonable results if its parameters are correctly adjusted. Then the end comes off the extruded aluminium case, and the guts of the device are slid out for a teardown.

The power comes from a pair of Li-Po pouch cells, while on the board, there’s an STM32 clone providing the timing for a set of MOSFETs that do the heavy lifting. There’s a colour display for tweaking the settings. Alongside all this, there’s also a small chip for that power bank functionality. Charging is via USB-C, though, of course, it’s not really proper USB-C but a USB-C socket that expects 5 volts. This is a disappointing trend in cheap electronics that sullys the promise of USB-C.

It seems this spot welder is capable of doing the job, which is pleasing after our previous disappointing look at battery welders.

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Review: Battery Spot Welders, Why You Should Buy A Proper Spot Welder

Making battery packs is a common pursuit in our community, involving spot-welding nickel strips to the terminals on individual cells. Many a pack has been made in this way, using reclaimed 18650 cells taken from discarded laptops. Commercial battery spot welders do a good job but have a huge inrush current and aren’t cheap, so it’s not uncommon to see improvised solutions such as rewound transformers taken out of microwave ovens. There’s another possibility though, in the form of cheap modules that promise the same results using a battery pack as a power supply.

With a love of putting the cheaper end of the global electronic marketplace through its paces for the entertainment of Hackaday readers I couldn’t resist, so I parted with £15 (about $20), for a “Mini Spot Welder”, and sat down to wait for the mailman to bring me the usual anonymous grey package.

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