Electronics and technology blog    /    Materials for 30.01.2026

Last fall, I had a small order lined up to build a clever UPS, but the order was eventually canceled. The power supply I’d bought for it, though, was still here. I finally found a little time to test it, and I think this will be useful for anyone planning to buy one like it.

Continuing the previous comprehensive review, this time with a pair of 21700 batteries: one is geared more toward high current, the other toward high capacity.