Electronics and technology blog    /    Materials for January 2026 year

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.

Not long ago, one of my readers got in touch again and asked me to test some batteries. Why not? I find it interesting, and it’s useful for you, so I agreed. Today is part one: 18650 cells from the same manufacturer, the well-known EVE.