EEMB 5PCS LIR2450 Rechargeable Battery 120mah 3.7V Lithium-ion Coin Button Cell Batteries with Solder Tabs

Gave a new lease of life to some older items, at reasonable cost, restoring original functionality to some wind-up emergency flashlights which were otherwise close to useless.

Had a very frustrating experience with NIX support trying to resolve an issue with my sensor (2 yrs old, used 3 times, now dead). I was pretty sure it was a failed battery (it will not run with an external battery) but they offered no help other than a link to their store. Frustrated, I cracked it open ("pinched" it gently with a bench vise) and found this battery. Ordered a few of them and with a little soldering, brought my sensor back to life!

With a small area to build in electronics, this battery was a project saver.. A few mods to the sword of omen, and was able to bring the sword to light.

I bought these to replace a couple of batteries in two non-working crank-rechargeable flashlight and flashlight/radios. They came with an apparently full charge on them and now, six months later, they are both still working as-designed in their respective portable crank-up units. The units' original batteries had failed through lack of use and periodic recharging; something to keep in mind if you own such devices. The repaired dedicated flashlight works so well that I have moved it over to a daily use item. The flashlight/radio that was repaired gets cranked up and tested once a month. So far, so good. These batteries can be used in other projects as well, but for me the flashlight and radio functions are fine.