Okay, so I've been through SO many button cell batteries for my random gadgets – from cat laser toys to digital calipers – and these LiCB ones? Total game-changer.

First off, 40 batteries for this price is insane. I used to buy these in overpriced 4-packs at drugstores. Not anymore! Popped one into my caliper and it worked instantly – no weird 'low battery' warnings like some cheap brands.

The real test? My demon... I mean, my cat's laser pointer. These lasted WEEKS with daily play sessions. The Christmas decorations test another reviewer mentioned? Can confirm – left some LED snowflakes running 24/7 and they just wouldn't die.

No leaks, no duds in the pack (I checked like five randomly because trust issues). Came in perfect blister packaging that makes storage easy. Shelf life seems legit too – stored some spares for months and they worked fine when needed.

Pro tip: If your device takes any of those million battery codes listed (AG13, 357, etc.), these will work. Saved me from buying 'specialty' batteries at triple the price. Already reordered!