CR2032 Battery holder with no need for soldering.
Personally the 1.2mm holes works really well with the 0.8mm wire i'm using.
Only tested on CR-10S, but should work fine on any printer.
Works best if you put bottom wire on one side, and top wire on the other.
15-03-2024 update: Added hole at the “bottom” to be able to push out the battery easily.