We’re working on a project that has a battery backup, but we don’t have any more coin cell holders on hand. No problem, we remember seeing a double pin header used for this. But when we… ...

The two coin cells were in their own somewhat “elegant” removable holder in a pocket away from the PC board, and connected to the board by a pair of modest-gauge wires so they are somewhat independent ...

The Coin Cell Emulator CR2016/CR2032 by [bobricius] ... It integrates a micro USB connector with a 3V regulator for using USB as an external power source.

BTW, according to my vernier calipers, the 4.5 V AR18 coin cell measures 18.8 mm thick, 23.3 mm in diameter, and has a crimped seam around the middle with a 25.1 mm diameter, in case you are curious ...