The dimensions of a CR123 battery are approximately 34 mm in length and 16.5 mm in diameter
Length: 33.4 mm to 34.5 mm
Diameter: 16.5 mm to 17 mm
CR123A batteries, have very similar dimensions, with slight variations:
- Length: 33.4 mm to 34.4 mm
- Diameter: 17 mm
Here’s an interesting deep dive:
CR123A and rechargeable substitutes
Near the end of the article is the 3xCR123 substitute options.