Lithium cylinder
CR123A
BuyCR123ALithium · 3 V · 17.0 × 34.5 mm
Safe swap, same cell: 123 · CR17345 · EL123AP · RL123A · K123LA
3 V · 17 × 34.5 mm · Lithium manganese dioxide cylinder
CR123A is the 3 V lithium/manganese dioxide cylinder Energizer sells as 123 (EL123AP). The sheet prints ANSI-5018LC, IEC-CR17345, 1500 mAh to 2.0 V on 100 Ω at 21°C. The drawing marks 17.00 mm and 34.50 mm as maximums. It is one cell at 3 V. A23 is 12 V alkaline and will not do this job, and this cell will not do A23's.
| Chemistry | Lithium manganese dioxide cylinder |
|---|---|
| Nominal voltage | 3 V |
| Diameter × height | 17 × 34.5 mm Energizer 123 drawing marks 17.00 mm and 34.50 mm as maximums. The IEC designation on the sheet is CR17345. |
| Designation on the datasheet | ANSI-5018LC, IEC-CR17345 |
| Weight | Energizer 16.5 grams (0.58 oz.) |
Can I substitute it?
Not a CR2, not a 2CR5, not an A23. Match CR123A / 123 / CR17345. Rechargeable cells of a similar diameter are a different product and are not listed here.
Size check at real size
Lay the old cell on the outline. This shows the top outline (diameter) and the side outline (height) at 1:1 once the screen is calibrated.
CR123A outline, 17 × 34.5 mm. Not a photograph, drawn from the figures above.
Calibrate this screen
Screens scale pages differently, so true size is only true after calibration. Hold a bank card or ID card (85.60 mm wide, ISO/IEC 7810 ID-1) against the bar and slide until the bar is exactly as wide as the card.
Saved in this browser only.
All cells on one true-size sheet
When printing, set scale to 100% or Actual size, not Fit to page.
Capacity
| Source | mAh | Test as printed |
|---|---|---|
| Energizer | 1500 | to 2.0 volts; rated at 100 ohms at 21°C |
Cross-reference
Each code is printed on the cited chart. A shared outline is not, by itself, the same cell.
| Where it is printed | Code |
|---|---|
| Listed label | CR17345 |
| Listed label | EL123AP |
| Listed label | RL123A |
| Listed label | K123LA |
Devices named on the Energizer guide
Photo, laser sights, security cameras, connected home devices, flashlights. See cameras and photo, smart-home sensors, flashlights and lasers.
Small lithium cylinders and camera packs
CR123A, CR2, CR-P2 and 2CR5 are lithium/manganese dioxide, the same chemistry as a CR coin, in a different can. Energizer 123 is the CR123A type: the sheet prints IEC-CR17345, ANSI-5018LC, nominal 3.0 V, and 1500 mAh to 2.0 V on 100 Ω at 21°C. The drawing's maximums include 17.00 mm and 34.50 mm. It is a single 3 V cell. It is not an AA, and it is not the 12 V A23, which is a stack of alkaline button cells in a thinner tube.
CR-P2 (Energizer 223) and 2CR5 are 6 V packs used in cameras and some fobs. Each Energizer sheet rates 1500 mAh. The cutoff on the CR-P2 sheet is 4.0 V; on the 2CR5 sheet it is 2.0 V. Same milliamp-hour headline, different test. The cans are prismatic. A diameter-and-height search does not apply, and the pages say so.
CR2 is on Energizer's replacement guide (cell size 1CR2, labels CR2, RLCR2, KCR2, photo and connected-home devices). A product datasheet for it was not available at the URLs we tried, so voltage, capacity and millimetres are left blank rather than filled in from memory.
Sources
Last verified 2026-10-29.
- Energizer battery cross reference guide Energizer, checked 2026-10-29
- Energizer 123 product datasheet (123.pdf) Energizer, checked 2026-10-29