CR123A vs CR2
Both are 3V lithium primary cylinders used in cameras, sensors, and specialty lights — but CR123A (~17 × 34.5 mm) is larger and higher capacity than CR2 (~15.6 × 27 mm). They are not drop-in replacements for each other.
Last verified Aug 25, 2026
Not interchangeable — match the exact code on the device or old cell.
A CR2 vs CR123A swap fails on diameter, thickness, capacity. If the door only closes when you force it, or the device works only while you press the cover, you have the wrong cell — not a weak spring you should ignore.
They share 3 V and LiMnO2, which is why CR123A vs CR2 looks interchangeable on a store shelf. Highlighted rows are the ones that change the purchase: diameter, thickness, capacity.
Read physical fit before capacity. Extra milliamp-hours only help when the holder is built for that cell. A “better” spec in the wrong tray is a mechanical or voltage mismatch, not an upgrade.
If you searched CR2 vs CR123A, you are on the same comparison with the names reversed. The difference between CR123A and CR2 batteries is not the word “vs” — it is the specs that do not match after you ignore the similar photos.
CR123A is 17 mm across; CR2 is 15.6 mm. That gap is enough for one cell to miss the clip entirely or rattle in the other tray. IEC codes put diameter in the first digits for a reason: you cannot sand a coin cell down to fit.
CR123A is 34.5 mm thick; CR2 is 27 mm. Holders are built for one stack height. The thinner cell loses spring pressure (“works only when I press the cover”). The thicker cell jams the door or bends the clip.
Typical CR123A capacity is 1400–1600 mAh. CR2 is 750–850 mAh. Runtime only follows that gap inside the correct holder. Extra capacity in the wrong tray does not last longer — it often does not run at all.
Shared 3V Li-MnO2 chemistry class — different physical size
CR123A ~17 × 34.5 mm vs CR2 ~15.6 × 27 mm
CR123A typically ~1400–1600 mAh; CR2 ~750–850 mAh
Device tubes, springs, and doors are sized for one format
Coin and button codes are rulers, not brand slogans. The letters mark chemistry class. The digits encode size. CR123A measures 17 × 34.5 mm; CR2 measures 15.6 × 27 mm. Once you read the code that way, CR2 vs CR123A stops looking like a preference and starts looking like a fit check.
Usually no. CR123A is 17 × 34.5 mm at 3 V (LiMnO2). CR2 is 15.6 × 27 mm at 3 V (LiMnO2). Those are not the same part.
If the spent cell or tray said CR2, specify that code. Forcing CR123A can crack a cover, lose contact, or apply the wrong voltage.
Usually no. Going the other way does not fix a diameter, thickness, or voltage miss. CR2 in a CR123A holder has the same problem with the names flipped.
If you arrived from a CR2 vs CR123A search, stay on this page. The answer does not change.
Retail packs hide the IEC size behind house codes. CR123A also appears as CR17345, DL123A, EL123A. CR2 also appears as DLCR2, EL1CR2. Those prefixes do not change the outline unless the chemistry letters change (BR, LIR, ML, PR).
You do not need a full datasheet to settle CR123A vs CR2. You need the stamp, the tray, or a cheap pair of calipers. A store bin labeled only “button cell” or “3V lithium” will not do that work for you.
Do not force a CR123A into a CR2 compartment or pad a CR2 into a CR123A tube. RCR123A / RCR2 rechargeables are separate products — only use them when the manual allows.
Do not stack cells, grind a can, or use foil as a permanent spacer to fake CR2 with CR123A. Read the stamp, then the spec table. If the door will not close without force, you have the wrong height or diameter.
No. CR2 is shorter and narrower with lower capacity. It will not seat reliably in a CR123A holder.
Yes — both are typically 3V lithium primary cells. Voltage alone does not make them interchangeable; size still has to match.
In the correct host, CR123A usually offers more capacity. Runtime still depends on device drain and temperature.
Yes. CR123A vs CR2 and CR2 vs CR123A are the same pair. Fit, voltage, and chemistry do not change when you flip the order.
Use this guide as a starting point, then confirm voltage, chemistry, and physical size with your device manual or the marking on the old cell.
Reviewed by PlainBattery Technical Review Desk on 2026-08-25. Checked: both model identities and dimensions, voltage and chemistry differences, physical fit, interchangeability conclusion and safety warnings.
Revision record: source citations and field-level review scope added September 11, 2026. See our sources and methodology and corrections policy.
