CR123 and CR2 batteries are both 3V lithium cells but differ in size and capacity. CR123 (17mm x 34.5mm) offers higher energy storage (≈1500mAh) for high-drain devices like tactical flashlights. CR2 (15mm x 27mm) suits compact gear like cameras, with ≈800mAh capacity. Never substitute without verifying device compatibility—size mismatch risks poor contact or damage.
CR123 vs CR123A Batteries: What Are The Key Differences?
What are the physical differences between CR123 and CR2 batteries?
CR123 batteries measure 17mm in diameter and 34.5mm in length, while CR2 cells are smaller at 15mm x 27mm. This size variance impacts device compatibility—CR123’s larger form factor suits high-power applications, whereas CR2 fits space-constrained gadgets. Weight also differs, with CR123 averaging 17g vs. CR2’s 11g.
Beyond dimensions, CR123’s greater volume allows higher energy storage (1500mAh vs. CR2’s 800mAh). For example, a security camera using CR123 might run for 30 hours, while a CR2-powered laser pointer lasts 15 hours. Pro Tip: Use calipers to verify battery compartments—forcing a CR123 into a CR2 slot can bend terminals. Transitional note: While voltage is identical, capacity and size dictate application-specific use.
| Parameter | CR123 | CR2 |
|---|---|---|
| Diameter | 17mm | 15mm |
| Length | 34.5mm | 27mm |
| Weight | 17g | 11g |
How do voltage and capacity compare between CR123 and CR2?
Both deliver 3V nominal voltage, but CR123’s larger size provides ≈90% more capacity. A CR123 typically offers 1500mAh, whereas CR2 ranges from 750–800mAh. This makes CR123 ideal for high-drain devices like digital cameras during extended shoots. Why does capacity matter? A trail camera using CR123 might last a week, while CR2 versions require twice the replacements.
Practically speaking, CR123’s energy density (~260Wh/kg) outperforms CR2’s ~218Wh/kg due to optimized internal structures. Transitional note: However, capacity isn’t the sole factor—CR2’s compactness is irreplaceable in devices like penlights. Pro Tip: For low-drain gadgets (e.g., thermometers), CR2’s lower capacity is offset by its size advantage.
Which devices commonly use CR123 vs. CR2 batteries?
CR123 powers high-demand gear: weapon lights, industrial sensors, and medical devices. CR2 excels in compact tech: handheld calculators, bike lights, and laser pointers. For example, professional photographers often use CR123 in external flashes for rapid recycle times, while CR2 fits slim remote controls. Transitional note: What if a device accepts both? Manufacturers rarely design dual compatibility due to size constraints.
Can CR123 and CR2 batteries be interchanged?
Despite matching voltage, physical differences prevent safe interchangeability. CR123’s 7.5mm extra length and 2mm wider diameter disrupt compartment fit. Hypothetically, could spacers work? Yes, but uneven pressure may damage contacts. A real-world analogy: Using a CR2 in a CR123 slot is like putting a AAA in a AA slot—it’ll rattle and lose connection.
| Scenario | Risk Level | Outcome |
|---|---|---|
| CR2 in CR123 slot | High | Intermittent power, device damage |
| CR123 in CR2 slot | Critical | Jammed battery, terminal deformation |
Pro Tip: Label battery compartments with model numbers to avoid mix-ups during replacements.
What Battery Can Replace CR123A?
Redway Battery Expert Insight
FAQs
Yes, Li-ion equivalents like 16340 (CR123) or 15270 (CR2) exist, but verify voltage compatibility—3.7V rechargeables may require circuitry adjustments.
Are CR123A and CR123 the same?
Yes, “CR123A” is a redundant designation—both terms refer to the same 3V lithium battery size and chemistry.
Do CR2 batteries expire?
Unused CR2 cells retain 85% charge for 10 years due to lithium’s low self-discharge rate (≈1% annually).



