CR2 and CR123A batteries are both 3V lithium manganese dioxide (Li-MnO₂) single-cell batteries, but they differ significantly in physical dimensions and application compatibility. CR2 (15.6mm diameter × 27mm height) is smaller than CR123A (17mm × 34.5mm), making them incompatible in devices requiring specific battery compartment sizes. Both are non-rechargeable and optimized for high-drain devices like cameras and flashlights, though CR123A’s larger size often correlates with higher capacity and extended runtime.
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What are the key dimensional differences?
CR2 batteries (model CR15266) measure 15.6mm × 27mm, while CR123A (CR17335) measures 17mm × 34.5mm. The 1.4mm wider diameter and 7.5mm greater height of CR123A prevent cross-device compatibility despite identical voltage.
These size variations directly impact device design. For instance, CR2’s compact form suits slim gadgets like laser pointers, whereas CR123A’s larger build accommodates higher energy storage for power-hungry equipment like tactical flashlights. Pro Tip: Always verify battery compartment dimensions before purchasing replacements—using CR2 in a CR123A slot risks poor contact and malfunction.
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How do their model numbers relate to specifications?
Battery nomenclature encodes size: CR15266 (CR2) breaks down to 15mm diameter and 26.6mm height, while CR17335 (CR123A) denotes 17mm diameter and 33.5mm height. The “CR” prefix indicates lithium manganese dioxide chemistry.
This coding system helps professionals quickly identify replacements. For example, security camera manufacturers might specify CR17335 batteries for their extended runtime, leveraging the larger size’s capacity advantage. But why does this matter? Misreading model numbers could lead to purchasing CR2 batteries for devices needing CR123A, resulting in premature power loss.
| Feature | CR2 | CR123A |
|---|---|---|
| IEC Code | CR15266 | CR17335 |
| Capacity Range | 750-850mAh | 1400-1600mAh |
Are there capacity differences between them?
CR123A typically offers double the capacity of CR2—1,500mAh vs 800mAh—due to its larger volume. This makes CR123A preferable for devices requiring sustained high-current output.
Digital cameras demonstrate this distinction clearly. A CR2-powered camera might last through 200 shots, while CR123A could deliver 400+ shots. However, capacity varies by brand—premium CR123A cells like Panasonic’s Lithium Pro pack 1,700mAh. Pro Tip: For critical applications, prioritize name-brand batteries with certified capacity ratings.
What applications typically use each battery?
CR2 batteries dominate compact electronics: LED penlights, laser levels, and glucose monitors. CR123A powers demanding devices like weapon lights, digital SLRs, and home security systems requiring extended operation.
Fire alarm panels often use CR123A for its decade-long shelf life—essential for emergency systems. Conversely, CR2’s smaller profile fits medical devices where space constraints exist. But what if your device accepts both? Always follow manufacturer specifications—heat dissipation and current requirements differ even if voltages match.
| Device Type | CR2 | CR123A |
|---|---|---|
| Medical Equipment | ★ Common | Rare |
| Tactical Gear | Rare | ★ Standard |
Battery Expert Insight
FAQs
Not recommended—voltage sag under load differs due to capacity variations. Spacer hacks risk incomplete circuit connections and device damage.
Do CR123A batteries last longer than CR2?
Yes, typically 2× longer in comparable devices due to doubled capacity. However, runtime depends on discharge rate—high-current devices reduce this advantage.
Are rechargeable versions available?
Yes—some manufacturers offer 3.2V LiFePO4 CR123A (16340 size), but they require specific chargers and aren’t direct replacements for 3V lithium cells.