CR123A Battery Guide: Sizes, Capacities and Uses

CR123A is one of the most widely used primary lithium cells in the world. It is a cylindrical 3V cell built on lithium manganese dioxide chemistry, known in the source catalogue as CR17345, with a diameter of 17.0 mm and a height of 34.5 mm and a reference weight of 16 g. It powers cameras, security equipment, medical devices, torches and industrial instruments — anywhere a compact 3V cell with a long shelf life is needed.

Size and naming

The name CR123A is a consumer label; the industrial designation CR17345 describes the size directly: 17 mm diameter, 34.5 mm height. A related but different cell is CR2, designated CR15H270, at 15.6 by 27.0 mm. The two are not interchangeable, and neither is interchangeable with a rechargeable RCR123A cell, which delivers a different voltage and must not be substituted without checking the device's requirements. When ordering, use the industrial designation as well as the consumer name to avoid size errors.

Capacity variants

The source specification table lists four capacity variants for CR123A: 1,500, 1,600, 1,700 and 2,100 mAh. That range exists because capacity depends on discharge conditions: the current drawn, the cut-off voltage and the test temperature all affect the measured figure. A cell rated at 2,100 mAh under light load will deliver less under heavy load, and the honest way to compare variants is to read them with their test conditions, not as bare numbers. This site lists all four variants and does not present any single variant as the capacity of the model.

Standard discharge current, cut-off voltage and test temperature are table values from the source specification table for this model. Those conditions should be read alongside the capacity figure whenever a variant is selected for a device with a demanding load profile.

Typical uses

Cameras and imaging accessories were the original mass market for CR123A, and they remain a major use: film cameras, flashes and accessories that need a compact 3V supply. Security equipment is another: wireless sensors, alarm components and access devices that must work on demand after long periods of standby. Medical devices use CR123A where a compact, reliable 3V supply matters. Torches and portable lights use it where high output from a small cell is needed. Industrial instruments use it where a long shelf life matters more than rechargeability.

The LiMnO2 line is stated to offer a shelf life of up to 10 years, with self-discharge of less than 1 percent per year at 20 degrees Celsius, and a category temperature range from -40 to 85 degrees Celsius. Those figures explain why CR123A is stocked as a spare and installed in devices that may sit unused for months: the cell is ready when the device is needed.

CR123A in packs

CR123A cells are also assembled into custom packs. The company's own published case example, reported as a company statement, describes a custom CR123A pack built for a home fire and water-damage protection system in North America, in 1S6P and 6S1P structures at 18V and 9Ah. No customer name is given in that example, and none is given here. Packs combine cells in series for voltage and in parallel for capacity, and pack specifications are confirmed per order.

Buying guidance

When buying CR123A cells, confirm the capacity variant, the quantity, the operating temperature range and the final datasheet. Be wary of any listing that quotes a single capacity figure without test conditions, and do not substitute rechargeable equivalents without checking voltage. Minimum order value is USD $500, according to the company FAQ, and samples are available. Lead time is confirmed per order. Certificates are available upon request.

Related pages: CR123A (CR17345), LiMnO2 Batteries, CR2, Batteries for Alarm Systems.

The wider CR cylindrical family

CR123A sits inside a wider CR cylindrical family that shares the same 3V lithium manganese dioxide chemistry and the same handling rules, differing only in size and capacity. CR2, designated CR15H270, is smaller at 15.6 by 27.0 mm, with 850 or 1,000 mAh in two variants and a reference weight of 11 g. CR14505 is a longer cell at 14.5 by 50.5 mm and 1,400 mAh, with a reference weight of 17 g. CR26500 is a larger cell at 26.5 by 50.5 mm and 5,400 mAh, with a reference weight of 62 g. CR34615 is the largest in the model pages on this site, at 34 by 61.5 mm and 12,000 mAh, with a reference weight of 125 g. Other models in the source table include CR17335, CR14250, CR14335, CR17450, CR17505, CR18505, CR11108, CR-V3 at 6V, CR9V at 9V, CR-P2 at 6V and 2CR5 at 6V. Keeping one chemistry across a product family simplifies qualification and stocking, because the voltage, the storage rules and the certification names stay the same while only the size and capacity change.

The practical consequence is that a product family can standardise on LiMnO2 and still cover a wide span of devices: a compact camera accessory on CR2, a security sensor on CR123A, a medical instrument on CR14505, and a long-life industrial installation on CR26500 or CR34615. When a new device is added to the family, the first question is which existing CR size fits its compartment and energy budget, rather than which new chemistry to qualify.

Storage, safety and disposal

CR123A cells should be stored cool and dry, in their original packaging or in trays that prevent terminals from touching each other or metal objects. A short circuit during storage can damage a cell and create a safety hazard, so damaged packaging should be checked before use. Cells that are swollen, leaking or physically damaged should not be installed. Used lithium cells should be disposed of through the proper channel for lithium cells, not in household waste, and local rules for lithium disposal should be checked, because they differ by region. For transport, UN38.3 test documentation applies to the cell design, and shipping arrangements are confirmed per order, with air freight or sea freight stated as the available options. Rechargeable equivalents must not be substituted without checking voltage: a rechargeable RCR123A cell delivers a different voltage from a primary CR123A cell, and the device's requirements decide whether that substitution is safe.

For a buyer new to CR123A, the practical next step is a sample order: cells of the capacity variant that matches the device's load, tested in the device itself under realistic conditions. Samples are available, minimum order value is USD $500 according to the company FAQ, and lead time is confirmed per order. A sample test answers the questions no catalogue can: the real voltage under load, the real capacity at the device's discharge rate, and the real fit in the compartment. Once the sample passes, the bulk order is a formality rather than a gamble.