UniEnergy Technologies Battery » What Is A CR123A Battery? (Basics & Comparisons)

What Is A CR123A Battery? (Basics & Comparisons)

Batteries come in various shapes, sizes, and even compositions that allow you to use them in certain applications. Understanding these differences ensures you use the right batteries for your valuable electronics, and it can help you make a better choice in power supply.

While CR123A batteries are a popular type of battery and easy to find, there are some key differences that set them apart from other types of batteries. These affect best use, and using the wrong battery can even lead to disaster.

In this article, we explain the basics behind CR123A batteries and compare them to similar batteries.

CR123A Battery Basics

When you’re looking at batteries, there are a few key characteristics that help you distinguish them from other battery types.

For CR123A batteries, we’ll look at:

  • Size
  • Nominal voltage
  • Capacity
  • Chemical composition
  • Shelf life

These affect what type of devices and systems these batteries work best in and help you separate them from similar batteries.

Size and Appearance

Different size batteries are the most obvious indication of differing specifications.

CR123A batteries have a cylindrical shape with the following dimensions:

  • 17 mm (0.67 in) diameter
  • 34.5 mm (1.36 in) length

They’re slightly thicker and shorter than popular AA (14.5 mm x 50.5 mm) or AAA (10.5 mm x 44.5 mm) batteries. Similarly, they have different labels depending on the brand of the battery (i.e. Energizer batteries are usually white with blue writing).

Most CR123A batteries come in even sets, ranging from 2 to bulk sets of 12 or more.

Nominal Voltage

CR123A batteries have a nominal voltage of 3.0 volts.

This number refers to the voltage at which the battery is intended to use, and it may differ from the actual voltage of the battery. While most CR123A batteries should test around this number, it may be a bit higher or lower (especially with cousin battery types).

The voltage also differs depending on the condition of the battery (but more on that later).


The capacity of a CR123A battery is around 1,500 mAh. Battery capacity is measured in Amp hours, and it refers to what discharge current of the battery could be drawn for an hour.

Keep in mind that this is a general capacity. While voltage is a standard of the battery type, capacity changes depending on the quality of the battery (usually when switching brands) and its condition.

Similar battery types may have smaller or larger capacities.

Chemical Composition

CR123A batteries are lithium manganese dioxide (LiMnO2) batteries. Not all li-ion batteries should be lumped together, but they share some characteristics with other lithium batteries.

CR123A batteries use lithium as the anode, and then a liquid electrolyte with manganese dioxide as a solid cathode.

This combination provides a lightweight composition and powerful battery technology. They’re incredibly energy dense, reliable, and have higher potential over a greater temperature range.

Shelf Life and Usage Life

The shelf life of a CR123A battery is different from its expected usage length (which relates to the capacity of the battery.

Most CR123A batteries can sit on a shelf for 10 years before you need to use them up. This is why they’re a common choice for emergency equipment, such as flashlights, that you may not use on a regular basis.

Their lifespan while in use depends on the battery’s capacity, the nature of the work, and how often they’re used. For example, a weapon light used regularly for training may not break a month, while a security system panel can run off the battery for over a year without issue.

Most Common Applications

Most Common Applications
Image credit: bestbuy.com


CR123A batteries are used in plenty of small electronic devices, such as:

While any small device may call for them, their reliable performance and high capacity make them integral to the operation of security equipment, including security alarm systems, that operate on wireless networks.

They’re not expensive, but they’re an excellent choice for professional photography equipment or any other higher-tier needs. You’ll see these batteries used often for emergency equipment because of their durable nature, capacity, and preferred voltage.


CR123A batteries carry the same safety concerns as all other batteries.

They should not be damaged or disassembled, and such batteries should be discarded. Any changes in battery structure affect the operation and can lead to high temperatures or short circuits that may evolve into fires.

More advanced designs, such as rechargeable models, usually have small electron circuits in them that increase the safety of the battery and prevent these issues and more. This contributes to their lower capacity, but it’s an essential trade off.

Is There a Difference Between CR123A and CR123 Batteries?

You may see CR123 battery labels instead of CR123A. The lack of the letter “A” doesn’t change the battery specifications. Some manufacturers simply drop the letter at the end, but they’re exactly the same.

Other names you may see include:

  • CR17345
  • K123A
  • RCR16340
  • VL123A
  • DL123A
  • 5017LC
  • SF123A
  • EL123AP
  • 17345
  • 17340
  • 16340

It’s suggested you double or even triple check your battery choice before swapping to a different name. The letter and number combinations are easy to mix up, so verify voltage before installing and using your battery.

CR123A vs. RCR123A Batteries

One battery that appears similar to CR123A batteries but is slightly different are the rechargeable RCR123A batteries. While they are intended as a rechargeable replacement, there are enough differences to matter.

Details such as voltage, capacity, and shelf life affect how they can be used. In some cases, the rechargeable option may damage your device or prove inefficient compared to a standard CR123A battery.


Non-rechargeable CR123A batteries have a lower nominal voltage than the rechargeable variety. The difference isn’t that great (RCR123A batteries sit around 3.7 volts), but it can be an issue for more sensitive electronic equipment.

It’s important to double check any constraints on your electronics before popping in the higher voltage. Cameras or security equipment may not do well with the difference.


CR123A batteries have a higher capacity than their rechargeable cousins, which hold ½ or ⅓ as much. While high-capacity RCR123A batteries exist, they usually have a lower maximum drain current that affects performance.

The lower capacity allows the rechargeable batteries to accommodate stringent security measures that prevent issues like overcharging or short circuiting.

These batteries focus more on short-term, frequent use. You get more use out of them if you expect to go through the estimated 1,000 to 2,000 charging cycles.

Shelf Life

Rechargeable batteries have a shorter shelf life. They lose anywhere between 10 and 30 percent of their initial charge after a single year of storage, and it only goes down from there.

This may not seem like much, but it’s quite a bit compared to CR123A batteries that still hold strong after a decade in storage. Rechargeable batteries may make sense economically when used consistently, but they aren’t doing any favors hanging out in the reserves.

Initial Charge

RCR123A batteries are also a poor choice for an emergency purchase at the store. They can only be manufactured and transported at half charge, so you need to charge them completely before you use them the first time.

Standard CR123A batteries come at full capacity, so they’re ready to pop in and get to work the moment you wrangle them out of their packaging. This makes them the most reliable operation for emergency power.


Image credit: plasmamusic.com

We’ve already explained the general uses for regular CR123A batteries, and rechargeable batteries can fit in and operate all of those devices. That doesn’t mean they’re well suited for that task.

Rechargeable batteries are better for commonly used devices, such as:

  • Digital cameras (that can handle the voltage)
  • Children’s toys
  • Remote controls
  • Flashlights (regularly used–not emergency lights)

You should avoid them for more integral systems, such as smoke alarms, security systems, or emergency devices. There’s always a chance they’ll drop their charge when you need the device the most, and they’re not a reliable backup.

Where to Buy CR123A Batteries

You can purchase CR123A batteries anywhere you purchase other batteries. The most common places include:

  • Walmart
  • Target
  • Amazon
  • Battery supply stores (i.e. Batteries Plus)

This type of battery is popular enough that it should be readily available on the shelf. Keep in mind if you order them online, you should check reviews to verify the battery is not a counterfeit that may damage your device or provide insufficient voltage.

If buying rechargeable batteries, make sure you use the charger designated for those batteries. Charging performance differs from brand to brand, and you should never attempt to recharge standard batteries.


CR123A batteries are popular for a reason, and many electronics call for this specific battery type for power. You have some similar alternatives to work with, but the difference in chemistry or voltage may make one better or safer than the other.

Make sure you only use CR123A or suitable alternatives in devices that call for them. Using other batteries alongside tin foil or other extenders is not only dangerous but inefficient.

Comment on what you use CR123A batteries for in your daily life!

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