Are CR2032 And CR2025 Batteries Interchangeable?

As a kid, were you ever amazed by how desktop computers magically "remembered" what time it was, even after completely shutting down and powering on several hours later? It almost felt magical how the computer could calculate how long it had been shut down for and display the correct time immediately after booting to the desktop screen. It would only be years later that we would discover that this magic was enabled by a tiny button-sized battery called the CR2032 cell. These batteries supplied a small amount of current to the motherboard (even with the rest of the computer off), powering components such as the Real Time Clock (RTC), CMOS, NVRAM, and BIOS preferences. In reality, the CR2032 cell never let the RTC shut down; it was "on" the whole time.

What is even more incredible is that despite desktop computers having undergone a massive transformation over the past three decades, the use of the humble CR2032 battery has remained unchanged. Besides desktop computers and older laptops, the CR2032 battery is still used in car key fobs, home weighing scales, garage door remotes, small medical devices, and even Apple AirTags.

While the CR2032 battery is pretty well-known among tech enthusiasts, with even laypersons aware of how it looks, what several people do not know is that another battery of a similar type, the CR2025, exists. You may have come across this battery while shopping for a replacement CR2032s and may have wondered whether it is closely related to the CR2032. As it turns out, these two batteries are, indeed, closely related and in many instances, can be used interchangeably — albeit with some caveats

The main difference between the CR2032 and CR2025 batteries is revealed in the name itself. To begin with, the "CR" is not a direct abbreviation. It denotes that the battery is made of Lithium Manganese Dioxide. The first two numbers (in this instance, "20") denote its diameter in millimeters (mm), while the last two numbers is a marker for its thickness. Effectively, a CR2032 is a Lithium Manganese Dioxide battery with a 20mm diameter and 3.2mm thickness, while the CR2025 is just 2.5mm thick. In simpler words, the CR2025 is just a thinner variant of the CR2032 battery.

Being the thinner of the two, the CR2025 is typically used on devices that cannot normally accommodate a CR2032 cell. On the other hand, a CR2025 can be used in devices that support CR2032, though the smaller battery may become loose due to the extra space it leaves within the enclosure. The thicker body of the CR2032 battery also ensures a higher capacity and longer lifespan. A typical CR2032 battery is rated for 235 mAh, while the same for a CR2025 is 170 mAh. Both batteries are rated at 3V, so voltage is not a barrier to interchanging them (only the physical size is).

Both these batteries — the CR2032 and the CR2025 — are extremely affordable and readily available at both online and offline retailers. They generally last a long time, it's easy to tell when they go bad, and do not require frequent repeat purchases. If you came across this article while researching for these, it might be a good idea to check the official spec sheet of the equipment you're planning to purchase the battery for, to ensure that you don't end up buying a thicker CR2032 battery, which may not fit inside an enclosure designed for the CR2025.