With the rise of internal, non-replaceable, rechargeable batteries in gadgets like smartphones, we sometimes don’t think about buying new batteries at all. But one type, the coin battery, is a vital means to keep some of our most overlooked but important gadgets going: car key fobs, remote controls, watches and more.
Safety First
Coin batteries are extremely small and very rarely anything but single-use. But they’re also inexpensive and can provide small amounts of power for an exceedingly long time. These batteries can last for a year or more in many situations.
Lasts Nearly Forever
Coin batteries come in several different sizes, and are not interchangeable. So you’ll need to make sure you’re getting the right one. You can go by voltage, but that’s not necessarily reliable. When you pop out your dead battery, look on the underside, and you should see a four-digit code, preceded by some letters, like CR2032. That’s what you should search for to ensure you get what you need.
The specific letters and numbers tell you interesting information about the battery itself. The first letter tells you what the main material is that makes up the battery; “C,” for example, means lithium. The second letter tells you the shape: “R” means “round.” The first two numbers refer to the diameter (in millimeters) and the second two numbers to the battery’s height (in tenths of millimeters). So a CR2032 is a round, lithium-based battery, 20mm in diameter and 3.2mm in height.
