Here's How To Tell If A CR2032 Battery Is Bad

We may receive a commission on purchases made from links.

If you've had to replace the battery in an Apple AirTag, you've seen a CR2032 battery up close. The performance of the 3-volt CR2032 lithium battery is somewhat of a double edged sword for consumers. While no battery lasts forever, the CR2032 provides relatively level usable voltage for the majority of its lifespan before it crashes to unusable levels with little warning.

Your car's key fob may also use a CR2032 battery, and if you're lucky, you may be able to spot a dying key fob battery before it's too late. However, in some cases the fob might not work as well as it used to, or not at all, even though the battery still has life left in it.

Whether you want to check the voltage of that button cell battery you found in your drawer, or the battery in your key fob that suddenly stopped working, there are a couple of easy options. The easiest method to tell if a CR2032 battery is bad is to use a battery tester like the LaCrosse 911-65557-INT, available through Amazon for $15.99. Another option is the slightly more expensive Amazon's Choice Dlyfull universal battery checker priced at $18.99, unless it's on sale. Either unit clearly displays the status of CR2032 batteries, along with a number of other popular battery sizes and types.

If you never plan on expanding your electrical testing repertoire beyond checking whether batteries are good or bad, or if you just prefer simple no-nonsense testers, you probably don't need a multimeter. However, beyond checking disposable battery voltages, there are some handy uses for a multimeter around the home and garage.

To use a multimeter to test the voltage of a CR2032 battery, you'll need a meter that measures DC (direct current) voltage. While some high-end multimeters can cost hundreds of dollars, most DIYers are served well by meters costing a fraction of that. However, be prepared to spend a little more than it costs to buy one of the battery testers we mentioned earlier.

One good option is the MM325 manual-ranging digital multimeter from Klein Tools. It's priced at $34.97, or around $30 if you catch it on sale on Amazon, and it holds a 4.7-star rating with over 2,000 reviews to date. The MM325 is capable of measuring AC and DC voltages up to 600V, 10 amp DC currents, and 2 megaohms of resistance. It also has functions to test continuity, diodes, and batteries. The battery test function on the Klein Tools MM325 is only designed to work with 1.5V and 9V batteries, but you can use the 20V DC setting to measure voltage of a 3V CR2032.

With the MM325 selector set to 20V DC, touch the meter's red lead to the positive side of the battery and the black lead to the negative side. New CR2032 batteries have a nominal voltage of 3V, often measuring up to 3.3V. CR2032 batteries with voltages between 2.7V and 2.9V are still usable, while readings below 2.7V indicate the end of its life.