Here’s How To Tell If A CR2032 Battery Is Bad
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If you’ve had to replace the battery in an Apple AirTag, you’ve seen the CR2032 battery up close. The performance of the 3-volt CR2032 lithium battery is like a double-edged sword for consumers. Although no battery lasts forever, the CR2032 provides a standard usable voltage for most of its lifetime before crashing to unusable levels with little warning.
Your car key fob may also use a CR2032 battery, and if you’re lucky, you might be able to spot a dying key fob battery before it’s too late. However, in some cases the fob may not work as it used to, or not work 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 closet, or the battery in your key fob that just stopped working, there are a few easy options. The easiest way 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 low-cost Amazon’s Choice Dlyfull battery checker for $18.99, unless it’s on sale. Either unit clearly displays the status of CR2032 batteries, as well as a number of other popular battery sizes and types.
Using a multimeter to check the battery voltage
If you never plan to expand your electrical testing routine beyond checking whether batteries are good or bad, or if you prefer simple, no-nonsense testers, you probably don’t need a multimeter. However, aside from testing the power of a disposable battery, there are many useful uses for a multimeter around the home and garage.
To use a multimeter to check the voltage of the CR2032 battery, you will need a meter that measures DC voltage (direct current). While some high-end multimeters can cost hundreds of dollars, most DIYers are well supplied with meters that cost a fraction of that. However, be prepared to spend a little more money than it would cost to buy one of the battery testers we mentioned earlier.
Another good option is the MM325 digital multimeter from Klein Tools. It costs $34.97, or about $30 when you buy it on Amazon, and has a 4.7 star rating with over 2,000 reviews so far. The MM325 is capable of measuring AC and DC voltages up to 600V, 10 amps DC, and 2 megaohms of resistance. It also has functions for checking 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 the voltage of a 3V CR2032.
With the MM325 selector set to 20V DC, touch the red lead of the meter to the positive side of the battery and the black lead to the negative side. New CR2032 batteries have a nominal voltage of 3V, usually up to 3.3V. CR2032 batteries with voltages between 2.7V and 2.9V are still working, while readings below 2.7V indicate the end of their life.
