A CR2016 will not work reliably as a replacement for a CR2032, even though they look similar

The two batteries are the same diameter (20 mm) but different thicknesses: a CR2016 is 1.6 mm thick, and a CR2032 is 3.2 mm thick. The extra thickness in a CR2032 means it holds roughly twice the charge. When you force a thinner CR2016 into a device designed for a CR2032, it may make electrical contact at first, but the connection is loose and unreliable. The device will either not turn on, turn on and off randomly, or work for a few minutes before dying.

The battery compartment in your device has a spring or contact point that expects the battery to sit at a specific depth. A CR2016 leaves a gap, so the spring cannot push the battery firmly against the contact. This is not a safe workaround—it can cause the device to malfunction at a critical moment, like a car key fob failing to unlock your car or a glucose meter giving a false reading.

Key Takeaways

  • A CR2016 is thinner than a CR2032 and will not sit flush in a compartment designed for the thicker battery.
  • The loose fit creates an unreliable electrical connection that causes devices to fail or work intermittently.
  • Using the wrong battery size can damage the device's contacts or cause it to malfunction when you need it most.
  • Always use the exact battery size your device manual specifies; the correct replacement is usually inexpensive and widely available.

Why the thickness matters more than you might think

Battery compartments are engineered with tight tolerances. The spring or metal contact inside is positioned to press against a battery of a specific height. When you insert a battery that is 1.6 mm shorter, that contact point no longer applies consistent pressure. Inconsistent pressure means inconsistent electrical contact, and inconsistent contact means the device cannot draw power reliably.

This is especially risky in devices where a power loss could be dangerous or inconvenient: car key fobs, medical alert buttons, hearing aids, or watches. A device that works intermittently is harder to troubleshoot than one that does not work at all, because you may not realize it has failed until you actually need it.

What happens if you try it anyway

In some cases, a CR2016 may appear to work in a CR2032 compartment because the spring is loose enough to make contact despite the gap. However, this contact is fragile. Vibration, temperature changes, or even the angle at which you inserted the battery can break the connection. You may test the device and find it works, then put it away, and discover weeks later that it has stopped working.

In other cases, the battery will not make contact at all, and the device will not turn on. This is actually the safer outcome because you know when ready that something is wrong. The dangerous scenario is the one where the device works sometimes, because you may trust it when it is not reliable.

The right battery is cheaper than the problem it prevents

A CR2032 costs between 50 cents and two dollars at any pharmacy, supermarket, or hardware store. A CR2016 costs about the same. The cost difference is negligible. The cost of replacing a device that failed because of a bad battery connection, or the inconvenience of a key fob that does not work when you need it, is much higher.

If you cannot find a CR2032 locally, you can order them online and receive them within a few days. Most people keep a spare or two on hand because these batteries are so common. If your device is urgent and you do not have the right battery, it is better to buy a CR2032 than to gamble on a CR2016.

How to find the correct battery for your device

Check the device manual first—it will list the exact battery model. If you do not have the manual, look inside the battery compartment itself. Many devices print the battery size on the compartment door or on a label inside. If the compartment is empty and unmarked, search the device model number plus "battery" online, and the manufacturer's specifications will tell you what size it uses.

Once you know the size, buy that size. Do not assume that a battery that fits is the right one. The CR2032 is by far the most common coin cell battery in consumer devices, so if you are unsure, that is a reasonable guess—but verify before you buy.

Other coin cell batteries and why they are not interchangeable either

The coin cell family includes CR2025 (2.5 mm thick), CR2016 (1.6 mm), CR2032 (3.2 mm), and others. They all have the same diameter but different thicknesses and different capacities. A CR2025 will not reliably replace a CR2032 for the same reason a CR2016 will not. A CR2032 will not fit in a compartment designed for a CR2016 because it is too thick.

The battery size is not arbitrary—it is chosen to fit the device and provide the right amount of power for the expected lifespan. Using a different size compromises both the fit and the power supply. Stick to the size your device specifies.

Frequently Asked Questions

Will a CR2016 damage my device if I use it?

It is unlikely to cause permanent damage, but it may cause the device to malfunction or fail to work at all. The loose fit creates an unreliable connection, which can cause the device to behave unpredictably. Remove it and use the correct battery size.

What if my device works fine with a CR2016?

It may work now, but the connection is not stable. Vibration, temperature, or time can break the contact. Replace it with a CR2032 as soon as you can to avoid the device failing when you need it.

Can I stack two CR2016 batteries to make up the thickness?

No. Two batteries stacked together will not fit in a single-battery compartment, and even if they did, the electrical connection would not work the way the device expects. Use one CR2032.

Where is the easiest place to buy a CR2032?

Pharmacies, supermarkets, and hardware stores all stock CR2032 batteries in their watch or battery sections. They are also widely available online. Most cost less than two dollars.

Is there any device where a CR2016 can safely replace a CR2032?

Not reliably. Even if a device happens to work with a CR2016, the connection is loose by design, and the battery will not last as long. Use the battery size the device specifies.