what is a button battery

A button battery is a small, round battery shaped like a button or coin, used in things like watches, hearing aids, remotes, calculators, and key fobs.

What it is

These batteries are compact power sources that come in different sizes and chemistries, including lithium, alkaline, and silver oxide. They are also called coin cell batteries in many contexts.

Common uses

Button batteries are commonly found in:

• Watches.
• Hearing aids.
• Remote controls.
• Thermometers.
• Calculators.
• Car key fobs.

Safety note

They can be very dangerous if swallowed or inserted into the nose or ear, especially for children, because they can cause serious internal burns quickly.

Why people care

In everyday use they are convenient because they are small and long-lasting, but safety and proper disposal matter because even “dead” batteries can still be harmful.

TL;DR: A button battery is a tiny round battery used in small electronics, but it can be dangerous if swallowed.