Learn which plants thrive in your Hardiness Zone with our new interactive map!

How to Find the Right Size Clock Battery

By Suzie Faloon
Many clocks run on batteries or battery back-up systems.
Jupiterimages/Photos.com/Getty Images

Battery operated clocks are convenient for power outages, overnight travel and for areas of the home that have insufficient electrical outlets. When you throw away the manufacturer's paperwork and box the clock comes in you may lose information that identifies the required battery size. If you buy a clock at a thrift store, flea market or yard sale the information will rarely be provided. You will be able to identify the battery size when you check the battery compartment and labels on the unit.

Look for the battery panel on the back, bottom or side of the clock unit.

Open the compartment panel by pulling the tab or by sliding it backward. The compartment may be opened by inserting a small flathead screwdriver into the indent in the panel to pop it up. A Phillips screwdriver will be required to open a panel that has tiny screws holding it securely closed.

Check the backside of the panel opening to see if there is a sticker with the battery requirements printed on it. If the panel is plastic the battery type may be imprinted in the material.

Look for the area in the compartment where the battery is to be placed if the information is not on the cover. The battery size should be etched or embedded in the bottom of the compartment. For instance, the symbols 9V or AA may be visible in the bottom of the area where the batteries will be placed.

Check for a second compartment on a clock that has a musical or pendulum feature. For an example, an anniversary clock has separate battery needs for its functions.

Place various batteries into the compartment on the clock if there are no visible identifying markings with the size listed on it. The flat end of the battery is set against the coil in the compartment. Check to see which battery fits snugly into the unit.

Hold a measuring tape against the well indentation to measure the width of a round battery for small timer clocks. Write down the measurement to compare sizes at the store.


Things You Will Need

  • Flat head or Phillips screwdriver
  • Measuring tape


  • Take your clock to a jeweler or a person who repairs clocks if you can not determine the size of the battery needed to operate the clock.

About the Author


Suzie Faloon is a freelance writer who has written online content for various websites. As a professional crafter and floral designer, Faloon owned a florist business for nearly 25 years. She completed the Institute of Children's Literature course in 1988.