LR44 batteries go in with the flat positive side facing up, and they slide or snap into a spring-loaded compartment
An LR44 battery is a small coin-shaped cell about the size of a dime. The flat side is positive (+), the ridged side is negative (−). Most devices that use LR44s have a battery compartment with a metal spring on one end and a flat contact on the other. The spring pushes against the negative side, and the flat contact touches the positive side. You slide the battery in with the flat side facing the flat contact, or you press it down until it clicks into place, depending on the device design.
Key Takeaways
- The flat positive side of an LR44 battery faces up or toward the flat metal contact in the compartment.
- The ridged negative side faces down or toward the spring.
- Some compartments require you to slide the battery in horizontally; others require you to press it straight down until it clicks.
- If the device does not turn on after you install the battery, remove it, flip it, and try again—you may have inserted it backward.
- LR44 batteries are common in watches, calculators, laser pointers, and small electronic toys.
Locate the battery compartment on your device
The compartment is usually on the back, bottom, or side of the device. Look for a small rectangular or circular door, often held closed by a tiny screw or a plastic tab. Some devices have a sliding cover instead of a door. If you cannot find it, check the instruction manual or the manufacturer's website—the manual will show you exactly where it is and how to open it.
If the compartment is held by a screw, use a small flathead screwdriver (often a jeweler's screwdriver works best). Turn the screw counterclockwise to loosen it, but do not remove it completely—just loosen it enough to lift the cover. If it is held by a plastic tab, gently pry the tab upward with your fingernail or a plastic tool. Do not use a metal tool on plastic tabs, as you can crack them.
Identify which way the battery should face
Inside the compartment, you will see a metal spring on one side and a flat metal contact on the other. The spring is always on the negative (−) side. The flat contact is always on the positive (+) side. The battery's flat side must face the flat contact, and the ridged side must face the spring.
Some compartments are labeled with a + and − symbol printed on the plastic. If yours is labeled, follow those markings. If not, remember this rule: flat side toward the flat contact, ridged side toward the spring. This is true for every LR44 battery in every device.
Insert the battery into the compartment
There are two common insertion methods. In the first method, you slide the battery horizontally into the compartment. Place the battery with the flat side facing the flat contact, then slide it in until it sits flat and the spring pushes against the ridged side. You should feel slight resistance as the spring compresses.
In the second method, you press the battery straight down into the compartment. Hold the battery with the flat side facing up, position it over the compartment, and press down gently until you hear or feel a click. The battery should sit flush with the compartment opening. Do not force it—if it does not click or slide smoothly, remove it and check that you have the correct orientation.
Close the compartment and test the device
Replace the cover and tighten the screw (if there is one) by turning it clockwise. Do not over-tighten—just snug enough that the cover does not rattle. If the compartment has a plastic tab, push it down until it clicks or snaps into place.
Turn on the device or press a button to test it. If it works, you have installed the battery correctly. If it does not work, turn it off, open the compartment again, and remove the battery. Flip it so the ridged side now faces the flat contact, reinsert it, close the compartment, and test again. If it still does not work, the battery may be dead or the device may have a different problem—try a fresh LR44 battery from a new package.
What to do if the battery is stuck or difficult to remove
If you need to replace the battery later and it is stuck, do not pry at it with a metal tool, as you can damage the compartment or the battery itself. Instead, tilt the device so the compartment opening faces downward and gently tap the back of the device. The battery should fall out. If it does not, use a plastic spoon or a plastic tool to gently nudge the edge of the battery until it lifts slightly, then remove it by hand.
If the compartment itself is stuck or the screw is stripped, stop and do not force it further. Forcing a stuck screw can strip the hole permanently. If the device is under warranty, contact the manufacturer. If it is not, a watch repair shop or electronics repair service can open it safely.
Common devices that use LR44 batteries
LR44 batteries power watches, small digital thermometers, calculators, laser pointers, key-chain lights, hearing aid batteries (though some hearing aids use different sizes), electronic scales, and small electronic toys. Some devices use a single LR44; others use two or more in series. Check your device's manual to find out how many batteries it needs and whether they should all face the same direction or alternate.
If your device uses multiple batteries, they are usually stacked on top of each other in the same compartment. Install them one at a time, making sure each one sits flat before adding the next. The first battery's ridged side faces the spring, the second battery's flat side faces the first battery's flat side, and so on, until the last battery's flat side faces the flat contact.
Frequently Asked Questions
What happens if I put the battery in backward?
The device will not turn on or will not work. No damage occurs—the battery straightforward does not make contact with both terminals. Remove it, flip it, and try again. If the device still does not work after you flip it, the battery may be dead or the device may have another problem.
Can I use a different size battery if I do not have an LR44?
No. LR44 batteries are a specific size and voltage. Using a different size will not fit the compartment, and using a different voltage can damage the device. Always use the exact battery type listed in the manual or printed on the compartment cover.
How long does an LR44 battery last?
It depends on the device and how often you use it. In a watch worn daily, an LR44 typically lasts one to three years. In a device used occasionally, like a laser pointer, it can last much longer. Check the device manual for an estimate specific to your model.
Is it safe to leave a dead LR44 battery in the device?
A dead battery itself is safe to leave in, but a leaking battery can damage the compartment and the device's circuitry. If a battery has been in the device for a long time and the device has stopped working, remove the battery and inspect it for corrosion or leakage. If you see white or blue-green powder, clean the compartment with a dry cloth and replace the battery.
Do I need to remove the battery if I am not using the device for a long time?
If you will not use the device for several months, removing the battery is a good idea. It prevents the battery from leaking and draining inside the compartment. Store the battery in a cool, dry place and reinstall it when you are ready to use the device again.