garage doors sensors have batteries

In this high-tech day and age, having an automatic garage door opener is something we take for granted. You push a button as you’re nearing your driveway. Then, as if by magic, the garage door starts to open in anticipation of your arrival.

While it seems simple enough, there are multiple working parts that help get this done. There’s the motorized device that pulls the door up and down the tracks. Then, there’s the remote, the keypad, and most importantly, the sensors.

Many homeowners forget that their garage door system operates wirelessly. One common question we hear a lot is: do garage door sensors have batteries?

This post will discuss how garage door sensors work and what to do if yours starts to malfunction.

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Do Garage Door Sensors Have Batteries

Yes, they do. Garage door sensors work wirelessly and use a 3-volt disc-shaped battery. It’s called a coin cell battery, and you can find it at retailers, grocery stores, and online.

Each garage door sensor has a battery model that complies with its design and model. When replacing old batteries, make sure you take note of the number written on the back of the battery. It usually begins with a ‘CR’ followed by four digits, depending on the model. The CR stands for Chromium, which is used in making these batteries.

How Do Garage Sensors Work

Ever since 1993, residential automated garage doors have required safety sensors in compliance with US Federal Law UL 325. These essential safety features work to prevent closing on a person or an object in the way.

If they sense something is blocking the garage door, they’ll stop the garage door from closing. Then, the door will start to open up once again.

Traditional sensors used to rely on physical contact with an object to get the garage door to move in reverse. They’re known as ‘mechanical sensors.’

Nowadays, photoelectric sensors are more widespread. These rely on two garage door sensors that are attached on either side of the garage door.

You can place them anywhere from two to six inches off the ground. This is the perfect height for detecting small children, pets, bikes, and anything else blocking the garage door.

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An Overview of Photoelectric Garage Sensors

Photoelectric garage sensors are made up of two basic parts. For these two parts to work well, they should be perfectly aligned and facing each other.


The photo-eye system is what we call the infrared detector on each garage door sensor. It receives signals from the remote control when closing the garage door.

The main purpose of photo-eye is to scan the garage door entryway using infrared light waves. It helps make sure nothing or no one is in the way of the garage door as it’s closing to prevent injuries or accidents.

Line of Sight

Each sensor’s photo-eye system communicates with the other. They send infrared light beams back and forth when signaled with the remote control. We refer to this beam as the sensors’ line of sight.

Both sensors have indicator lights. It’s their way of ‘seeing each other.’ One sensor has a green light, which tells you that both sensors are in operation mode. This is what we call the transmitter, or sending eye.

The second receiving sensor has a red light that turns on when it’s aligned with the sending sensor. It verifies there are no obstructions between them, and it’s safe for the garage door to close.

If anything is in the way and blocks or interrupts this line of sight, the garage door will stop closing. Then, it’ll reverse direction and open once again.

When Is It Time to Replace the Batteries

Faulty garage door sensors can be a result of several reasons. The most common is that they need new batteries.

There’s a test you can carry out to check whether the garage door sensor batteries are working as they should. This test should be carried out every six months to make sure the sensors are in optimal condition.

Follow these steps:

  1. Close the garage door and keep it closed during the entire test.
  2. Press down on the battery test button on the garage door sensor.
  3. When you release the button, the LED indicator light on the sensor will give a brief flash.
  4. If you have a Smart Garage hub, it should beep once.
  5. Repeat this test six times.
  6. If the LED doesn’t flash or the hub doesn’t beep even once, it’s time to get new batteries.

Can I Replace the Batteries Myself

After carrying out the battery test, you may find your garage door sensors needing new batteries. So, it’s time to go out and get yourself new coin cell batteries.

Installing new batteries is quick and fool-proof. Follow these easy steps, and you’ll have yourself a fully functioning garage door sensor in no time.

  1. Some sensors have a release tab on the bottom to remove the cover. Others have a narrow slit on the bottom for a small screwdriver to pry open the cover. According to the type you have, remove the cover and proceed.
  2. After removing the cover, carefully slide out the battery from its slot.
  3. Make sure you dispose of the old battery properly.
  4. Put in a new coin cell battery. Make sure it’s the same model as the old one.
  5. Pay attention to the polarity orientation (the + and – ends) as you put in the new battery.
  6. Slide the cover back and press down until you hear it click into place.
  7. Press the battery test button, as we mentioned above, to confirm the battery is working.
  8. The LED indicator lights should flash, and the hub should give a beep.


So, do garage door sensors have batteries? They sure do!

Installing these sensors has been mandatory by law since 1993. So, it’s always a good idea to check on the state of their batteries every six months or so.

Maintaining your automated garage door’s safety features will protect the entire system. More importantly, it’ll keep you and your family safe every time you have to open or close the garage door.

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