Garage Door Opener Battery Size

Automatic garage door openers require electrical power to operate. But since power outages can hit at the most inconvenient time, garage door openers with a battery backup have become increasingly popular.

A backup battery allows for uninterrupted garage door operation even when there is no electricity. 

If your garage door opener brand is LiftMaster, Genie, Mastercraft, Chamberlain, or Linear, the unit is likely to have a battery backup or the option to add one. 

But what garage door opener battery size is right for you? If you are to add a backup battery to your opener, you will need an answer to this question. Read along for some help. 

Also Read:

What garage door opener battery size do you need?

The correct physical size of your garage door opener battery depends on the model or type of opener in your garage. In any case, most garage door opener batteries with a compartment in the motor unit are about 9cm by 20cm by 7cm. Batteries installed over the motor unit’s housing tend to be larger, approximately 21cm by 31cm by 14cm. 

Various brands may have different motor unit designs determining the physical size of the battery compartment and the battery itself. Additionally, the power rating of an opener may determine the battery size for a specific garage door opener. 

An opener with a larger motor unit can accommodate a bigger battery compartment, allowing for a slightly bigger battery size. 

The physical size notwithstanding, manufacturers offer a 12-volt battery inserted into the opener motor unit or installed over the unit’s housing. The backup battery sizes may vary slightly from brand to brand, but the voltage rating is generally the same. 

What is the best battery for a garage door opener?

Lithium-ion batteries are the most common and best battery types for garage door openers. They pack more power than other battery types and boast greater energy densities, making them long-lasting. 

These batteries pack enough power to complete up to 20 full garage door open-close cycles when fully charged.

What to look for when buying a garage door opener battery

Many garage door opener models now come with a backup battery for use during power failures. 

However, if your opener does not originally come with a built-in battery but supports one, you can buy a compatible battery and install it over the motor unit casing. 

Not all backup batteries are created equal, so you will need to know what to look for when buying one for your opener. 

This section provides a detailed look at the factors to consider when buying a garage door opener battery. 

  • Battery size  

Most brands have standardized sizes for their batteries. However, some manufacturers make their battery sizes proportional to the battery’s capacity. 

So, while this is likely to be a minor consideration, it may be significant if you buy from a manufacturer whose battery sizes determine their capacity.

You want a battery with a higher capacity to supply the needed energy for longer on a single charge. 

If your motor unit already has a battery compartment, you can open it and check the dimensions to determine the battery size you need. 

Otherwise, consult the manufacturer for the dimensions recommended for your garage door opener model. 

  • Brand 

Backup batteries are mostly brand specific. This means the battery used on your motor unit must be from the same manufacturer as the garage door opener. 

Your unit may be compatible with specific battery models, so we recommend checking with the manufacturer for compatibility before settling on a purchase. 

  • Battery voltage  

Most garage door openers work with a 12-volt battery. However, your model could include a provision for alternative voltage ratings, including 3-volt and 9-volt batteries. 

It is crucial to check the voltage rating of your opener to ensure you are getting the correct voltage on the battery to avoid incompatibilities. 

For standard garage door openers, a 12-volt lithium-ion battery should be the ideal choice, providing longer usage before recharge.

  • Manufacturer reputation 

We have mentioned that backup batteries are mostly manufacturer-specific. Still, in cases of compatible batteries from a different manufacturer, ensure you consider the reputation of the battery maker.

Buying from the most reputable manufacturer will likely give you the best bang for your buck. 

Experienced manufacturers tend to produce high-quality products likely to work as desired. A battery from such a manufacturer will likely be reliable and durable.

  • Durability rating of the battery 

A battery with a longer lifespan is cost-effective and will save you money in the long run as you will have it for longer. 

On the other hand, a shorter lifespan means the battery will serve you for a limited period before breaking down and requiring replacement. 

Purchasing replacements frequently can amount to accumulated long-term costs, driving up the battery price even if it is inexpensive upfront. 

How to change the battery in your LiftMaster garage door opener

Backup batteries for garage door openers have a service life of about one to two years. If you buy one, prepare to replace it every two years. 

If you own a LiftMaster garage door opener, you can tell when it is time to replace the battery when the battery status LED on the motor unit turns red. The opener will typically beep once before the battery status LED lights up and stays on. 

When you see these indicators, it is time to replace the battery on your LiftMaster garage door opener unit. 

Your first task is to get a replacement battery designed to work with the LiftMaster unit. After that, follow the procedure below to remove the used battery and install the replacement. 

Tools and materials you will need 

  • A pair of gloves 
  • Eye protection 
  • Stepladder for reaching the motor unit of your garage door opener
  • Screwdriver for opening and closing the battery compartment

Procedure for replacing the battery in your LiftMaster opener 

Once you have assembled the supplies you need to complete this task, wear gloves and safety goggles for your eye protection. This protection is recommended when opening the battery compartment. 

After that, set the stepladder under the motor unit and follow these steps to replace your old backup battery. 

This procedure should work for any LiftMaster garage door opener, regardless of the model. 

Step 1: Unplug the opener from the outlet

You should always disconnect an electrically powered device from the outlet before performing any repairs or activities that involve opening their parts. 

Disconnecting the garage door opener from the electrical outlet will help prevent any risk of electrical shock during the replacement.

So, climb a stepladder and pull the power cord from the outlet before accessing the battery compartment. 

You need a stepladder to reach the outlet because overhead units are typically installed high in the ceiling. 

Step 2: Open the light lens to access the battery compartment 

Your LiftMaster backup battery compartment is usually inside the light cover, next to the light bulb. Therefore, you will need to pop the cover open to access the battery compartment. 

With the electrical plug disconnected from the outlet, it should be safe to open the battery compartment and pull the old one out.

Depending on your design, you may use a screwdriver to loosen a screw or two holding the battery door in place. 

Once this is done, the battery compartment cover will come off, allowing you to access the old backup battery. 

Pull out the battery from the slot and gently disconnect the black and red wires from the terminals.

Step 3: Install the replacement backup battery 

The next part is to reverse the entire procedure you followed when removing the used battery. If you need help with the correct positioning of the new battery, consult your user’s manual for the specifics.

Start by connecting the black and red cables to their respective terminals on the new battery. The battery should have markings and color codes indicating which side is live and which side is neutral.

This means the red cable should attach to the red terminal and the black wire to the black terminal on the battery.

Next, carefully insert the battery into the slot, checking to ensure the wires are not pinched. 

Afterward, place the battery compartment door back and secure it with the screw.

Finally, replace the light cover over the bulb to finish the installation. 

Step 4: Charge your new battery 

Manufacturers recommend charging a new backup battery for 24 hours before using it to power the LiftMaster garage door opener.

Start by plugging the power cord back into the electrical outlet to power up the garage door motor unit. 

Once that is done, you should see the battery status LED blink. The charging indicator light on your LiftMaster opener is green. This should show that your new backup battery is charging.

The blinking green LED will turn solid green when the new battery has received a full charge.

Step 5: Test your new battery

The green battery status LED should be a good indicator of a charged, healthy battery. However, you don’t want to wait till a power outage hits to find that your battery is defective. 

The chances of your battery being faulty are minimal, but you should still test it to be sure. It helps to err on the side of caution. 

So, switch to the battery mode by cutting the motor unit’s power supply and allow the new backup battery to prove itself. 

  • Use the stepladder to reach the electrical cord on the opener. Pull it from the outlet to disconnect the unit from the power mains. 
  • Observe the battery status LED for a color change. The light should turn to a solid orange, indicating that the garage door opener has switched to battery mode.
  • Use the remote, the keypad on the inside garage wall, or the keyless pad on the side of the garage door to activate the garage door. 
  • If the garage door opens and closes as usual, the backup battery has a full charge and is working properly. If the door runs slower than usual, the battery is low. To confirm this, check the battery status LED on the motor unit—it should be flashing orange. 

If you are happy with the test results, climb the stepladder and plug the unit back into the power mains. 

The video shows how to change battery in Chamberlain garage door opener

How long does LiftMaster battery last?

The backup battery for a LiftMaster garage door opener has a one- to two-year lifespan under normal use. The opener will typically beep, and the battery status LED will turn red to indicate the end of the battery’s service life. 

Since the garage door opener can beep due to other reasons as well, checking the battery status LED for a solid red color should help you confirm when to replace the battery. 

Frequently Asked Questions 

How long does a garage door backup battery last?

The backup battery for a garage door opener lasts about one to two years with normal usage. Your battery typically recharges automatically during regular use and powers the motor when the power goes out. 

What size battery goes in a garage door remote?

The remote control for most garage door openers uses a 3‑volt lithium battery. For LiftMaster remote controls and accessories, the option is typically a CR2016 or CR2032 battery with a 3-volt rating. 

What battery does a Genie remote use? 

The Genie company’s IntelliCode remotes use 12-volt alkaline batteries compatible with multiple Genie remote models, including the GIFTD-1, GMIC-2, GIT-1, and GIT-3.  

What is a CR2 battery?

A CR2 battery is a non-rechargeable lithium-ion cell with a cylindrical profile measuring 27mm by 15.6mm. The battery is designed for use in shutter remotes, older film cameras, compact flashlights, and multiple other small devices. 

Conclusion on garage door opener battery size 

The battery sizes for garage door openers may vary depending on the manufacturer and the motor unit on your opener. However, most units use a small 12-volt backup battery that can fit inside the opener’s battery slot on be installed over the casing. 

If you want uninterrupted garage door operation, consider getting a garage door opener with a battery backup or buy a compatible battery for your existing unit. 

Let us know what you think in the comments.