Owner guide · Genesis of Elgin · Bartlett, IL
Genesis Key Fob Battery Replacement, Step by Step
A weak smart key battery can stop a Genesis key fob from working, and the fix takes a coin cell battery and a flat head screwdriver. This guide follows the 2027 GV80 (JX1) and 2027 G80 (RG3) owner's manuals on owners.genesis.com, read October 28, 2026: the battery type, the replacement steps, the warning message to watch for, and how to unlock and start the vehicle if the battery dies. Other Genesis models and years can differ, so check the manual for your vehicle.
What battery does a Genesis key fob use, and how do you replace it?
The 2027 GV80 and 2027 G80 owner's manuals list a CR2450 battery. To replace it: press button A to remove the keyring fixed appliance, insert a flat head screwdriver into the inner groove to remove the smart key cover, remove the old battery, then install the new battery and reinstall the cover in the reverse order. Make sure the battery position is correct.
Genesis smart key battery type
| Owner's manual | Smart key battery type |
|---|---|
| 2027 Genesis GV80 (JX1) | CR2450 |
| 2027 Genesis G80 (RG3) | CR2450 |
From the Replacing the battery section of each manual (GV80 printed pages 175-176; G80 page 5-11), read October 28, 2026 on owners.genesis.com.
If your Genesis is a different model or year, check the battery type in its owner's manual before you buy a replacement.
How to replace the smart key battery
Both manuals give the same steps:
- Press button A to remove the keyring fixed appliance.
- Insert a flat head screwdriver into the inner groove to remove the smart key cover.
- Remove the old battery.
- Install a new battery and reinstall the smart key cover in the reverse order of removal.
Make sure the battery position is correct. The manuals say an improperly positioned battery may discharge the battery and cause smart key failure. If you suspect the smart key has been damaged, or it still does not work correctly, they say to contact an authorized retailer of Genesis-branded products.
Both manuals warn that the smart key contains a lithium button battery, which can cause severe or fatal injuries within 2 hours if swallowed. Keep batteries out of reach of children, and seek immediate medical attention if you think one may have been swallowed or placed inside any part of the body. Dispose of used batteries according to local laws or regulations.
Signs your Genesis key fob battery is low
Both manuals describe a Low key battery message: when the Engine Start/Stop button is pressed to the OFF position, a message may appear on the cluster display indicating the smart key's internal battery is low. When you see it, replace the smart key battery.
The manuals also say to replace the battery if the smart key is not working properly. Before you do, note that they list other things that can stop a smart key from working, such as a nearby radio transmitter, a mobile phone or two-way radio, another vehicle's smart key being used nearby, metallic window tint, or a discharged vehicle battery. They suggest not keeping the smart key and your phone in the same pocket.
If the key fob battery dies
Unlock the door
Press the GENESIS text section of the mechanical key to remove the case, remove the mechanical key, and use it to lock or unlock the driver's door. Reinstall it in the reverse order after use.
Start the vehicle
If the smart key battery is weak or the key does not work correctly, start the vehicle by pressing the Engine Start/Stop button with the smart key, held as shown in the manual.
Lost a key?
A maximum of two smart keys can be registered to one vehicle. If one is lost, take the vehicle and remaining keys to an authorized retailer of Genesis-branded products, or tow the vehicle if necessary.
From the Smart key, Using mechanical key, Loss of a smart key and starting sections of the 2027 GV80 and 2027 G80 owner's manuals, read October 28, 2026.
Taking care of your smart key
The 2027 GV80 manual says to keep the smart key in a cool, dry place, because moisture or high temperature may cause its internal circuit to malfunction, which may not be covered under warranty. It also says to avoid dropping or throwing the smart key and to protect it from extreme temperatures.
Both manuals say to always take the smart key with you when you leave the vehicle; if it is left near the vehicle, the vehicle battery may be discharged.
Our service team at Genesis of Elgin can help with smart keys and the rest of your Genesis; you can schedule service online.
Genesis of Elgin service hours
| Days | Hours |
|---|---|
| Monday to Friday | 8 a.m.-5 p.m. |
| Saturday | 8 a.m.-3 p.m. |
| Sunday | Closed |
From Genesis of Elgin's website, October 28, 2026. The website lists Monday to Saturday service hours and none for Sunday. Holiday hours can differ.
Genesis key fob battery questions
What battery does a Genesis key fob take?
The 2027 GV80 and 2027 G80 owner's manuals both list the smart key battery type as CR2450. Other Genesis models and years can differ, so check the manual for your vehicle.
How do I know my Genesis smart key battery is low?
Both manuals say a Low key battery message may appear on the cluster display when the Engine Start/Stop button is pressed to the OFF position, indicating the smart key's internal battery is low. They also say to replace the battery if the smart key is not working properly.
Can I start my Genesis if the key fob battery is dead?
Yes. Both manuals say that if the smart key battery is weak or the smart key does not work correctly, you can start the vehicle by pressing the Engine Start/Stop button with the smart key, held as shown in the manual.
How do I get in if the smart key does not work?
Use the mechanical key hidden in the smart key. Press the GENESIS text section of the mechanical key to remove the case, remove the mechanical key, and use it to lock or unlock the driver's door.
What tool do I need to change a Genesis key fob battery?
The manuals' steps use a flat head screwdriver inserted into the inner groove to remove the smart key cover, after pressing button A to remove the keyring fixed appliance.
How many smart keys can a Genesis have?
Both manuals say a maximum of two smart keys can be registered to a single vehicle. If you lose one, they say to take the vehicle and remaining keys to an authorized retailer of Genesis-branded products, or tow the vehicle if necessary.
Smart key still not working?
Visit Genesis of Elgin at 1201 W. Lake St. in Bartlett, IL. Our service team can check your smart key and your vehicle.
Sources
The battery type, replacement steps, warnings, low battery message, backup start and mechanical key steps are from the 2027 GV80 (JX1) and 2027 G80 (RG3) owner's manuals on owners.genesis.com, read October 28, 2026. Other Genesis models and years can differ, so the manual for your vehicle is the final word. Address and hours are from Genesis of Elgin's own website. Image: Genesis Motor America.
- 2027 GV80 Owner's Manual (JX1): Replacing the battery; Using mechanical key; Loss of a smart key; Smart key precautions; Low key battery message; Emergency Starting, Genesis Motor America, read October 28, 2026
- 2027 G80 Owner's Manual (RG3): Replacing the battery; Using mechanical key; Loss of a smart key; Smart key precautions; Low key battery message; starting with a weak smart key battery, Genesis Motor America, read October 28, 2026
- 2027 GV80 (image), Genesis Motor America, October 28, 2026
- Address and service hours (structured data), Genesis of Elgin, October 28, 2026
- Genesis service center at Genesis of Elgin, Genesis of Elgin, October 28, 2026
