How long do Subaru key batteries last?

The typical lifespan of a Subaru key fob battery is about 3 to 5 years under normal use. Real-world results vary based on how often you use the remote, the features you rely on, and the climate where you live.

Typical lifespan and what affects it

Key fob batteries wear out over time, and several factors influence how long they stay charged. Here is a breakdown of what to expect and what can shorten or extend their life.

• Standard battery type and life: Most Subaru fobs use a CR2032 3V lithium coin cell, with a typical life of about 3–5 years in normal use.


• Model year and feature set: Some models or trims with extended remote features may draw slightly more power, potentially reducing life a bit.


• Usage patterns: Frequent use of lock/unlock, remote start, or panic functions can drain the battery faster than sporadic use.


• Climate and temperature: Extreme heat or cold can shorten battery life and reduce performance temporarily.


• Direct exposure factors: Prolonged storage in hot environments or frequent dropping can affect the fob’s electronics leading to earlier replacement.

In practice, many Subaru owners replace the key fob battery every few years, with some seeing a longer life and others encountering shorter intervals due to heavy use or harsh conditions.

Battery type variations by model and year

Battery sizes are generally standardized, but there can be small differences by model or year. Knowing the exact type helps ensure you buy the right replacement kit.

• Common types used: The vast majority of Subaru key fobs use a CR2032 3V lithium coin cell. Some older or certain trims may use a CR2025 or a similar compact battery.


• How to confirm: Check your owner’s manual, inspect the back of the fob for the battery size label, or purchase a rechargeable or standard CR2032 kit and confirm compatibility before opening the fob.


• Replacement window by model: While 3–5 years is typical, some drivers report 2–3 years with heavy use, and others see 5+ years with light use and mild climates.

Understanding these variations helps you plan ahead and avoid being stranded when the battery fades.

How to replace a Subaru key fob battery

Preparing ahead saves time and ensures you don’t lose key functionality. Here are the typical steps used for most Subaru fobs.

1. Identify the correct battery type (most often CR2032) by checking the fob label or the owner's manual.


2. Use a small flat tool or coin to gently pry apart the two halves of the fob at the seam.


3. Remove the old battery, noting the orientation (positive side usually faces up).


4. Insert the new battery with the correct polarity, ensuring it sits flat and contacts the terminals.


5. Snap the fob halves back together and test by pressing a button to confirm a functional signal.

Note: In most cases, you do not need to re-pair the fob with the vehicle after a simple battery replacement. If the vehicle doesn’t recognize the key, consult the manual for resynchronization steps.

Signs your Subaru key battery is dying

Watch for indicators that the battery is nearing depletion so you can replace it before it fails completely.

• Reduced unlock/lock range or delayed response from the fob.


• Weak or no LED indicator on the fob when pressed.


• Frequent need to press buttons multiple times for a response.


• Remote start or panic alarm failing to activate reliably.

If you notice these signs, it’s a good idea to replace the battery soon to avoid being locked out or unable to start your vehicle remotely.

Bottom line

For most Subaru owners, a 3–5 year battery life is a reasonable expectation for standard key fobs. Variations arise from usage, climate, and the exact battery type used by your model year. Regular checks and a quick DIY replacement can keep your fob dependable without trips to the dealership.

Summary

Summary: Subaru key fob batteries typically last 3–5 years, with life affected by how often you use the remote, the features you activate, and environmental conditions. Most fobs use a CR2032 coin cell, though some models may use CR2025. Replacement is a straightforward DIY task: open the fob, swap in a fresh battery with the correct orientation, and reassemble. If the fob still underperforms after replacement, check for a need to re-sync with the vehicle or consult the owner's manual for model-specific guidance.

How do I know if my car key needs a new battery?

You can tell a car key fob battery is low by noticing a decreased range of operation, where you have to be closer to the car for the fob to work, and inconsistent button response, requiring multiple clicks to lock or unlock the doors. Other signs include a delayed response from the car, the LED light on the fob being dim or off, and your car displaying a warning message on the dashboard. 
This video demonstrates how to identify common signs of a low key fob battery: 44sTA Automotive technologyYouTube · May 9, 2025
Common signs of a low battery

• Reduced range: The key fob's working distance becomes significantly shorter than usual. 
• Inconsistent or delayed response: You may need to press buttons multiple times, or there could be a delay between pressing a button and the car responding. 
• Dim or non-illuminating LED: The small light on the fob may not light up at all, or it may be very dim when a button is pressed. 
• Dashboard warning: Your car's dashboard may display a message like "Key Battery Low" or "Replace Key Battery". 
• Push-to-start issues: If you have a push-to-start vehicle, the car may display a message to "push with key fob to start" even when the fob is inside the vehicle, especially when the battery is completely dead. 

What to do if you notice these signs

• Test a backup: If you have a second key fob, test it to see if the issues persist. If the second fob works normally, the first one definitely needs a new battery. 
• Replace the battery: Most key fobs use a common coin-cell battery, like a CR2032 or CR2025, which can often be replaced in a few minutes. 
• Use the physical key: If the battery dies completely, you can usually find a physical key hidden inside the fob. This can be used to manually unlock the door. Your car can still be started by placing the fob in a specific slot, even without battery power. 

How do I know if my Subaru key fob battery is dying?

You can tell a Subaru key fob battery is low by symptoms like a decreased operating range, which forces you to be closer to the car for it to work, or inconsistent button response. Other signs include the car displaying a dashboard warning light or message, or the key needing multiple presses to unlock. 
This video demonstrates the symptoms of a low key fob battery: 44sTA Automotive technologyYouTube · May 9, 2025
Key indicators of a low battery

• Reduced range: The distance at which the fob works shortens significantly. You may have to be much closer to the car for it to lock or unlock. 
• Inconsistent or delayed response: The buttons may not work every time you press them, or there might be a delay before the car responds. 
• Multiple presses: You find yourself pressing the unlock or lock button multiple times to get the fob to work. 
• Dashboard warning: Newer models may show a warning light or message on the dashboard indicating the key fob battery is low. 
• Push-to-start issues: If your car has a push-to-start system, the car may display a message like "push button with key fob to start" and require you to hold the fob against the start button to turn it on. 

This video explains what to do when the key fob battery is dead: 59sTyson The Subaru Specialist YouTube · Nov 29, 2019
What to do when you notice these signs

• Replace the battery: The solution is to replace the battery, which is typically a CR2032 coin cell for many Subaru fobs. 
• Use the manual key: Keep the physical, hidden key from inside your fob handy as a backup to unlock the door manually. 
• Replace the battery sooner rather than later: Even with a low battery warning, you may have months before it completely dies, but some users have reported it can die within days, so it's best to replace it as soon as you notice the symptoms. 

Can you start a Subaru with a dead key fob?

Yes, you can start a Subaru with a dead key fob by holding the fob directly against the push-to-start button. For a dead fob that won't unlock the door, you can use the physical emergency key inside the fob to get in. Once inside, and if the vehicle's battery is still charged, hold the fob against the start/stop button to engage the ignition. 
Steps to start a Subaru with a dead key fob
This video demonstrates how to get into your Subaru and start it when the key fob battery is dead: 44sAlex PrestigiacomoYouTube · Jun 1, 2021

1. Unlock the door: If the doors are locked, use the physical key blade to unlock the driver's door. This emergency key is hidden inside the fob and can be accessed by pressing the release and pulling it out. 
2. Enter the vehicle: Once you have the physical key in hand, unlock the door manually. Be aware that the car alarm may sound since the fob's signal to disarm it won't work. 
3. Start the car: With the physical key still in your possession, get into the driver's seat. Press the brake pedal and hold the key fob directly against the push-to-start button to start the engine. 
4. Replace the fob battery: After you've started the car, you should replace the battery in your key fob as soon as possible. 

How long should a Subaru key fob battery last?

The Subaru key fob battery life should be around three years, but climate conditions and usage frequency can cause the average life span of a key fob battery to vary.