The Subaru key fob battery is a small yet important component for the convenience, safety, and security of your car. The basic functions of remote door locking, alarm activation, and the push-button starter are entirely dependent on this small lithium battery in the key fob. When the battery is weak, the driver will need a greater range, slower responsiveness, and warning signs, and the entire system might stop working. In most cases, owners think the key fob is the cause of the problem, yet it is usually a low or flat battery.
This is the complete guide that will tell everything that Subaru users can know about key fob battery such as how it works, what kinds of batteries can be used and which type of battery is appropriate with specific models, how long can it last, what are the warning indicators, how to replace it correctly, how much it would cost with other brands, how to troubleshoot, how to start in an emergency, safety tips and maintenance plans.
Table of Contents
What Is a Subaru Key Fob Battery and How Does It Work?
A Subaru key fob battery is a small lithium coin cell that powers the key fob’s electronic components. They are a microprocessor, a radio-frequency transmitter, and a proximity sensor (on models equipped with keyless entry and a push-button starter).
When a button on the key fob is pressed, the battery sends an encrypted RF signal to the vehicle. The car receiver matches this signal against stored authentication codes. When the signal matches, the car will perform the requested action: unlock the door or switch off the alarm.
Proximity detection is also enabled in push-button-start models that use the battery. The car can start with the key fob, even though the key is not in it, because the engine activates as long as the key fob is in range.
Why the Subaru Key Fob Battery Is So Important
The most sophisticated Subaru key systems will not function well without sufficient battery power.
Less than ideal voltage to the battery may result in:
- The locking and unlocking are intermittent.
- Delayed signal response
- Failure of the keyless entry
- The push-button start is not recognizing the key.
- Failure to deactivate the alarm system.
Even though Subaru key fobs include a passive transponder chip for emergencies, the battery is critical for daily driving convenience.
Subaru Key Fob Battery Size Explained
It is essential to know the size of the Subaru key fob battery to ensure it performs well and lasts long. Subaru relies heavily on lithium coin cell batteries due to their small size, constant-voltage output, and long shelf life.
CR2032 Battery (Most Common)
The most common is the CR2032 battery that is used in the current Subaru.
Specifications
- Voltage: 3 volts
- Diameter: 20 mm
- Thickness: 3.2 mm
- Higher energy capacity
- Longer lifespan
This battery is effective in promoting high-caliber proximity sensors and push-button ignition systems.
CR2025 Battery (Older or Basic Models)
Earlier Subaru key fobs contained the CR2025 battery.
Specifications
- Voltage: 3 volts
- Diameter: 20 mm
- Thickness: 2.5 mm
- Lower capacity than CR2032
An improperly sized battery can result in loose contact or rapid battery depletion; therefore, it is always essential to ensure the correct battery is used.
Subaru Model-Wise Key Fob Battery Compatibility
Subaru models have different key fob designs; however, the battery requirements are usually similar.
Subaru Outback Key Fob Battery Replacement
- Subaru Outback (2015–Present): CR2032
Subaru Forester Key Fob Battery Replacement
- Subaru Forester (2014–Present): CR2032
- Subaru Forester: key fob battery type: CR 2032.
Other Subaru Models
- Crosstrek: CR2032
- Impreza (2008–2014): CR2025
- Impreza (2015–Present): CR2032
- Legacy: CR2032
- WRX / STI: CR2032
- Ascent: CR2032
- BRZ: CR2032
Always check the owner’s manual or the key fob casing.
How Long Does a Subaru Key Fob Battery Last?
The average life expectancy of a Subaru key fob battery is 2 to 4 years. But the real-life span varies according to a number of factors.
Factors Affecting Battery Life
Frequency of Use
The battery drains quickly from frequent lock/unlock cycles or remote start.
Proximity to Vehicle
The proximity to the car (in a garage) means the key fob is constantly in communication, so battery life will be reduced.
Temperature Extremes
Freezing winters and hot summers shorten the lifespan of lithium batteries.
Battery Brand Quality
The premium brands have considerably longer durability than the generic batteries.
Radio Frequency Interference
Highly RF environments in the city can enhance signal transmission, which can discharge the battery.
Warning Signs of a Weak Subaru Key Fob Battery
A battery experiencing problems will usually give indications of imminent failure.
Common symptoms include:
- Reduced operating range
- However, there is a slow lock / unlock.
- There are numerous button presses necessary.
- – “Key Battery Low” car warning.
- Push-button start cannot always detect the key.
- Keyless failure to start and stop.
Early battery replacement prevents inconvenience and lockouts.
Subaru Key Fob Battery Replacement: Step-by-Step Guide
Learning how to replace a Subaru key fob battery is simple and does not require special tools or programming.
Tools Required
- Flat-head screwdriver /coin.
- New lithium battery (CR2032 or CR2025)
- Clean, dry surface
Subaru Key Fob Battery Changing Process
- Take out the backdoor physical key.
- A small notch or slot is to be located on the casing.
- Insert a coin or a screwdriver into the slot.
- Twist softly to divide the fob in half.
- Change the old battery handle with great care.
- Put in the new battery, and face the positive side upwards.
- Make specific contact with terminals.
- Make sure the halves of the fob fit together.
- Continue pressing until the casing clips.
- Test all buttons
This method fully explains how to change battery in Subaru key fob safely and efficiently.
Subaru Key Fob Battery Spring: What You Should Know
In a key fob, a metal battery spring has a variety of small contacts, or a Subaru key fob battery spring, that press against the battery terminals. These springs ensure stable electrical contact.
In case the spring is bent or soiled:
- The key fob may not power on
- Intermittent transmission of signals may occur.
- Replacement of the batteries can be unsuccessful.
Look closely, and when changing the battery, remove the spring carefully and re-bend it, if necessary.
Subaru Key Fob Battery Replacement Cost
When you replace the battery in the Subaru key fob at home, the cost is low.
| Replacement Method | Estimated Cost |
| DIY Replacement | $2–$10 |
| Dealership Service | $20–$50 |
Replacement can be performed by a person without spending a lot of time and money, and without visiting the dealership, unless there are special reasons.
Subaru Key Fob Not Working After Battery Replacement
If there is no response from your key fob after installing the battery, the problem is not serious.
Common Causes
- The battery is fitted face downwards.
- Battery not seated properly
- Bent or dirty contacts
- Weak or defective battery
- Casing that is not completely clamped.
Solutions
- Install the battery back in its proper place.
- Wipe contacts using a dry cloth.
- Try a new branded battery
- Make sure that the fob casing is closed.
Do You Need Reprogramming After Battery Replacement?
No. Subaru key fobs do not lose their programming when the battery is removed. After a fresh battery is installed, the fob returns to regular operation.
Emergency Starting With a Dead Subaru Key Fob Battery
Subaru cars come with backup mechanisms even when the battery is dead.
Push-Button Start Emergency Method
- Touch the key fob on the start button.
- Press the brake pedal
- Push the start button
The vehicle reads the transponder chip even when the battery is not functioning.
Using the Hidden Physical Key
- Take the fob key and delete it.
- The driver’s door is unlocked by hand.
- Follow the emergency start procedure given in the owner’s manual.
Best Battery Brands for Subaru Key Fobs
When the battery quality is high, the lifespan is long, and the performance is reliable.
Recommended brands:
- Panasonic
- Energizer
- Duracell
- Sony
- Maxell
Do not use non-brand or poor-quality batteries.
Subaru Key Fob Battery Safety Tips
- Keep batteries away from children.
- Use old batteries properly.
- Never confuse old batteries with new batteries.
- Do not touch the battery terminals with your bare hands.
- Keep store batteries in dry, cool locations.
Subaru Key Fob Battery Maintenance Tips
- Change the battery every 2-3 years.
- Do not keep the key fob in the moisture.
- Do not drop or squash the fob.
- When on the road, keep a spare battery.
- Monitor dashboard warning.
Conclusion
The small but essential element related to the car is the Subaru key fob battery, which powers many of the car’s key features. Knowing the battery size, compatibility, warnings, replacement tips, cost, emergency options, and changing practices enables Subaru owners to eliminate avoidable stress and unnecessary dealing costs. Your Subaru key fob can provide reliable service for you in the coming years with timely replacement and proper care.
FAQs
Q1. What kind of battery is in a Subaru key fob?
Ans: Most Subaru key fobs use a CR2032 lithium coin cell battery, while some older models use a CR2025.
Q2. How to replace the battery in the Subaru key?
Ans: Open the fob with a coin or screwdriver, remove the old battery, insert a new one with the positive side up, and snap the fob closed.
Q3. What kind of battery does a 2017 Subaru Forester key fob take?
Ans: The 2017 Subaru Forester key fob uses a CR2032 battery.
Q4. Do I have to reprogram my key fob after replacing the battery?
Ans: No, Subaru key fobs do not require reprogramming after a battery change.
Q5. Why is my Subaru key fob not working after a battery change?
Ans: It usually happens if the battery isn't properly seated, the contacts are dirty, or the battery is defective.