How to Change My Subaru Key Fob Battery

If your Subaru key fob suddenly needs a few extra presses… or you’re getting a “key fob battery low” warning on the dash… your battery is almost definitely on its way out.

The good news? You don’t need a dealer, a scan tool, or any special skills.

In this guide, you’ll see exactly how to change your Subaru key fob battery yourself—step by step—whether you drive an Outback, Forester, Crosstrek, Ascent, Impreza, Legacy, or WRX. You’ll learn:

How to quickly identify your Subaru key fob type
Which battery you actually need (CR2032, CR2025, or CR1620)
The safest way to open your Subaru key fob without breaking it
What to do if your Subaru key fob is not working after a battery change

No fluff. No guesswork. Just a simple, DIY Subaru key fob battery replacement that takes a few minutes, saves you money, and gets your remote working like new again.

Identify Your Subaru Key Fob Type

Before you replace a Subaru key fob battery, you need to know which key fob you have. Subaru uses a few different styles, and each one usually takes a specific battery type like CR2032, CR1620, or CR2025.

How to tell which Subaru key fob you have

Look at your key fob and match it to these quick descriptions:

Smart key / push-button start fob
- No metal key sticking out
- Has LOCK, UNLOCK, maybe TRUNK and PANIC
- Used with push-button start (“Keyless Access”)
- Most newer Outback, Forester, Crosstrek, Ascent, Impreza, Legacy, WRX
- Almost always uses a CR2032 battery
Flip key fob
- Metal key blade flips out with a button
- Buttons are on a thicker plastic body
- Common on mid-2010s Subaru models
- Often uses CR1620 or CR2025
Standard remote (separate from the key)
- Small rectangular remote with a simple metal key on its own
- Common on older Subarus (early 2000s and older)
- Frequently uses CR2025 or CR1620

If you’re unsure, check the back of the fob or open it carefully and look at the old battery – the size (CR2032, CR1620, CR2025) is printed right on it.

Why your Subaru model year matters

Subaru changed key fob designs and battery types over the years. That’s why model and year matter:

2015+ with push-button start (Outback, Forester, Crosstrek, Legacy, Impreza, WRX, Ascent)
- Typically use the smart key fob with a CR2032
2008–2014 models
- Often use flip keys or standard remotes with CR1620 or CR2025
Older than 2008
- Most use basic remotes, usually CR2025 or CR1620

Subaru models most likely to use CR2032, CR1620, or CR2025

Here’s a quick reference by battery type:

CR2032 Subaru replacement (most common today)
- Subaru Outback (2015–newer, especially 2018–2026)
- Subaru Forester (2014–newer, including 2018, 2019, 2020, 2026, 2022, 2026)
- Subaru Crosstrek (2013–newer, including 2020–2026)
- Subaru Ascent (2019–newer)
- Newer Impreza, Legacy, WRX with keyless access / smart key
CR1620
- Many older flip key Forester, Impreza, Legacy, Outback models (mid-2000s to early 2010s)
CR2025
- Some standard remotes and early flip keys on older Outback, Forester, Impreza, and Legacy

Once you know your fob style and model year, you can confidently buy the right Subaru key fob replacement battery and avoid guesswork.

Find the Correct Subaru Key Fob Battery

Before you pop the case open, you want the right Subaru key fob battery in your hand so you only do this once.

Most Common Subaru Key Fob Battery Types

Most Subaru key fobs in the U.S. use one of these coin batteries:

CR2032 – Most newer Subaru smart key / push-button start fobs
CR1620 – Many older small oval remotes
CR2025 – Some mid‑2010s remotes and flip keys

When people search “how to replace Subaru key fob battery,” 9 times out of 10 they’re buying a CR2032 Subaru replacement.

How to Confirm Your Subaru Battery Size

Don’t guess the size—confirm it in one of these ways:

Check the owner’s manual under “keys” or “keyless access battery replacement”
Look inside the fob – the old coin cell will be stamped CR2032, CR1620, or CR2025
Sometimes the plastic shell is labeled inside with the battery type

If you’re using an older 2‑button remote like the 2005–2008 Subaru Forester/Impreza/Legacy remote (same style as this NHVWB1U711 Subaru keyless entry remote), you’ll almost always be on a CR1620.

Quick Subaru Battery Reference (By Model – Typical, Not Guaranteed)

These are common patterns in the U.S. market (always double‑check yours):

Outback – 2015+ smart key: usually CR2032
Forester – 2014+ with keyless access: usually CR2032
Crosstrek – 2013–2017 often CR1620/CR2025, 2018+ smart key usually CR2032
Ascent – All years with smart key: usually CR2032
Impreza – Older remotes often CR1620, newer smart key: CR2032
Legacy – 2015+ smart key commonly CR2032
WRX – Flip key/older remote: CR1620/CR2025, newer smart key: CR2032

Again, treat this as a quick Subaru key fob battery size reference, not a substitute for checking your actual fob.

Matching Battery Brand and Specs

For best performance and range from your Subaru keyless entry battery:

Stick with major brands: Panasonic, Energizer, Duracell, Sony
Make sure the code matches exactly (CR2032 ≠ CR2025, even if they “almost fit”)
Avoid no‑name bulk packs; they drain faster and can cause “Subaru key fob not working after battery” issues
Look for fresh stock (recent manufacture date) from auto parts stores, big retailers, or reputable online sellers

Use the correct Subaru key fob battery type and a quality brand, and your fob should work reliably for years.

Tools and Supplies You Need Before You Start

Before you tackle a Subaru key fob battery replacement, get your tools and parts lined up so you don’t crack the case or damage the buttons.

Basic tools to open a Subaru key fob safely

For most Subaru smart keys, flip keys, and standard remotes, you’ll only need:

Small flathead screwdriver or plastic trim/pry tool
Soft cloth or microfiber towel (to protect the plastic)
New battery (CR2032, CR1620, or CR2025 depending on your fob)
Small tray or cup to keep the emergency key and any tiny parts in one place

If you don’t have a plastic pry tool, you can repurpose a plastic guitar pick or an old rewards card instead of metal to avoid gouging the case.

Recommended battery brands and where to buy them

For the best Subaru key fob battery life and range, I stick with name‑brand lithium coin cells:

Panasonic, Energizer, Duracell, Sony, Maxell
Look for “CR2032,” “CR1620,” or “CR2025” and “3V Lithium Coin” on the package
Avoid super-cheap bulk packs from unknown brands; they often die early or are under‑voltage out of the box

You can pick these up at:

Big-box stores (Walmart, Target)
Auto parts stores (AutoZone, O’Reilly, Advance)
Pharmacies (CVS, Walgreens)
Online marketplaces (Amazon) or specialty key/remote shops

How to avoid scratching or cracking your key fob case

Subaru key fob shells will crack if you pry in the wrong spot or use too much force. To keep the case clean and intact:

Wrap your flathead screwdriver tip with a layer of tape or a microfiber cloth
Only pry at the molded notch or seam where Subaru designed the fob to open
Apply light, even pressure—wiggle gently instead of twisting hard
Work on a clean, flat surface so you don’t drop and chip the fob

If you work on other brands too, it’s worth having a dedicated plastic key fob pry tool, similar to what’s used for OEM remotes like this 4‑button keyless entry fob.

Safety tips before changing a Subaru key fob battery

Treat Subaru keyless access batteries like any other small electronic part:

Keep batteries away from kids and pets—coin cells are a choking hazard
Don’t short the battery by touching both sides with metal tools
Avoid touching the flat sides of the battery with bare fingers; skin oils can reduce contact quality—hold it by the edges
Check polarity before closing the fob: the “+” side almost always faces up
Recycle the old battery properly at a battery recycling bin; don’t toss it in regular trash
If your hands are wet or greasy, wash and dry them first to protect the fob’s contacts and circuit board

Having the right tools and a quality Subaru key fob replacement battery ready up front makes the whole job cleaner, safer, and a lot less stressful.

Step-by-Step: How to Change a Subaru Smart Key Fob Battery (CR2032)

If you’ve got a newer Subaru with push-button start, your smart key almost always uses a CR2032 battery. Here’s exactly how to replace the battery in your Subaru key fob without breaking the case.

1. Remove the Emergency Key from the Fob

Flip the fob so the Subaru logo side faces down.
Look for the small release button or slider on the back/side of the fob.
Press/slide it and pull the metal key out at the same time.
Set the key aside somewhere safe so you don’t misplace it.

2. Open the Subaru Smart Key Fob Case (Without Damage)

With the emergency key removed, you’ll see a small groove or slot where the key was.
Use a small flathead screwdriver or plastic pry tool in that slot.
Gently twist—not pry hard—until the case starts to separate around the edges.
Work your way around the fob, lightly twisting until the two halves come apart.
Don’t rush it; forcing it is how people crack the plastic.

3. Take Out the Old CR2032 Battery Safely

Once open, you’ll see a round coin battery (CR2032) sitting in the holder.
Note which side is facing up (usually the “+” side faces up).
Use a fingernail or plastic tool to lift the edge of the battery out of the clip.
Avoid metal tools on the contacts if possible, and don’t bend the metal tabs.

4. Install the New CR2032 Battery (Correct Direction)

Grab a fresh CR2032 battery (name brands like Panasonic, Energizer, or Duracell tend to last longer).
Make sure the “+” side matches the same direction as the old battery.
Slide the battery under the retaining clip and press it down gently until it’s fully seated and flat.
Try not to touch the flat surfaces with your fingers—oil can reduce contact. If you do, just wipe it with a clean, dry cloth.

5. Close the Fob Case and Snap It Back Together

Line up the two halves of the Subaru key fob so the buttons and logo are in the right position.
Press around the edges firmly with your fingers until you hear/feel it snap together all the way around.
Reinsert the emergency key until it clicks back into place.

6. Test Your Subaru Key Fob Buttons and Remote Range

Stand a few feet from your Subaru and test:
- Lock
- Unlock
- Trunk/Rear hatch (if applicable)
- Remote start (if equipped and activated)
Then step back farther (20–30+ feet) to confirm the remote range feels normal.
If the range is weak or buttons don’t respond, open the fob again and check:
- Battery is the correct CR2032 type
- Polarity (+/-) is correct
- Case is fully closed and not pinching the circuit board

Once this is done right, you usually won’t have to replace the Subaru smart key fob battery again for 2–3 years, depending on how often you drive and where you store the keys.

Step-by-Step: Change an Older Subaru Key Fob Battery (CR1620 / CR2025)

Older Subaru key fobs are simple to work on as long as you know which style you’re holding and which battery it uses.

1. Identify Your Older Subaru Remote or Flip Key Fob

You most likely have an older-style fob if:

Your Subaru is roughly early 2000s–mid 2010s.
The key blade folds out (flip key) or you have a small rectangular remote with 2–3 buttons and a separate metal key.
There’s no push‑button start and no “smart keyless access” logo.

Most of these use CR1620 or CR2025 coin batteries. To confirm:

Look for tiny battery markings inside the case once it’s open.
Or check the “keyless entry” section in your owner’s manual for the exact Subaru key fob battery type.

2. Open the Older Subaru Key Fob (Flathead Method)

To open the case without wrecking it:

Use a small flathead screwdriver or plastic pry tool.
Find the seam running around the fob or a small slot near the key ring or side.
Gently twist the screwdriver in the slot and work your way around the case.
Don’t force it—if you pry too hard, you can crack the plastic or pop the buttons out of place.

Wrap a bit of tape around the screwdriver tip if you want extra protection against scratches.

3. Remove and Replace the CR1620 or CR2025 Battery

Once the fob is open:

Note the battery orientation before you touch it. In most Subaru remotes, the “+” side faces up.
Carefully slide the coin cell out with the screwdriver or your fingernail.
Avoid bending the metal contacts and avoid touching the new battery’s faces with bare fingers (oil can shorten battery life).
Match the replacement exactly:
- CR1620 → replace with CR1620
- CR2025 → replace with CR2025
Use a quality brand (Energizer, Panasonic, Duracell) for strong Subaru remote range and longer life.

4. Reassemble the Fob and Check the Buttons

When you’re ready to close it up:

Make sure the rubber button pad and circuit board are seated flat.
Align the two halves of the case and press firmly around the edges until they snap together.
Test the fob:
- Press Lock/Unlock near the car.
- Check from farther away to confirm the Subaru keyless entry range feels normal.
If the buttons feel mushy or don’t click, reopen the fob and reseat the pad and board.

With the right Subaru key fob replacement battery and a careful open‑and‑close, you can handle this DIY in just a few minutes and skip the dealer visit and labor cost.

Model-Specific Subaru Key Fob Battery Guides

Subaru Outback key fob battery change by year

Most Subaru Outback key fobs from about 2015–2026 use a CR2032 battery, especially if you have push-button start or “Keyless Access.” Older Outbacks with a simple remote key often use CR1620 or CR2025. As a quick rule:

2015+ Outback with smart key: CR2032
2005–2014 Outback remote/flip key: CR1620 or CR2025 (check the number printed on the old battery)

The opening process is the same as other Subaru smart keys: remove the metal key, twist gently in the slot, split the case, and swap the battery with the + side facing up.

Subaru Forester key fob battery replacement steps

For the 2019–2026 Forester, including Sport and Wilderness, you’re almost always dealing with a CR2032 smart key fob. On 2014–2018 models, some trims still use a separate remote with a CR1620/CR2025.
Basic process:

Slide the release, pull out the emergency key
Use that key or a flat tool in the side notch to pop the case
Swap in a fresh CR2032 (or matching size) without bending the contacts
Snap the case tight and test lock/unlock and remote start (if equipped)

Subaru Crosstrek smart key battery instructions

Most Subaru Crosstrek key fobs (2018–2026) with push-button start run a CR2032. Earlier XV Crosstrek models with traditional keys may use CR1620. To replace:

Remove the metal key from the bottom of the fob
Insert into the small slot and twist to open
Replace with a name-brand CR2032, positive side up
Close the case evenly to avoid gaps and test near the vehicle

Subaru Ascent key fob battery DIY guide

Every Subaru Ascent sold in the U.S. uses a modern smart key that takes a CR2032 Subaru replacement battery. DIY is straightforward:

Pull out the hidden emergency key
Gently pry the two halves apart at the groove
Swap the CR2032, avoiding fingerprints on the flat surfaces
Press the case back together until it fully clicks

If your Ascent fob is cracked or badly worn, you’re often better off dropping the guts into a new shell, similar to how you’d handle a worn GM/Honda style replacement fob housing.

Impreza, Legacy, and WRX key fob battery notes

For Impreza, Legacy, and WRX:

Most 2015+ smart key systems use CR2032
Older remote keys (especially 2008–2014) often use CR1620 or CR2025
WRX/STI models with flip keys typically hide a CR1620 inside the fob head

Always confirm the battery type printed on the old battery or in the owner’s manual before you buy.

Small design changes by model year to watch for

Subaru tweaks the key fob shell every few years, even when the battery type stays the same. Watch for:

Different case seams or pry points (some split at the side, others at the top)
Extra screws on older Legacy/Outback and early Impreza remotes
Remote-start add-on fobs that use a separate battery size
Logo side vs. button side opening – don’t force the wrong edge

If the case isn’t opening with light pressure at the marked notch, stop and recheck where the seam is. Forcing it is the fastest way to crack the shell or damage the internal board, which costs far more than a simple battery swap.

Common Mistakes When Replacing a Subaru Key Fob Battery

When you replace a Subaru key fob battery, a few small mistakes can kill a brand‑new battery or make the fob stop working. Here’s what to avoid:

1. Putting the Battery in Upside Down

CR2032, CR1620, and CR2025 batteries have a positive (+) side and a negative (–) side.

The + side almost always faces up in Subaru key fobs.
If you install it upside down, the fob will act completely dead, even with a fresh battery.
Always match the new battery orientation to how the old one was sitting.

2. Using the Wrong Battery Size or Thickness

Not every Subaru key fob uses the same battery type.

Forcing a CR2032 where a CR2025 or CR1620 should go can bend contacts or keep the case from closing right.
A battery that’s too thin can make the connection loose and cause random failures.
Double‑check the battery code stamped on the old cell or in your owner’s manual before you replace a Subaru key fob battery.

3. Forcing the Key Fob Case Open

Prying too hard is an easy way to:

Crack the plastic shell
Break internal clips
Damage the rubber seal (on some push‑button start fobs)
Always use the small notch on the case and a thin plastic tool or small flathead. Gentle twisting is enough to open a Subaru key fob—if you’re forcing it, you’re doing it wrong.

4. Touching Battery Contacts With Fingers or Metal Tools

Skin oils and metal tools can cause poor contact or corrosion over time.

Try not to touch the flat surfaces of the new battery. Hold it by the edge.
Avoid scraping the contacts with a screwdriver.
If you do touch the battery, wipe it gently with a clean, dry cloth before installing.

5. Ignoring Dirty or Corroded Contacts

If your Subaru key fob still acts weak after a new battery, take a quick look inside:

Dull, green, or white buildup on contacts can block power.
Gently clean with a cotton swab and a tiny bit of isopropyl alcohol, let it dry fully, then reassemble.

If the board or contacts look severely damaged or corroded, the problem is bigger than a battery—at that point, a replacement fob or professional help is usually cheaper than fighting an unreliable remote.

Troubleshooting a Subaru Key Fob That Still Doesn’t Work

If you replaced the Subaru key fob battery and it’s still not working, walk through these quick checks before you spend money at the dealer.

1. Check Battery Orientation & Fit

Most Subaru key fobs use a CR2032, CR2025, or CR1620 coin battery. If it’s in backwards or not seated right, the fob won’t power up.

Make sure the “+” side is facing the same direction as the old battery (usually up).
Confirm the battery sits flat and snug in the holder—no wobble, no tilt.
Double-check you’re using the correct Subaru key fob battery type, not “something close.”

If the case doesn’t close cleanly or feels forced, open it back up and reseat the battery.

2. Clean Subaru Key Fob Contacts Safely

Dirty or oxidized contacts can block power even with a fresh battery.

Do this carefully:

Remove the battery.
Use a cotton swab with 70%+ isopropyl alcohol to gently wipe the metal contacts.
Let everything air dry fully (no heat, no hairdryer).
Do not scrape with a screwdriver or knife—this can damage the board.
Reinstall the battery and test again.

3. When It’s the Car, Not the Key Fob

Sometimes the problem isn’t the fob at all:

Weak car battery: If your Subaru cranks slowly, has dim lights, or random electrical glitches, the car battery might be low and not “seeing” the key reliably.
Interference: Heavy radio interference (big parking garages, near radio towers, or crowded lots) can cut remote range.
Locked-out mode: Some models can disable keyless entry if the alarm has triggered or the battery was disconnected—try unlocking with the physical key, then start the car.

If other electronics on the car act strange, have the vehicle battery tested at an auto parts store.

4. Signs the Circuit Board Is Damaged

If the Subaru key fob still doesn’t work after a known-good battery and cleaning, the internal electronics might be failing:

Buttons feel mushy or don’t “click.”
Case has been dropped hard, crushed, or soaked in water.
Range is extremely short (you need to be right next to the car).
Some buttons work, others don’t, even with a fresh battery.

In these cases, you’re often looking at repair or full key fob replacement, not just a battery.

5. Do You Need to Reprogram After a Battery Change?

For most late-model Subaru Outback, Forester, Crosstrek, Ascent, Impreza, Legacy, and WRX, you do not need to reprogram the key fob after a simple battery swap. The car stores the programming, not the battery.

You might need reprogramming when:

You’re using a brand-new or used replacement fob.
The fob was previously erased from the car’s memory.
The car’s ECU or security system was replaced.

Programming usually requires dealer software or a professional locksmith.

6. When to Call a Dealer, Locksmith, or Order a New Fob

If you’ve:

Verified correct battery size and orientation
Cleaned contacts properly
Confirmed the car battery is healthy
Tried locking/unlocking with the emergency key

…and the Subaru key fob still fails, it’s time to get help.

Your options:

Dealer – Best if you want OEM-only parts, full warranty, and key fob programming handled for you. It will usually cost more, especially compared to doing your own DIY key fob battery replacement.
Automotive locksmith – Often cheaper than the dealer, can cut keys and program fobs on-site.
Order a replacement key fob – Once you have a compatible fob, you’ll still need programming, similar to what you’d do for other brands like a replacement Cadillac key fob battery and remote setup.

If the Subaru key fob won’t unlock doors or start the car after all these steps, don’t keep forcing the case open. At that point, getting a pro involved will save time, frustration, and possibly the cost of a full new fob.

How to Make Your Subaru Key Fob Battery Last Longer

If I can help you stretch a Subaru key fob battery from 1 year to 3+ years, that’s a win. Most Subaru key fobs use CR2032, CR2025, or CR1620 batteries, and how you use and store the fob has a huge impact on battery life.

Everyday habits that drain your key fob battery faster

These small habits kill Subaru key fob batteries early:

Keeping the fob next to the car overnight (in the garage or hanging right by the car) – the car and fob keep “talking,” which drains the battery.
Stuffing the fob in tight pockets or bags where buttons get held down (panic, lock, remote start). Constant signals = faster drain.
Leaving the fob near electronics like Wi‑Fi routers, laptops, or wireless chargers – they can cause the fob to keep transmitting.
Using remote start or lock/unlock from long distances over and over just to “check” the car.

If you have keyless access or push-button start, be extra careful about where you leave the fob when you’re home.

Ideal storage habits at home and work

Set up a “home base” for your Subaru key fob:

Keep the fob 15–20 feet away from the car when parked at home or work.
Use a tray, hook, or drawer by the front door that’s not on the same wall as the garage.
If you have a spare Subaru key fob:
- Store it with no pressure on the buttons (not under heavy items, not in a jammed drawer).
- Consider a small pouch or box to keep dust and moisture off the contacts.

These simple habits alone can add months of life to a CR2032 Subaru replacement battery.

Typical Subaru key fob battery lifespan

In normal U.S. daily use:

Smart key / push-button start fobs (CR2032): about 2–3 years
Older standard remote or flip keys (CR1620 / CR2025): about 1.5–2.5 years
Heavy use (city parking, remote start, multiple drivers) will shorten that.

If you’re burning through batteries every few months, that’s a red flag there’s a usage, storage, or fob issue.

Use low-battery warnings to plan ahead

Newer Subaru models will usually show:

A “Key fob battery low” message on the dash, or
Shorter remote range and weaker response on lock/unlock

The smart move when you see the warning:

Replace the battery within 1–2 weeks, not when it totally dies.
Pick up a name-brand CR2032 (Energizer, Panasonic, Duracell, etc.) from a local store or auto parts shop so you’re not stuck last-minute.

When to replace the battery before a trip

If you’re about to:

Take a road trip
Drive in extreme cold or heat
Park at an airport for several days

Then:

Proactively replace any Subaru keyless entry battery that’s 2+ years old or already showing weak range.
Keep one spare CR2032 or your Subaru key fob battery type in your luggage or at home, not loose in the hot car.

Planning a simple key fob battery replacement before a long drive is far cheaper and easier than dealing with a dead fob in a hotel or airport parking lot.

Subaru Key Fob Battery FAQ

What battery does my Subaru key fob use by model and year?

Most newer Subaru key fobs (Outback, Forester, Crosstrek, Ascent, Impreza, Legacy, WRX from about 2015–2026) use a CR2032 coin battery.
Some older remotes and flip keys use CR1620 or CR2025.
Always confirm by:

Checking the owner’s manual under “keyless entry” or “key fob battery”
Opening the fob and reading the size printed on the old battery (CR2032 / CR1620 / CR2025)

Do I need to reprogram my Subaru key fob after changing the battery?

In almost all cases no. If the same key worked before and you only swapped the battery, it should work immediately. If it doesn’t, the issue is usually:

Battery upside down
Wrong battery type
Poor contact with the terminals

Why is my Subaru key fob not working after a new battery?

Common causes:

Battery installed backwards (positive side should match the “+” in the fob)
Wrong size (CR2032 vs CR2025 vs CR1620)
Battery not fully seated or clip not touching it
Dirty or bent metal contacts
Cheap battery that’s weak right out of the package
Reseat the battery, clean contacts with a cotton swab and a bit of rubbing alcohol, then test again.

How much does dealer Subaru key fob battery replacement cost?

At most Subaru dealers in the U.S., key fob battery replacement runs about:

$20–$50 total (battery + labor)
Doing it yourself with a name‑brand CR2032 or CR1620 usually costs $3–$10.

Can I use any CR2032 battery brand in my Subaru fob?

You can use any quality name‑brand CR2032 that matches the specs (3V lithium coin cell), like Panasonic, Energizer, or Duracell. Avoid unbranded super‑cheap packs; they often have:

Shorter life
Inconsistent voltage
Higher risk of early failure

How far should my Subaru remote work after a fresh battery?

On a healthy Subaru key fob battery, you should expect roughly:

60–100 feet in open space for lock/unlock
Shorter range in parking garages, around buildings, or with interference
If your Subaru remote range is weak right after a new battery, recheck installation and battery quality.

Can I drive if my Subaru key fob battery is low?

Yes, in most Subaru push‑button start models:

If the battery is low, you can usually still start by holding the fob against the start button
But you should replace the battery ASAP so you don’t get stranded if it dies completely.

What if I lose the emergency key while changing the battery?

If you lose the metal emergency key:

Your fob will still work electronically, but you can’t unlock the door manually if the car battery or fob battery dies
You’ll need a replacement key blade cut by a dealer or locksmith, which is cheaper than replacing the whole fob.

Can extreme heat or cold kill my Subaru fob battery early?

Yes. Extreme temps are hard on any Subaru keyless entry battery:

Heat (hot car in summer) speeds up chemical breakdown
Deep cold (below freezing for long periods) can temporarily drop voltage
Try not to leave your key fob sitting in a hot car for days at a time.

Is it safe to keep a spare Subaru key fob battery in the car?

It’s better to keep spare CR2032 / CR1620 / CR2025 batteries at home, not in the vehicle:

Heat inside the car can shorten shelf life
If your battery dies while you’re out, it’s often your car that’s hard to access, not your house
I recommend keeping a spare in your wallet, bag, or at home near where you hang your keys.