Porsche Key Fob Battery Replacement: CR2032 for 911, Cayenne, Macan, Panamera and Taycan
Porsche keys take one CR2032 battery, whether it is the 2005 to 2012 key with the fixed blade (997 911, 987 Boxster and Cayman, first Cayenne), the 2009 to 2018 key with the emergency blade hidden inside (991 and 981, 958 Cayenne, first Panamera, first Macan), or the current key on the 992, 718, Cayenne, Panamera, Macan and Taycan. To open the newer keys, press the release and pull out the emergency blade, then put its tip into the slot it came from and lever the cover off. Fit the new cell the same way round as the old one. No reprogramming is needed.
A Porsche key is an expensive piece of plastic, which is a good reason to open it the right way rather than at the seam with a kitchen knife. The battery itself is ordinary: the same CR2032 that goes in a Volkswagen or Audi key, because Porsche keys come from the same supplier. This guide shows where each generation of Porsche key opens, which cells to avoid, how to start the car if the key is already dead, and what to check if the car still does not see the key afterwards.
Which battery your Porsche key fob takes
Find your key in the table. The FCC ID printed on the back of the fob tells you which family it belongs to, but for Porsche the answer in the last column is the same for every key made since the mid-2000s.
| Key style | Typical FCC ID | Common on | Battery |
|---|---|---|---|
| Older remote head key (buttons on the key head, fixed blade) | KR55WK45032, KR55WK50138 | 996 911 and 986 Boxster 1999 to 2004, 997 911 and 987 Boxster and Cayman 2005 to 2012, Cayenne 2003 to 2010 | CR2032 (a few early 996 and 986 keys take a CR2025, so read the code) |
| Key with hidden emergency blade, 2009 to 2018 style | KR55WK50138, KR55WK50137, 7PP959753 | 991 911 2012 to 2019, 981 Boxster and Cayman 2013 to 2016, 718 2017 to 2019, Cayenne 2011 to 2018, Panamera 2010 to 2016, Macan 2015 to 2018 | CR2032 |
| Current key with hidden emergency blade | IYZPK2, IYZPK3, 9Y0959753 | 992 911 2020 on, 718 2020 on, Cayenne 2019 on, Panamera 2017 on, Macan 2019 on, Taycan 2020 on | CR2032 |
If you open the key and find a CR2025 in a 2005 or newer key, someone fitted the wrong cell last time. The holder is designed for the 3.2 mm thick CR2032 and a thinner cell sits loose and makes poor contact. If the code on the old cell is unreadable, the owner’s manual lists the type in the section on the vehicle key.
The code tells you the size: the first two digits are the diameter in millimetres and the last two are the thickness in tenths of a millimetre, so a CR2032 is 20 mm wide and 3.2 mm thick while a CR2025 is the same width but thinner. A thinner cell in the same holder makes poor contact and causes the random dropouts people blame on the car. Our key fob battery size chart lists every size by brand.
What you need
- One new CR2032 from a name brand (Panasonic, Energizer, Duracell, Murata, Varta or Porsche branded all work)
- A plastic pry tool or a small flat-blade screwdriver with the tip wrapped in tape
- A clean table and good light, so a dropped battery does not vanish and the painted crest on the key does not get scratched
Avoid rechargeable cells such as LIR2032. They have the right shape but a higher voltage, and they are not what the key is designed for. A branded 3 V lithium cell with a date well into the future is all you need.
Changing the battery in a Porsche key with a hidden emergency blade
This covers every Porsche key from about 2009 onwards: the 991 and 981 era key and the current key used on the 992, 718, Cayenne, Panamera, Macan and Taycan. They open the same way.
Press the small release button on the side or back of the key and pull the metal key blade straight out. You will use its tip as the pry tool.
Look into the opening the blade came from. There is a small notch between the back cover and the body. Push the tip of the blade or a taped screwdriver into that notch and lever gently. The back cover lifts off from that end. Do not pry around the outside seam or under the painted crest.
Before you touch the battery, look at which side shows. On most Porsche keys the + side with the code printed on it faces up, towards the back cover, but take a photo so there is no guessing later.
Use a plastic tool or the tip of the blade at the small cut-out beside the battery to lever it up, and lift it out by the edge. Do not slide a metal tool across the circuit board.
Hold the new cell by its edges and press it into the holder the same way round as the old one. It should sit flat and click under the retaining tab. A battery that rocks or stands proud is the wrong size.
Line the cover up, press it on until the seam is flush all round, slide the emergency blade home until it clicks, and press lock and unlock. The indicators should flash and the small LED on the key should blink with each press.
If the rubber button pad lifted with the cover, lay it back in the body first, buttons facing out, and check it is sitting in its groove before you close the case. A pinched pad is why buttons feel mushy after a battery change.
Changing the battery in an older Porsche remote head key
This is the 1999 to 2012 key where the buttons sit on the plastic head of a fixed metal blade, used on the 996, 986, 997, 987 and the first Cayenne.
- Find the release. On the 997 and 987 key there is a small catch on the side of the head; slide it and the battery cover on the back lifts off. On the 996 and 986 key, and the first Cayenne key, look for a notch on the seam of the head opposite the blade and twist a plastic tool in it, or on the earliest keys remove the small Phillips screw first.
- Work the cover off slowly rather than forcing one spot. The plastic on these keys is twenty years old and brittle.
- Note which way the battery faces, then lever it out from the cut-out at its edge.
- Press in the new cell the same way round, check the rubber button pad is seated, and press the cover back on until it clicks. If the key has lost its pairing after a long time without power, hold it next to the ignition and turn the key to position 1 for a few seconds; the car re-synchronises the remote.
The transponder chip that lets the car start is sealed in the key head and does not use the battery. So even with a completely dead remote the key still turns the ignition and starts the engine; you just have to unlock the door with the blade.
3V lithium CR2032 coin cell
Every Porsche key since the mid-2000s takes a CR2032. Buy a name brand in a small multi-pack and keep the spares in the glove box, not loose in the key.
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Do you need to reprogram a Porsche key after a battery change?
No. The pairing between the key and the car is stored in memory that does not depend on the battery, so a Porsche key keeps working as soon as a fresh cell goes in. If the instrument cluster showed Key battery low or Replace key battery, it clears after the next start or two. The only exception is the oldest remote head keys, which can lose synchronisation after weeks without power; turning the key in the ignition once fixes that, as described above.
If the car still does not see the key
First, get moving. On a Porsche with an ignition slot, including Cayenne, Panamera and Macan models with Entry & Drive up to 2018, push the key into the slot and turn it as normal; the slot reads the chip directly. On the current cars without a slot (992, 718 from 2020, Cayenne from 2019, Panamera from 2017, Macan from 2019, Taycan) there is an emergency reading point: hold the key directly against the ignition switch or the marked spot on the steering column shown in the owner’s manual, hold the brake and turn the switch or press Start. The emergency blade opens the driver’s door if the remote lock does not respond; on newer cars the lock cylinder is under a cover on the handle that pops off with the blade.
Then work through the usual causes, in order of how often they turn out to be the problem:
- Wrong size. A CR2025 or CR2016 in a CR2032 holder makes patchy contact and the key works one day and not the next. Compare the code on the new cell with the old one.
- Upside down. If the key does nothing at all and the LED does not flash, open it and turn the battery over.
- Bent or dirty contact. The spring contact can be flattened by prying. Lift it gently with a plastic tool and clean it with a dry cotton bud. See how to clean key fob battery contacts.
- Tired new battery. Cells that sat in a drawer or came from an unbranded multi-pack can be flat out of the packet. Try a second one from a fresh pack.
- The car’s 12 V battery. A Porsche that sits for weeks is hard on its battery, and a low battery is a far more common cause of a no-start than the key. See can a bad car battery cause key fob problems.
- Damage inside the key. A key that has been dropped hard, through a wash, or left on a hot dashboard can have a cracked solder joint or corroded board. A locksmith can test whether it still transmits.
If the buttons work but the car does not respond, the full checklist is in key fob not working after a battery replacement.
What it costs
A Porsche dealer will fit a battery while you wait, and many do it free for a car they service. The larger figures only apply if the key itself has to be replaced. Porsche keys are ordered against the VIN and programmed with factory tools, so a lost key is one of the more expensive to replace in the business; a five-minute battery change is the cheap way to keep that from ever being necessary.
How long the new battery will last
An older remote head key only transmits when you press a button, so a CR2032 in one typically lasts three years or more. A key for a car with Entry & Drive or Comfort Access listens for the car and answers whenever you touch a door handle, so expect one to two years, less if the key lives within a few metres of the car overnight. Cold weather and carrying the key loose with things that press the buttons both shorten that. More detail is in how long key fob batteries last.
Safety: keep coin batteries away from children and pets
A swallowed coin cell can cause serious internal burns within hours. Keep spares and the old cell out of reach, and dispose of old batteries at a drop-off point rather than in household waste. If you think a child has swallowed a battery, go to the emergency room straight away and call the National Battery Ingestion Hotline at 1-800-498-8666, or Poison Help at 1-800-222-1222.
Frequently Asked Questions
Every Porsche key since the mid-2000s takes a single CR2032 3 V lithium coin cell, including the 911, 718, Cayenne, Macan, Panamera and Taycan keys. A few early 996 and 986 keys take a CR2025, so confirm with the code on the old battery.
Press the release and pull out the emergency key blade, then push the tip of the blade or a taped flat screwdriver into the notch inside the slot it came from and lever gently. The back cover lifts off. Do not pry at the outside seam or under the crest.
No. Porsche keys keep their pairing without battery power. The key works as soon as the new battery is in, and the key battery warning clears after the next start or two.
On a car with an ignition slot, push the key in and turn it as usual. On the current cars without a slot, hold the key against the ignition switch or the marked emergency reading point on the steering column shown in the manual, hold the brake and start. Use the emergency blade to unlock the driver’s door.
Not in a key designed for a CR2032. It will fit the holder and may work for a while, but it is thinner, so the contact is poor and the key becomes unreliable. Use a CR2032.
The car usually needs a start cycle or a short drive to update. If it stays on, check that the new cell is a CR2032 from a fresh pack, the right way up, and that the spring contact in the key is not flattened.