These instructions apply to the Honda CR-V Mk5 (RW/RT) 2018-2023.
For other models, please choose your vehicle here.
If the remote on your Honda CR-V Mk5 (RW/RT, 2018–2023) is getting weak — short range, fussy keyless entry, or a “key battery low” message — the coin cell needs renewing. The CR-V key takes either a CR2032 or a CR1620 depending on the fob, so check the old cell before you buy. It is a two-minute job on the kitchen table, and it does not disturb the key’s coding — the fob stays paired to your CR-V, so there is no dealer visit for a simple battery change.
How to Tell the Fob Battery Is Dying
A smart key on the CR-V usually fades gradually rather than dying outright. The warning signs are consistent:
- Shrinking range — you have to stand closer to the car than you used to before the doors respond.
- Multiple presses needed, or it only works when pointed directly at the car.
- Keyless entry only up close — the handle responds only when the key is almost touching it, because a proximity key stays awake and drains faster than a button-only remote.
- A “key battery low” message in the driver display.
- Worse in the cold — a tired coin cell loses voltage on a frosty morning and can seem dead, then partly recover once it warms.
As a rough guide a button-only remote cell lasts around two to four years, while a keyless smart key that wakes each time you approach is nearer a year or two. If yours is a few years old, a fresh cell is the cheapest first move.
Which Cell Your Key Takes
The CR-V Mk5 shipped with more than one fob, and they do not all use the same cell. Open the fob and read the marking on the old cell before you buy: it is usually a CR2032 on the keyless smart key, or a CR1620 on some remotes. Both are 3 V lithium coin cells, but they are different diameters and are not interchangeable — a CR1620 will rattle loose in a CR2032 holder and a CR2032 simply will not fit a CR1620 one. Match exactly what comes out, and buy a branded cell; cheap no-name cells often read low from new and bring the weak-range problem back within months.
How to Replace the CR-V Mk5 Key Battery
- Slide out the emergency key. Push the release latch on the fob and withdraw the metal blade — this frees the blade and opens the slot you use to split the case.
- Split the case. Use the slot the blade leaves, or slip a small flat screwdriver into the seam, and gently work the two halves apart. It clips together, so it needs a firm but careful twist rather than force.
- Note the type and orientation. Read whether it is a CR2032 or CR1620 and see which way up it sits before you lift it out.
- Lift out the old cell and fit the matching new one the same way up, handling it by the edges only to keep skin oil off the flat faces.
- Clip the case shut until the seam closes evenly all round, then slide the emergency blade back home.
- Test lock and unlock from a normal distance and check keyless entry at the handle.
⚠️ Watch the polarity. The printed + side must face the same way the old cell did. Forcing a cell in upside down can bend the spring contact and leave the fob dead even with a brand-new battery.
Check It Worked
Stand back a normal distance and lock, then unlock — the range should be back to full. Walk up to the car with the key in your pocket and try the handle to confirm keyless entry responds without you reaching for the fob. If a “key battery low” message was showing, it typically clears by itself after the next drive cycle once the car sees a healthy key.
If a Fresh Cell Doesn’t Fix It
- Re-open the fob and confirm the cell is seated flat and the right way up — a cell sitting proud of its clip will not make contact.
- Confirm the type — it is easy to fit a CR2032 where the fob actually wanted a CR1620 (or vice versa); match what you removed.
- Wipe the contacts inside the fob with a clean dry cloth or cotton bud to clear any film or corrosion.
- Backup start: if keyless is slow or dead, hold the smart key flat against the start button as you press it — the car reads the key directly and starts, and re-syncs from there.
- Rule out the car’s 12 V battery — if the whole car is slow to wake, not just the key, the vehicle battery may be the real problem.
New Key or Spare — Why It’s a Dealer Job
A battery change keeps the key’s coding, which is why it works the moment you clip the case back together. A brand-new or replacement smart key is different: it has to be coded to your CR-V’s VIN through the immobiliser with diagnostic equipment, so it is a job for a Honda dealer or an auto locksmith — there is no owner sequence to pair a new transponder. If you keep a spare in a drawer, refresh its battery every few years too; a spare that sits unused still drains slowly, and you do not want to find it flat on the day you need it.
Frequently Asked Questions
What battery does the Honda CR-V Mk5 key take?
Either a CR2032 or a CR1620 3 V lithium coin cell, depending on which fob you have — the keyless smart key is usually CR2032 and some remotes take CR1620. Open the fob and match the code stamped on the cell you remove.
Which way up does the cell go?
Match the orientation of the cell you took out — the printed + face normally sits upward. Note it before lifting the old one so you fit the new one the same way and avoid bending the contact.
Do I need to reprogram the key after changing the battery?
No. A battery swap does not affect pairing, so the key works straight away. Reprogramming is only needed for a lost or additional key, which the dealer codes to the car.
How long should the new battery last?
Roughly two to four years for a button-only remote, and closer to a year or two on a keyless smart key that wakes every time you approach the car. Cold weather and heavy keyless use shorten it.
The key still won’t work after a new cell — what now?
Re-check polarity and seating, make sure you fitted the correct type (CR2032 vs CR1620) for your fob, and wipe the contacts. If it is still weak, the vehicle’s own 12 V battery may be low — test that before blaming the key.
Can I drive the CR-V if the fob battery is dead?
Yes. Use the emergency blade in the fob to unlock the driver’s door, then hold the smart key flat against the start button as you press it — the car reads the key directly and starts.
To clear a service reminder after maintenance, see our CR-V Mk5 service reset guide. For warning lights, look up the code on autodtcs.com.
Independent guide — not affiliated with Honda. Always follow your official service manual and safety precautions. Read our full disclaimer.