Skip to content

Mk4FL Car Key Battery

Featured Replies

I have only had the car for 2 months, and the dash display is saying that I need to replace the battery already.

Is this normal?

Hopefully it's just the first battery that was substandard and if I buy Duracell or similar in the future, they will last longer.

I can't help thinking that the rapidly flashing red light on the key can't be helping... (I have KESSY / keyless entry)

13 hours ago, Juniperz said:

I have only had the car for 2 months, and the dash display is saying that I need to replace the battery already.

Is this normal?

Hopefully it's just the first battery that was substandard and if I buy Duracell or similar in the future, they will last longer.

I can't help thinking that the rapidly flashing red light on the key can't be helping... (I have KESSY / keyless entry)

hi

two months is poss a bit short, but as you don't know the history of the key, but one thing to do is get a RFI pouch and keep

it in there, But I have found the batteries from Screwfix and they reasonably cheep and they last about 6 months.

But one thing I have found is replace both batteries at the same time   

  • Author

Thanks.  RFID pouch looses the point of having KESSY though...

This generation of KESSY uses UWB so should be resistant to the relay attacks that have been a major problem for keyless entry.

https://www.skoda-storyboard.com/en/skoda-world/the-approach-of-the-keyless-age/  -

Quote

UWB box protects against signal extension
The new generation of keyless entry systems offers one ingenious safety feature: protection against what’s known as “signal extension”. To this day, we still occasionally come across reports of thieves trying to steal a parked car by amplifying (or “extending”) the signal of the key needed to open the car. The new OCTAVIA and electric ENYAQ iV models are already equipped with something called a UWB box that prevents this. UWB stands for Ultra Wide Band, and the device works on the principle of signal time-of-flight verification. The signal travels at the speed of light, so the UWB box sends a signal to the key and waits for a response, which must come within a certain time. If the signal is extended, it will never make it in time – it’s a physical impossibility.

 

The flashing red light means that the key can "see" the car and so the battery will be in use.

Once out of range the key should stop flashing, storing the key in an RFI pouch or a metal tin should prevent this.

 

Energizer batteries at rated at 240mAh, duracell at 225mAh with most others being at 210mAh, using a genuine branded battery will give you the best longevity.

My car is just on 2 years old (from build date) and the message just came up on Friday, I've now replaced with energizers in all 3 keys. The keys are kept in RFI pouches and get rotated once a quarter to achieve even wear.

Lately I've noticed a very faint even 'ticking' sound coming from the car when all is quiet in the garage, it stops on unlocking the car. I'm not sure what it's related to but haven't noticed it before.

  • 4 months later...
  • Author

This was my original thread, so I may as well add to it.

3 weeks ago, I returned to my car late in the evening and was unable to unlock it keylessly or with the buttons on the key. Not a squeak, no red light on the key. I remembered that the door keyhole was concealed in trim behind the door handle, and managed to unlock the car, but the alarm sounded constantly all the time the door was open. I held the key near to the steering column, the cubby by the handbrake switch, the cubby ahead of the gear lever in the hope that there was some kind of proximity sensor, but nothing.

The noise wasn't that embarrassing because it was a sports centre car park away from houses, but I was stranded. If my wife hadn't been out of the country I would have asked her to drive the spare key to me. Luckily one of the people I have been playing sport with, saw I wasn't heading off promptly and offered to help. Eventually we concluded that the best thing would be for him to drive me home (20 minutes), collect the spare key, drive me back, and then we could both drive home. Without him, I'd have been completely stuck.

The issue - absolutely no warning from the car that the battery was in need of replacement. Can I get Skoda to pay for the nice bottle of red that I felt I should give to the helpful acquaintance? This was a Duracell battery, not an eBay cheapy.

If I have gained entry to the car with the physical key, is there a special place where it can be placed that would have enabled me to drive the car?

2 hours ago, Juniperz said:

This was my original thread, so I may as well add to it.

3 weeks ago, I returned to my car late in the evening and was unable to unlock it keylessly or with the buttons on the key. Not a squeak, no red light on the key. I remembered that the door keyhole was concealed in trim behind the door handle, and managed to unlock the car, but the alarm sounded constantly all the time the door was open. I held the key near to the steering column, the cubby by the handbrake switch, the cubby ahead of the gear lever in the hope that there was some kind of proximity sensor, but nothing.

The noise wasn't that embarrassing because it was a sports centre car park away from houses, but I was stranded. If my wife hadn't been out of the country I would have asked her to drive the spare key to me. Luckily one of the people I have been playing sport with, saw I wasn't heading off promptly and offered to help. Eventually we concluded that the best thing would be for him to drive me home (20 minutes), collect the spare key, drive me back, and then we could both drive home. Without him, I'd have been completely stuck.

The issue - absolutely no warning from the car that the battery was in need of replacement. Can I get Skoda to pay for the nice bottle of red that I felt I should give to the helpful acquaintance? This was a Duracell battery, not an eBay cheapy.

If I have gained entry to the car with the physical key, is there a special place where it can be placed that would have enabled me to drive the car?

Between the front cup holders and the arm rest you have a small cubby hole that is the perfect size for the fob... The reason being because it's where you are supposed to place the fob whilst driving. 👍

With regard your comment about the pouches defeating the object of KESSY..... You're only supposed to use the pouch when not using the car... I just remove the key from the pouch when i head towards the car then put it back in the pouch when it's locked and I'm walking away from the car..... Their purpose is to stop criminals scanning your fob when you have put them away in a drawer etc.... whilst you are asleep in bed and then just getting in your car and stealing it. But they also mean the fob goes into it's sleep mode and conserves the battery when not in use.

Edited by WaveyDavey

FWIW Panasonic batteries appear to last the best, there have been a few posts on this issue and that was the consensus.

I now buy them by the box as my motorcycle takes the same battery for it's key, though they last longer in that than in the Skoda!

Depending on use, around 6 months seems to be the average battery life for good quality batteries.

  • Author
On 28/03/2025 at 00:43, WaveyDavey said:

Between the front cup holders and the arm rest you have a small cubby hole that is the perfect size for the fob... The reason being because it's where you are supposed to place the fob whilst driving. 👍

Perfect size for a fob unless you keep your key on a key ring, with your other keys...

On 28/03/2025 at 00:43, WaveyDavey said:

With regard your comment about the pouches defeating the object of KESSY..... You're only supposed to use the pouch when not using the car... I just remove the key from the pouch when i head towards the car then put it back in the pouch when it's locked and I'm walking away from the car..... Their purpose is to stop criminals scanning your fob when you have put them away in a drawer etc.... whilst you are asleep in bed and then just getting in your car and stealing it. But they also mean the fob goes into it's sleep mode and conserves the battery when not in use.

As above, my house keys are with my car key, in my trouser pocket so that when I leave the house, I have my keys so I am never locked out of the house, and I can always drive my car.

As much further above, this generation of KESSY is resistant to the criminals scanning attack ( https://www.skoda-storyboard.com/en/skoda-world/the-approach-of-the-keyless-age/ specifically "UWB box protects against signal extension )

But all of this misses the point - why did the car just dump be stranded in the middle of the night without any warning that the key battery might die soon?

Edited by Juniperz

Create an account or sign in to comment

Recently Browsing 0

  • No registered users viewing this page.

Important Information

Welcome to BRISKODA. Please note the following important links Terms of Use. We have a comprehensive Privacy Policy. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.

Account

Navigation

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.