Replace Key Battery Message

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Retali
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Replace Key Battery Message

Post by Retali »

Hello guys as the title suggests, i get this message on screen.
I already replaced the key battery 3 times, 2 duracell batteries and one Renata.
But i keep getting on screen this message.
Is my key kapputt or is just a random message that at some point will be removed on its own ?

Btw my air leak problems were caused because of map sensor plugs that would not lock entirely,
they would click etc but if you would put enough force on your hand they would be moved. It was something i noticed by accident.
So i guess in corners or change of gears the weight of the engine would slightly move
the plugs and the pin connectors would lose contact lol.
RUM4MO
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Re: Replace Key Battery Message

Post by RUM4MO »

I've always done what VW Group marques do and that is always only ever fit Panasonic batteries, might use Duracell elsewhere as in small torches/flashlights, but never in car keys.

Renata, is that not just a brand that gives you what you have paid, which is not a lot?
2226
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Re: Replace Key Battery Message

Post by 2226 »

I had that issue too quite a few months back.
Changed battery, turned key and it still complained.
Just had to press the unlock button a couple of times when the key was turned to accessory.
Basically just fiddle around with the buttons until the thing shuts up.
Retali
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Re: Replace Key Battery Message

Post by Retali »

RUM4MO wrote: Tue Dec 09, 2025 9:37 am I've always done what VW Group marques do and that is always only ever fit Panasonic batteries, might use Duracell elsewhere as in small torches/flashlights, but never in car keys.

Renata, is that not just a brand that gives you what you have paid, which is not a lot?
I read in other places that Renata was better than duracell regarding the key fobs , that's why i mentioned using it. Also Renata lithium 3v batteries are more expensive than panasonic ones, regarding the price you mentioned.
I will try to find a panasonic one, thank you.
Last edited by Retali on Wed Dec 10, 2025 7:05 am, edited 1 time in total.
Retali
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Re: Replace Key Battery Message

Post by Retali »

2226 wrote: Tue Dec 09, 2025 10:47 am
Just had to press the unlock button a couple of times when the key was turned to accessory.
Thanx, but what do you mean "turned to acessory" ?
I tried this aswell (without batteries aswell lol ).
2226
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Re: Replace Key Battery Message

Post by 2226 »

I mean key turned, but engine not started.
Retali
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Re: Replace Key Battery Message

Post by Retali »

2226 wrote: Wed Dec 10, 2025 1:44 pm I mean key turned, but engine not started.
thsnx!
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ciclo
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Re: Replace Key Battery Message

Post by ciclo »

I used to use genuine Panasonic batteries until I discovered Maxell.
The physical store didn't have Panasonic, so I was forced to buy another brand, a blister pack of Maxell, they are supreme!
Worked perfectly for the 6R and various remote control models, and also for the Golf 7.5, which is quite finicky about the remote battery.
scott18T
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Re: Replace Key Battery Message

Post by scott18T »

I had the same issue after replacing the key fob batteries, the way I managed to clear the message,
was to disconnect the main battery for a couple of minutes.
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ciclo
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Re: Replace Key Battery Message

Post by ciclo »

In my experience, I can only conclude that the software dedicated to this message is a bit sluggish/slow in understanding, so depending on non-specific factors, different possible solutions can be found.
The positive thing is that everyone ends up finding their own solution to this non-important 'issue'.

It was never mentioned that the car does not start/open due to having only this message on the instrument panel/infotainment system (without other added problems).
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Re: Replace Key Battery Message

Post by RUM4MO »

Further to my comment about "just stick with using Panasonic battery for key fobs like VW Group do".

My daughter got the "Low battery" warning for her key fob for her 2019 SEAT Leon Cupra, she replaced that key fob battery with a new unused Panasonic CR 2025 - but made the fatal mistake of waiting until she quickly needed to use the car before checking that that key fob was back to working okay!

Anyway, she eventually swopped back to the previous Panasonic CR 2025 and got her car unlocked etc.

So, she wisely started using her partner's key fob until I next visited, I checked the previous battery and yes it's voltage was down to 2.99V so I swopped battery again using the one that she had previously fitted and had caused her issues, its voltage was 3.22V so should have been okay, but the "LED flash" when I pressed any of the buttons was very very "short", removed battery examined it and fitted it back in - same very very "short" flash - that daughter was away at work with her car, so I couldn't check that key with the car.

So, I messaged her and was told where to find more new CR 2025 Panasonic batteries, fitted another one, key seemed to work okay - ie the "LED flash" compared well with my 2015 VW Polo key fob - after she retuned from work, I checked the key fob - all good.

So, maybe currently, or when she bought these Panasonic "made in Indonesia", maybe the quality was not quite up to what I expected from Panasonic. Unfortunately, it seems that she bought 4 of these batteries at the same time, which when only planning to use them for 2 car key fobs, might not have been a smart plan.

Anyway, as it looks like she used the first of this batch of 4 Panasonic batteries at some time after I had replaced the battery in the other fob with a Sony CR 2025 - probably due to "car is complaining about my key fob battery cry for help", I think that that other key fob battery needs checking and probably replacing, so I'll just chance it by using the last of that batch of 4 Panasonic "best by 2030" CR 2025!

Edit:- I'm suspecting that that faulty Panasonic CR 2025 has either a high internal resistance or faulty internal contact welding.
Retali
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Re: Replace Key Battery Message

Post by Retali »

ciclo wrote: Sun Dec 14, 2025 1:23 am I used to use genuine Panasonic batteries until I discovered Maxell.
The physical store didn't have Panasonic, so I was forced to buy another brand, a blister pack of Maxell, they are supreme!
Worked perfectly for the 6R and various remote control models, and also for the Golf 7.5, which is quite finicky about the remote battery.
Ciclo bro, i used another brand (GP) and again i got the same message, you are propably right and it is the ECU stack on the message...
but i will try to get a panasonic one aswell, lmao i have like 4-5 c2032 spare batteries...
RUM4MO wrote: Thu Dec 18, 2025 11:49 am Further to my comment about "just stick with using Panasonic battery for key fobs like VW Group do".

My daughter got the "Low battery" warning for her key fob for her 2019 SEAT Leon Cupra, she replaced that key fob battery with a new unused Panasonic CR 2025 - but made the fatal mistake of waiting until she quickly needed to use the car before checking that that key fob was back to working okay!

Anyway, she eventually swopped back to the previous Panasonic CR 2025 and got her car unlocked etc.

So, she wisely started using her partner's key fob until I next visited, I checked the previous battery and yes it's voltage was down to 2.99V so I swopped battery again using the one that she had previously fitted and had caused her issues, its voltage was 3.22V so should have been okay, but the "LED flash" when I pressed any of the buttons was very very "short", removed battery examined it and fitted it back in - same very very "short" flash - that daughter was away at work with her car, so I couldn't check that key with the car.

So, I messaged her and was told where to find more new CR 2025 Panasonic batteries, fitted another one, key seemed to work okay - ie the "LED flash" compared well with my 2015 VW Polo key fob - after she retuned from work, I checked the key fob - all good.

So, maybe currently, or when she bought these Panasonic "made in Indonesia", maybe the quality was not quite up to what I expected from Panasonic. Unfortunately, it seems that she bought 4 of these batteries at the same time, which when only planning to use them for 2 car key fobs, might not have been a smart plan.

Anyway, as it looks like she used the first of this batch of 4 Panasonic batteries at some time after I had replaced the battery in the other fob with a Sony CR 2025 - probably due to "car is complaining about my key fob battery cry for help", I think that that other key fob battery needs checking and probably replacing, so I'll just chance it by using the last of that batch of 4 Panasonic "best by 2030" CR 2025!

Edit:- I'm suspecting that that faulty Panasonic CR 2025 has either a high internal resistance or faulty internal contact welding.
RUM4MO i will def try to get a panasonic one, but the way i see it, these type of batteries are not so commonly used so they stay on stock for a long time, so its also possible even for a panasonic battery to lose its power (i guess >)
I have used Duracell, Renata and GP so far, i will try to find a panasonic one too and let you know.
scott18T wrote: Wed Dec 17, 2025 8:46 pm I had the same issue after replacing the key fob batteries, the way I managed to clear the message,
was to disconnect the main battery for a couple of minutes.
I will try to find last time a panasonic alternative and if this does not work, i will just disconnect the earth terminal for a couple of minutes as you suggest ! Thank you
RUM4MO
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Re: Replace Key Battery Message

Post by RUM4MO »

Retali maybe after removing the earth lead, switch on the ignition and maybe even the headlights in an attempt to drain down/out any/all stored charge in the controllers that might be keeping them "alive" for this short period of "battery disconnection", as staying "alive" could leave them holding onto this, what is now a stored error state.

Just a random thought that might you getting the best possible chance of sorting this out quickly.
Retali
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Re: Replace Key Battery Message

Post by Retali »

RUM4MO wrote: Fri Dec 19, 2025 9:40 am Retali maybe after removing the earth lead, switch on the ignition and maybe even the headlights in an attempt to drain down/out any/all stored charge in the controllers that might be keeping them "alive" for this short period of "battery disconnection", as staying "alive" could leave them holding onto this, what is now a stored error state.

Just a random thought that might you getting the best possible chance of sorting this out quickly.
FIXED***** I removed the earth lead (did not open lights etc) , because i wanted to replace the botchered pin connectors of my map sensor plug (i also placed some seal connectors). And after 30 minutes of work when i placed the key to switch on the engine the message was gone.

Thanx EVERYONE for your time and help ! I did not buy the panasonic ones (for the record).

In any case it was the battery lollol.
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