Key Battery

[Tried5UserNames]

Last week the car told me that the key battery needed replacing. Started using the second key instead. Car was in the next day at the dealers for the dreaded SOS pop-pop so I got them to change it as they had to have both sets. Lo & behold today the car's telling me that the one I'm using also needs a new battery. Sounds a bit suss to me. Anyway, question is: when I put the new CR2032 in do I need to anything else for the car to recognise the key or is it plug & play? Cheers.

[Edela]

It is plug & play.

[Tried5UserNames]

Just now, Edela said:

It is plug & play.

Many thanks, Edela, much appreciated.

[strudlovina]

After some research, the Panasonic CR2032 batteries have a slightly better capacity and might last longer. 

[Mark Hiscock]

13 hours ago, Tried5UserNames said:

Last week the car told me that the key battery needed replacing. Started using the second key instead. Car was in the next day at the dealers for the dreaded SOS pop-pop so I got them to change it as they had to have both sets. Lo & behold today the car's telling me that the one I'm using also needs a new battery. Sounds a bit suss to me. Anyway, question is: when I put the new CR2032 in do I need to anything else for the car to recognise the key or is it plug & play? Cheers.

No matter what brand of batteries I use, the car is continuously telling me "Please replace key battery". I've asked the dealer to investigate when the car is in at the end of the month as I also think it's a bit suspect.

[Tried5UserNames]

3 minutes ago, strudlovina said:

After some research, the Panasonic CR2032 batteries have a slightly better capacity and might last longer. 

Thanks strudlovina, fortunately that is the type I've ordered. Four of them as apparently they have to be replaced fairly regularly as they drain if they're within 10 feet of the car!

[Tried5UserNames]

2 minutes ago, Mark Hiscock said:

No matter what brand of batteries I use, the car is continuously telling me "Please replace key battery". I've asked the dealer to investigate when the car is in at the end of the month as I also think it's a bit suspect.

How irritating, Mark. One of many annoying aspects of the whole software shambles.

[inspectorman]

Three months after changing mine I got the warning. Annoying but changed it again. The error message persisted. Eventually I realised the spare key - which lives in an allegedly RF proof pouch a long way from the car - had somehow contacted the car to tell it it was sad. Changed that one and all was OK. Got 2+ years out of the first set.

 

The dealer might not have changed both.....

[Tried5UserNames]

3 hours ago, inspectorman said:

Three months after changing mine I got the warning. Annoying but changed it again. The error message persisted. Eventually I realised the spare key - which lives in an allegedly RF proof pouch a long way from the car - had somehow contacted the car to tell it it was sad. Changed that one and all was OK. Got 2+ years out of the first set.

 

The dealer might not have changed both.....

Thanks inspectorman, time for me to buy a lead-lined wallet!!

[Mark Hiscock]

On 12/02/2023 at 07:54, Tried5UserNames said:

How irritating, Mark. One of many annoying aspects of the whole software shambles.

Today the dealer replaced the batteries with Panasonic branded ones and the warning message at startup has gone.

 

No magic button presses or procedures, just swapped the batteries for Panasonic branded ones.

 

Annoying as I've tried every brand but this one!

 

 

 

 

[vincewebb]

My 2016 Octavia displayed the same warning to change the key battery, so went out and bought one, the last CR2025 in stock. When I put the new battery in the key, it worked the key's LED OK but it wouldn't lock or unlock the car. This started me on a 3 day mission, researching how to synchronise the car with the key. None of the many methods I tried helped.

 

The solution for me was to go out and buy more CR2025 batteries from a shop that had fresh ones in stock as opposed to the last one that could have been on the shelf for goodness knows how many years. Now both keys have new batteries, they work perfectly and there was no need to mess about trying to synchronise the car to the key.

 

 

[DaveFromSydney]

Mine started telling me about the key battery needing changing a few months ago, after 1.5 years of usage.

So I changed the battery but after a while the message came back.

So I changed it again. And it came back.

So I changed it yet again but this time I took notes:

The old battery tested at 2.97 volts - not very good.

The new battery is an Energizer 2032 manufactured in Jan 2022 with a 10 year shelf life.

It tested at 3.39 volts - good.

After only 3 days I got the warning again.

Now that new battery tests at 3.03 volts.

So I though maybe the fault is in the key and it is draining the battery very fast.

 

But the car came with 3 keys and I have never used the other 2.

So I tried one of the others.  It starts the car ok but I get the battery needs changing message.

So I tested its battery and it too is down to 2.97 volts.

Perhaps that is to be expected after almost 2 years of inactivity.

 

So I wonder how long we can ignore these warmings for? It seems to me the key is still good for months after the message first appears.

Meanwhile if changing the battery only gives me 3 days before the message that is going to means hundreds of dollars per year on batteries.

It is hard to believe that it is all down to the difference between Panasonic and Energizer. Both are good batteries that should give months of not years in this type of device.

 

I will bring it up at the next service in a couple of weeks.

 

Also, have you found difficulty putting the key back together so that the spring and button work to keep the removable key blade firmly inside the key body?

[DaveFromSydney]

As an experiment I replaced the 3 day old Energizer by a new Panasonic battery since it is claimed that only those work well with these keys.

The results were the same. Within a day or two I got the message to change the key battery.

 

Since I have never actually had a problem with the key not operating I suppose I shall just have to ignore this message.

Perhaps I will change the battery once per year pre-emptively, as I do with the smoke alarms in our house.

 

 

[DaveFromSydney]

I had another thought. The key I use daily sits in a tray in my study alongside the two spare keys.

There are two walls between the study and the garage but the distance is only 5 to 10 meters.

Although I never do this, any of the keys can lock or unlock the car from the study.

So perhaps the car is complaining, not about the key used to operate the car, but about one of the others that it can see?

 

I will try an experiment where I put the 2 spares (which are probably quite low, being 2 years old) at the other end of the house inside a metal box.

Then I will see if I continue to get the warnings as I use the key with the new battery.

 

Edited 22 May, 2023 by DaveFromSydney

[SteveTheElder]

@DaveFromSydney you don't, by any chance, have an Apple AirTag or Amazon Tile or similar on your keyring do you? I ask because I have a theory...

 

I started getting the 'change battery' alert soon after attaching an AirTag to my car key and placing another in my wallet which I carry in a trouser pocket and that happens to be near the centre console key holder when I'm driving. New batteries would result in the same alert within days if not immediately, even new Panasonics. Since removing the AirTags I get no alerts.

 

So, my theory is that the NFC signal from the AirTags was causing some form of interference with the car to key communication resulting in the change battery alert.

 

As yet I haven't put the AirTags back which I guess would be a logical step to validate the theory.

[DaveFromSydney]

No I do not have one of those. I have an Orbit tag on my house keys. They are on a separate keyring to the car keys (which are in my pocket)  but are usually only a foot or two away (in the bin in the driver's door).

But Orbits use Bluetooth. And I have had the same situation for the last two years but it is only recently that I started getting the Change Key Battery messages.

 

On checking the Airtags I find on an Apple site:

"Your AirTag sends out a secure Bluetooth signal that can be detected by nearby devices in the Find My network. These devices send the location of your AirTag to iCloud — then you can go to the Find My app and see it on a map. The whole process is anonymous and encrypted to protect your privacy. "

So it seems that both the Airtag and the Orbit use the same principles, even if it is not NFC.

It sees really unlikely that Bluetooth is the culprit since it is used in our smartphones and smart watches which is a normal use case for cars.

 

Anyway, if the steel box thing does not work I will try take off the Orbit from my house keys and see if that does the trick.

 

 

 

Edited 22 May, 2023 by DaveFromSydney

[DaveFromSydney]

I got the car back from the dealer today.

Their advice is that the warning is more based on time than the actual battery level.

They advise changing the battery in all keys once the message is seen (even if you do not ever use the spare keys).

And then they advise operating the car with each key so the car resets its status for each of the keys it knows about.

 

[Zedboy]

Quick tip for UK posters … Timpson’s replaced my first battery last week for £15 after 16 months use. I very rarely use the fob buttons so wonder if that extends life? They have an offer on atm which I took up… £20 and lifetime free replacements 

[CS363]

I'll second the fact that Panasonic seem to be the only batteries that last after having constant battery warnings in the past and using multiple brands such as Energiser, Duracell and cheap Chinese ones. Eventually I bought two boxes of them as my motorcycle uses the same battery for it's keyless system. Since then absolutely no issues.

FWIW the boxes state CR-2032PG/1B as the part number

[DaveFromSydney]

On 01/06/2023 at 19:12, DaveFromSydney said:

I got the car back from the dealer today.

Their advice is that the warning is more based on time than the actual battery level.

They advise changing the battery in all keys once the message is seen (even if you do not ever use the spare keys).

And then they advise operating the car with each key so the car resets its status for each of the keys it knows about.

 

I followed that advice and it seems to have cured the problem.

I have not seen any messages since and it has been a few days.

[GWoodhouse]

Temperatures have dropped and therefore my keyfob has stopped working. Exactly the same thing happened last winter.

 

What a fantastically engineered system 😒

[LuxoviaRS]

On 23/05/2023 at 07:46, DaveFromSydney said:

I had another thought. The key I use daily sits in a tray in my study alongside the two spare keys.

There are two walls between the study and the garage but the distance is only 5 to 10 meters.

Although I never do this, any of the keys can lock or unlock the car from the study.

So perhaps the car is complaining, not about the key used to operate t

I was thinking maybe this will help.  Buying 3 faraday pouches or 2 for the ones you don't use for the purpose of not only blocking the signal so that the 2 other fobs are not constantly sending out signals that may be picked up from the vehicle nearby as well to prevent thieves from stealing your fob signal and making their own

[SouthernComfort]

43 minutes ago, LuxoviaRS said:

I was thinking maybe this will help.  Buying 3 faraday pouches or 2 for the ones you don't use for the purpose of not only blocking the signal so that the 2 other fobs are not constantly sending out signals that may be picked up from the vehicle nearby as well to prevent thieves from stealing your fob signal and making their own

I bought those for my spares a few months ago, exactly like the ones in your pic. All I can say is, I haven't had any problems with the keys, so maybe they are doing the trick. I also rotate my keys every 3 months so they get even wear.

[DaveFromSydney]

On 09/06/2023 at 14:37, DaveFromSydney said:

I followed that advice and it seems to have cured the problem.

I have not seen any messages since and it has been a few days.

And seven months later, still no problems.

[Clodius]

For everyone who has issues with key battery drain I have noticed that if I hang my key on a hook the LED in it starts flickering. If I set it on the table it stops blinking. I'm just wondering if any of you hang your key fob?