Replace key battery message

[DonCat]

Having replaced the battery in my key fob I am still getting the message 'Please replace key battery' whenever I press the starter button. Does anyone know how to get rid of it?

 

DonCat

[john999boy]

This is not a flippant answer but you need another battery as your replacement one wasn't any good. Lots of threads regarding this on here.

[kenfowler3966]

I have replaced mine several times with different quality batteries and still get this message. I carry a spare battery with me in case it fails completely now, but the car still always locks, unlocks and starts. 
I suspect different makes of batteries have slightly different fully charged voltages, and hence slightly different transmission power?

[CJJE]

I agree. I changed my batteries for Duracells from Boots (well within their sell-by dates but still got the message to change the battery. I then bought some Panasonic ones from Radiospares which had a higher voltage when tested and these were fine. 

 

The KESSY keys seem very sensitive to the battery type and of course transmit a radio signal all the time (or when they're moving for cars from MY20 on) saying "I'm here!!". As a result the batteries run down a lot faster than the non-KESSY keys and I plan to change them each year as a precaution.

 

Chris

[Routemaster1461]

There are threads on Skoda and other forums that recommend Panasonic, as other brands, including Dracell, don't seem to work. The problem is getting hold of Panasonic batteries. Not many places seem to stock them. Duracell and Energiser are no problem to obtain, and I suppose that is why many people try them and seem to have issues.

[smipx]

I am using Duracell in my 2 keyfobs and I put them in to both keys over a year ago. 

No issues here and never had an issue since they were replaced by the ones (presumably) put in by skoda when I got the car as a 1YO in March 2019.   It is the old Kessy without the "sleep mode" on the fob.  I planned to replace them every year whether they need it or not, just before the annual service, so this is a good reminder that mine have been in for 13 months now.

 

 

Edited 28 July, 2022 by smipx

[DonCat]

Thanks for this. I replaced my key batteries with Energisers from Halfords, and it seems as though I should try other makes of battery as a way of getting rid of the message.

[smipx]

So I just changed my 1YO Duracell and its still reading 3.02V on a multimeter but like a good person I am changing it. 

One thing I did notice is that the Duracells have an anti-child casing but also an anti-die if you swallow sticky label on the minus side.I removed this last year (obviously) but on the old battery I noticed a small sliver of tape that did not come off when I ripped off the sticker last time round.  It was totally invisible 1 year ago but age,air and dust has made it more noticable.  It goes virtually half way around the rim  of the minus side as you can see.   I wonder if some folk are leaving this bit of tape attached and, if you pop the battery in and this bit of tape happens to be where the contacts are - it may stop it working properly (or at all).   

 

One to watch out for 🙂

 

I have half peeled it off the old Duracell CR2025 battery so you can see what I mean:

[OldKaroq]

 

 

I am re-posting an old post of mine, which I think is interesting and could really help!!

 

 

I had a similar problem, replaced batterie s 11 months ago with Renata 2025, a brand I considered to be good. But like others with no warning as I was locked out of the car. I emailed Renata and got what I thought was a  good reply...

 

 

Regarding your finding:

On testing, the voltage was down sufficiently to stop the keyless entry from working. So the battery lasted just 11 months.

 

Regarding your comment:

2025 (180mAh) would appear to be greater than that of the Panasonic 2025 (165mAh)

The capacity alone does not say anything about the pulse capability of a battery.

 

The explanation is quite simple.

We have different batteries for different applications for CR batteries as well as for silver batteries.

 

For a car key as a good example, consider that the different temperatures (summer and winter) have a strong influence on the pulse capability.

Therefore datasheets are always using room temperature as base. (Independent of the manufacturer)

Using a battery that is not designed for higher pulses may mean that not all the capacity in the battery can be used.

 

For pulse application like your car key we recommend to use our CR20XXMFR (165mAh)

For application without pulse demand we (like a real time clock) we recommend to use our CR20XX.MFR (180mAh)

Attached I send you the two related datasheets.

 

I hope I have been able to give you an understandable explanation with these details.

 

Best regards from Switzerland

 

I won't bore you with the data sheets. I replaced the batteries with Energizer which are 165mAh as above. Less is more, it seems!!

 

 

[SurreyJohn]

I have used top quality Panasonic batteries and they do last, 9-18 months

 

Once made the mistake of using one I had spare in a unheard of brand, only got few weeks out of it.   
 

So even if it costs lot more use best batteries you can find, cheaper in long run

[Karock]

Attempting to start the car this morning and  had the message message "move key closer to the start switch"  ( or similar). Moved the key adjacent to the starter and the same message appeared. Car would not start..

As I keep spare fob batteries in the car I changed the battery, same message appeared and car would not start. Checked the main car battery and 11.9 volts so no problem there.

 

Decided to try and lock the car with the key fob, car locked instantly and then unlocked OK.

 

Then again attempted to start the car and all as normal and car started.  replaced the original battery and car starts as normal. 

 

 I noticed that I had not closed the tail gate completely and now always leave the car unlocked as it saves the main car battery discharging. Perhaps the partially closed tail gate had upset the software somehow and locking/unlocking had reset things?

 

[smipx]

18 minutes ago, Karock said:

"now always leave the car unlocked as it saves the main car battery discharging". 

 

Are you sure about that?

[Karock]

Yes, before when leaving the car locked and maybe parked up for 10-14 days the battery voltage as measured on the auxiliary socket  was always down to 11.4 volts.

Leaving the car unlocked the voltage now stays 11.9-12 volts.

[agedbriar]

If you let the battery rest below 12.4 V, sulfation occurs, which reduces the battery capacity.

 

To determine the true battery voltage at (closest to) rest, the voltmeter must be placed so, that it can be read without opening the door 20 min or more after closing/locking the car. Just opening the car door makes the voltage drop considerably.

 

 

Edited 31 July, 2022 by agedbriar

[agedbriar]

14 hours ago, Karock said:

Yes, before when leaving the car locked and maybe parked up for 10-14 days the battery voltage as measured on the auxiliary socket  was always down to 11.4 volts.

Leaving the car unlocked the voltage now stays 11.9-12 volts.

 

Here are the voltages that I just measured.

 

The car has been staying locked (Kessy) for the night. Through the closed window I can see the permanent voltmeter alternate between 12.5 and 12.6 V.

I unlock, open, and shut the door. The voltage drops to 12.2. I leave the car unlocked.

40 min later the voltage is stable again, alternating between 12.5 and 12.6 V.

I lock the car.

[smipx]

Hi,  That's what I would expect too agedbriar.  If my battery was constantly at 11.4V (or even 11.9V) then it suggests that there may be someting wrong with the battery or someting else is causing battery drain (like the Kessy being faulty or someting else).

I'm no expert mind 🙂

 

[agedbriar]

I'm afraid that the algorithm that charges the battery prevalently on decelerations and downhills, trying to as much as possible avoid charging on extra fuel consumption, will ruin many batteries by sulfation.

 

Living on a hill, I rarely return home with the battery fully topped up, as that would consume some fuel on the last leg of the trip.

 

 

Edited 1 August, 2022 by agedbriar

[Routemaster1461]

Just had the message on one key at 9 months, 8800 miles. Happened to have a spare Energiser from replacing the key in a fob from our other car. Seems to be OK. What I don't understand is why the keys above have 2025 batteries and mine seems to use a 2032.

[john999boy]

3 hours ago, Routemaster1461 said:

What I don't understand is why the keys above have 2025 batteries and mine seems to use a 2032.

I think 2025 is the correct one but the slightly thicker 2032 works fine too.

[agedbriar]

On my 2019 Kessy keyfob, the battery type (CR2025) is engraved on the inside of the battery cover.

 

 

[Routemaster1461]

1 hour ago, john999boy said:

I think 2025 is the correct one but the slightly thicker 2032 works fine too.

I put a 2032 in it because the original battery as supplied new was a Panasonic 2032.

[smipx]

Well I fitted a new 2032 into one fob and a 2025 into the spare (as I ran out of 2032's).  The 2025 did fit but I did have to fiddle a bit with a cocktail stick to press down the battery when I popped the lid back on. The 2032 does not seem to hold itself down in the hole like the 2025 does.  Got there eventually but if I was in a dark car with no power then I would not want to try and fit the 2032. If not careful you could easily mash the white gasket on the lid.

[DonCat]

Really glad to say that replacing the Energiser battery with a Panasonic has got rid of the message. Thanks to all for helpful messages.

[smipx]

I meant to say:   Well I fitted a new 2032 into one fob and a 2025 into the spare (as I ran out of 2032's).  The 2032 did fit but I did have to fiddle a bit with a cocktail stick to press down the battery when I popped the lid back on. The 2032 does not seem to hold itself down in the hole like the 2025 does.  Got there eventually but if I was in a dark car with no power then I would not want to try and fit the 2032. If not careful you could easily mash the white gasket on the lid.

Edited 2 August, 2022 by smipx

[NottsIan]

Having opened the key on my MY21 ( Sep 21 build ) , it has a CR2032 battery and the inside of the cover is marked as CR2032. Seems like the later keys were designed for 2032. Hopefully the increased capacity of the 2032 means they may last a bit longer ...