Key fob battery replacement issue

[Brackett]

Got the "replace battery" sign on the dash, so got a new 2025 battery.

Replaced it, but no red flashing light, won't open the car.

Tried the "old" battery (which still had some life, I used the car today). Doesn't work.

Tried the battery from my other key fob, and that doesn't work either!! (if I put that battery back in Fob 2, Fob 2 works fine).

So in trying to replace the battery, the fob seems to have died!! Any ideas? Thanks.

 

[RADIOTWO]

Got the "replace battery" sign on the dash, so got a new 2025 battery.

Replaced it, but no red flashing light, won't open the car.

Tried the "old" battery (which still had some life, I used the car today). Doesn't work.

Tried the battery from my other key fob, and that doesn't work either!! (if I put that battery back in Fob 2, Fob 2 works fine).

So in trying to replace the battery, the fob seems to have died!! Any ideas? Thanks.

Depends what car you have ! if its the type with KISSY then they hammer the batterys also where did you get the battery from ?
We had simular problems and I went to the dealers and they replaced both batterys and after a couple of weeks they had failed so went back and they looked into it and as it was a maindealer they had sorced through Seat, and they found there had been a bad batch, so they got some more batterys and fitted them and no more problems.
Suggest you try a very good make and try some NEW ones

 

[Brackett]

2018 Leon, not KESSY.

I've now tried 3 batteries which I know work in other things (I've taken them out of other things which are working, including my other fob), and it's just dead.

 

[RADIOTWO]

2018 Leon, not KESSY.

I've now tried 3 batteries which I know work in other things (I've taken them out of other things which are working, including my other fob), and it's just dead.

Ok sounds like a duff fob, but have you put the battery in the right way!

 

[Brackett]

Ok sounds like a duff fob, but have you put the battery in the right way!

Yes, 100%!!

Bizarre. Working fine this morning, and even if i put the same battery back in now (or another one I know is OK) it doesn't work.

 

[Tivver500]

Had a similar issue with my Ford Kuga....
Eventually found that Duracell batteries worked but other brands didn't!! New batteries with exactly the same voltage so no idea why (and I'm an electronics engineer!!!)
I do have a stock of Duracell 2025 batteries all ready...... (car 6 months old now and so far fine......)

 

[Brackett]

Blimey, hope I don't have to try every brand of battery out there!!

The working battery from my other fob doesn't work in it though

 

[Seastormer]

I have changed my fob battery and used panasonic and had no problems, sounds like you have broke yours on opening it rather than a battery fault.

 

[emesee]

Hi Brackett
Did you resolve your issue?
Just had a similar problem. Changed fob battery following the message in the MFD. New Duracell exactly same as the one in the key. Opened car with it and started car but still had the same message. Turned off and locked car but when tried to re-open nowt happens. No red light etc.

so wondered how you sorted yours?
Thanks

 

[BoomerBoom]

I tried a couple of 2025 brands but neither worked, I got around the issue by using a 2032 battery instead - which has 50% more capacity.

It won't fit perfectly under the retaining clip, as it's 0.7mm thicker, but the key cover goes back on just fine and holds it all in place.

 

[emesee]

Well embarrassingly I took the battery out again, gave it a good old blow, back in and now works a treat. Although was odd how it worked once first time then stopped so will keep an eye on it. This time the message disappeared which gives me some confidence it’s now sorted.
Thanks for your reply!

 

[Brackett]

I see you're sorted now anyway, but yes I sorted mine in the end - meant to post, but forgot.

As above, nothing was working, including transferring the working battery from my other fob.

So I bought some brand new Panasonic CR2025 (the brand from my other fob), and that worked OK!

Just for kicks, I then again tried the working Panasonic CR2025 from my other fob - that still didn't work.

So my conclusion was that it needed to be a BRAND NEW Panasonic CR2025 and nothing else. But at some point that new battery I've now put in will be as "part-worn" as the one from my spare fob, so will it stop working in my usual fob then?

Seems pretty random... but at least we're both sorted now!