I was getting message to replace key fob battery every time I got in the car. I had noticed it on the test drive and the salesman said that was normal on switch on. However I mentioned it to the fitter when he checked my memory seats and he told me the batteries only last 3 to 6 months cos they're communicating with the car all the time. I've replaced them and not getting the warning anymore.

You can tell when a car salesman is lying - their lips move. PS. the battery life can be extremely variable, depending on quality/make.

Edited 23 June, 20223 yr by Warrior193
added note.

THink you need to move away from that garage, both the salesman and the fitter are mental:- My key fob is still working afater seven years.

I got x3 sets of keys for my 2019 Superb Estate L&K when I bought it from new. All x3 sets ran out of battery at the same time ( give or take a week or so) after just over 3 years. I only ever used 1 set which I kept in a Faraday pouch when not in use. The second set lived in a Faraday pouch in a safe at home in a safe, the last set my son has in a draw at his home about 3 miles away (not in a Faraday pouch & never used in the car). I think certainly from my experience it hasn’t mattered where I kept them or how often (or not) I used them the batteries expired at virtually the same time. 

Had my Superb 12 months and two weeks and still using the original battery that came in the fob.

6 hours ago, Eccles said:

THink you need to move away from that garage, both the salesman and the fitter are mental:- My key fob is still working afater seven years.

7 year old car at least - so assuming not a keyless entry car where the key is always transmitting. 

Our 280 is a March 2016 car and the KESSY keys are still on their original batteries, so now 6y4m have passed....

Well, I've replaced all three now, 2 minute job, and under £2 for 4. No warnings now, so wait and see how long they last.

 

I replaced the batteries in both my KESSY fobs in May last year and had to replace them again this week so 14 months in all. Panasonic CR2032 batteries used on both occasions.

I used Energizer 2025, Theoretically you can use 2032, but they were too thick for my fobs. We'll see how long they last.

I looked in the manual and it didn't say what type of battery they take so I opened up the fob, saw a cr2032 and replaced it like for like. I'm intrigued now whether the cr2025 perform any better?

The last 2 numbers denote the thickness of the battery, and probably the thicker it is, the longer lasting or more powerfull. As you have KESSY you probably need more power than mine. I tried a 3032 but it was too thick to get in mine.

1 hour ago, Jonboy984 said:

I looked in the manual and it didn't say what type of battery they take so I opened up the fob, saw a cr2032 and replaced it like for like. I'm intrigued now whether the cr2025 perform any better?

A 2025 is thinner than a 2032, less battery capacity so won’t last as long 

2 hours ago, ApertureS said:

A 2025 is thinner than a 2032, less battery capacity so won’t last as long 

 

Makes sense, thanks 👍

Opened mine and it’s a CR2032. 

2025 is 20mm diameter and 2.5mm thick, a 2032 is 20mm diameter and as you might now guess is 3.2mm thick, in theory a 2032 will last longer as it 28% thicker and therefore should have more capacity from increased internal volume - I would bank on it though! A good brand from a good supplier might be a better bet, but me I just change them as needed with any old battery.