Keyfob battery alert to change on dashboard. Halfords declined to do it saying it needs a garage with a diagnostic tool to do it or else the system could lock me out the car?

Just get a new 2025 battery and DIY. 2 minute job easily done. Did mine yesterday no problems.

Did my 2 yesterday, very easy 2 minute job. 

 

 

Just make sure you have the old battery out and new one back in within a few seconds, not sure what new vag keys are like but our old passat fob it needed to be within 20 or so seconds. 

3 minutes ago, caprixpack said:

Did my 2 yesterday, very easy 2 minute job. 

 

 

Just make sure you have the old battery out and new one back in within a few seconds, not sure what new vag keys are like but our old passat fob it needed to be within 20 or so seconds. 

Good point. Come to think of it I did have the new battery out of the packaging ready and the battery swop was done very quickly.

1 hour ago, benterrier said:

Just get a new 2025 battery and DIY. 2 minute job easily done. Did mine yesterday no problems.

Thanks for your help, Guys.

3 hours ago, Memo said:

Halfords declined to do it saying it needs a garage with a diagnostic tool to do it or else the system could lock me out the car?

 

And that, boys and girls, is why we don't listen to what people in Halfords say....

 

Apparently the batteries in these remotes don't last very long, maybe 2 to 3 years.  No big deal or expense, just worth having a few in the drawer.  

You can get the battery cheaper at Asda 

44 minutes ago, Alex-W said:

 

And that, boys and girls, is why we don't listen to what people in Halfords say....

 

Apparently the batteries in these remotes don't last very long, maybe 2 to 3 years.  No big deal or expense, just worth having a few in the drawer.  

 

Oh jeez....

 

Why single out Halfords when this forum is littered full of similar misleading adivce when folk have asked their dealers about a problem? Or is poor advice only peculiar to every branch of Halfords?

 

And when speaking of poor advice - where did this change battery within 20sec nonsense come from?  You'll read many  threads on here from people saying their keyfob isn't working, and the advice is 'have you tried changing your battery?". They change the battery and hey presto, the keyfob is working again. That's all done within 20secs is it?

 

For the uneducated like myself, perhaps people could share their knowledge of how the keyfob works? Question: A battery provides power. You remove the battery, even if it's for just half a second and that power is removed - so how does the keyfob retain it's coding when there no power? In other words how does half a second differ from 20sec differ from 20min differ from 20hr?

 

I certainly don't know the answer but I'm going to take an educated guess the circuit board in the keyfob contains some type of EPROM. If you don't know what that is, it's an Erasable Programmable Read Only Memory chip. In other words a code can be written to the chip and will stay there permanently. You could in fact remove the battery for 20yrs farless 20sec, and the code will be retained until it's physically overwritten ( or the chip fails ). But I'm just an armchair expert who regularly shops in Halfords - what do I know?

 

Edited 1 March, 20206 yr by Guest

Fair enough I think of halfords to decline as it would be slightly embarrassing if they caused a customer to be locked out their car on their forecourt. 

52 minutes ago, Scot5 said:

 

Oh jeez....

 

Why single out Halfords when this forum is littered full of similar misleading adivce when folk have asked their dealers about a problem? Or is poor advice only peculiar to every branch of Halfords?

 

And when speaking of poor advice - where did this change battery within 20sec nonsense come from?  You'll read many  threads on here from people saying their keyfob isn't working, and the advice is 'have you tried changing your battery?". They change the battery and hey presto, the keyfob is working again. That's all done within 20secs is it?

 

For the uneducated like myself, perhaps people could share their knowledge of how the keyfob works? Question: A battery provides power. You remove the battery, even if it's for just half a second and that power is removed - so how does the keyfob retain it's coding when there no power? In other words how does half a second differ from 20sec differ from 20min differ from 20hr?

 

I certainly don't know the answer but I'm going to take an educated guess the circuit board in the keyfob contains some type of EPROM. If you don't know what that is, it's an Erasable Programmable Read Only Memory chip. In other words a code can be written to the chip and will stay there permanently. You could in fact remove the battery for 20yrs farless 20sec, and the code will be retained until it's physically overwritten ( or the chip fails ). But I'm just an armchair expert who regularly shops in Halfords - what do I know?

 

No need to get childish, the fob can loose its synchronisation with the vehicle when the battery is changed hence the do it quickly. 

1 hour ago, Scot5 said:

 

Oh jeez....

 

Why single out Halfords when this forum is littered full of similar misleading adivce when folk have asked their dealers about a problem? Or is poor advice only peculiar to every branch of Halfords?

 

And when speaking of poor advice - where did this change battery within 20sec nonsense come from?  You'll read many  threads on here from people saying their keyfob isn't working, and the advice is 'have you tried changing your battery?". They change the battery and hey presto, the keyfob is working again. That's all done within 20secs is it?

 

For the uneducated like myself, perhaps people could share their knowledge of how the keyfob works? Question: A battery provides power. You remove the battery, even if it's for just half a second and that power is removed - so how does the keyfob retain it's coding when there no power? In other words how does half a second differ from 20sec differ from 20min differ from 20hr?

 

I certainly don't know the answer but I'm going to take an educated guess the circuit board in the keyfob contains some type of EPROM. If you don't know what that is, it's an Erasable Programmable Read Only Memory chip. In other words a code can be written to the chip and will stay there permanently. You could in fact remove the battery for 20yrs farless 20sec, and the code will be retained until it's physically overwritten ( or the chip fails ). But I'm just an armchair expert who regularly shops in Halfords - what do I know?

 

 

I am personally quite distrusting about many many car parts places or even garages when it comes to advice.

I have been told many things that are either works of fiction or products of ignorance and prefer to make my own judgement based on the facts that I can gather myself.

 

I wouldn't advise people to not shop at halfords, however I also would never trust what the staff there necessarily say as I don't exactly believe they are experts.  You may be lucky and get some who have some knowledge, however they're largely just retail staff rather than ex mechanics or the like that you may find behind a parts desk in a specific car parts outlet.

 

The guys in the bike section are likely a different story mind as they're actually dealing with bikes.

 

Basically, if somebody at halfords told me something that sounded feasible I'd google it rather than believe it on face value.

Much the same as I wouldn't believe most of what they tell you in Currys-PC World at face value when shopping for electronics.  

 

 

That said, I also don't believe the 20 second thing myself...  the original battery is dead, hence it needs changing.  Why would taking it out make a difference and start a 20 second timer?

 

2 hours ago, Scot5 said:

 

 Question: A battery provides power. You remove the battery, even if it's for just half a second and that power is removed - so how does the keyfob retain it's coding when there no power? In other words how does half a second differ from 20sec differ from 20min differ from 20hr?

 

 

A capacitor is the answer to your question, if you change batteries on a Sky remote control you have to do it within a similar timescale otherwise it loses the code that you had previously programmed into it to allow it to operate the volume and the on/off controls of your TV saving you using 2 remote controls.

 

It certainly was the case of older vehicle remote keyfobs, whether its still true of the OP's vehicle or its just recieved wisdom I dont know but the vehicle handbook will certainly confirm.

Taken from my octavia 5e manual. 

7 hours ago, benterrier said:

Just get a new 2025 battery and DIY. 2 minute job easily done. Did mine yesterday no problems.

Thanks for the info.

That's good to know. 

How about if the spare fob has been flat for some time though?

Tried changing the battery in that one and not working even though red light on fob indicates power....... assume not recognised by car?

Two of my keys have given me the flat battery message, which is kind of nuts for a one year old car! I stopped using the first one when it gave me that message and began using one of the other two keys. Obviously a very bad badge of cheap batteries last year, they've lasted for many years on previous cars without any effort.

On 01/03/2020 at 09:51, Alex-W said:

 

And that, boys and girls, is why we don't listen to what people in Halfords say....

 

Apparently the batteries in these remotes don't last very long, maybe 2 to 3 years.  No big deal or expense, just worth having a few in the drawer.  

Try 6 months.... I changed mine towards the end of last year, replaced with a new 2025... then had the change battery warning again yesterday, luckily I now have loads of spare batteries...

I noticed there are two versions for sale.

 

Alkaline and lithium.

 

I purchased an alkaline as it was what I could find before flying for business and didn’t want a problem when back.

 

That lasted approximately 6 months, but the lithium version that replaced it has probably been good for 2 years since.

 

Definitely with making sure the battery is the right chemistry.

 

Worth adding I had no idea when I purchased it, just when I saw the word alkaline on the dead cell. I had assumed wrongly that they bc were all lithium.

Edited 12 May, 20206 yr by cheezemonkhai

Have a look at page 8. "Change key battery". 😎

I find my 2025's only last 6 months or so with KESSY.  This was with Duracell batteries too.

 

I am trying to 2032 model in the fob now to see if it lasts any longer.  Its a tight fit but the lid will close.

Thats true, kessy is draining key fob faster, I am replacing every year with 2025

On 01/03/2020 at 07:14, caprixpack said:

Did my 2 yesterday, very easy 2 minute job. 

 

 

Just make sure you have the old battery out and new one back in within a few seconds, not sure what new vag keys are like but our old passat fob it needed to be within 20 or so seconds. 

5 secs from covber open to cover closed.    Job Done