"replace key battery" warning even after replacing battery twice!

[aaronc7]

I kinda went thru similar BS on my Audi. Turned out the 10 pack of 2032s I got from Amazon... After less than a year buying it, most of them were bad after measuring checking with a volt meter.

Bought a 6 pack at Lowe's all good since.

 

[VWNa]

This super old threat but google brought me here with my troubles and as I found a fix lemme post it anyway, note this is not to avoid bad new batteries but just generic when replacing battery.

Copy&Paste from erwin

Removing and installing ignition key battery
Removing
− Remove emergency key.
− Insert a small screwdriver −2− into the emergency key slot −arrow a
− .
− Turn screwdriver −2− −arrow b− to open catch −3− .
− Use a small screwdriver −3− to lift battery −1− −arrow a− .
− Pull battery −1− out of battery compartment −2− −arrow b− .
Installing
Note
♦
Before installing battery, always press any key once.
♦
This resets the transmitter unit so that it can detect a new battery.
Ensure correct polarity and mounting position when installing battery.
The positive pole is marked.
1 / 2
− Insert battery −2− into battery compartment by pressing slightly
−arrow a− .
− Assemble cover of battery compartment −1− and transmitter unit −3−
−arrow b− .

 

[FPP]

My 2016 Gold R sometimes presents the "Replace Key Battery" message when the battery is still good. I just ignore it until it comes up consistently (it is usually intermittent). It has always except once started (sometimes even after the "No Key in Car" message). That time it started with the key against where the key hole would be if it had one.

 

[RichS]

I’ve had my 2014 R from new and never had this problem until last year. I only buy Duracell from trusted suppliers [Waitrose]. Last year after having service and MOT done when I picked up car they said they’d changed the key battery. I pointed out that I only put a new battery in 2 weeks earlier, but they said the change battery warning had come up. I was surprised but let it go, and the battery they put in lasted 10 months, so I thought maybe the one I’d put in was a rare faulty one. After putting a new battery in last week the warning came up today. I can’t believe it’s a faulty battery, so removed and wiped battery and carefully and gently lifted the 2 contacts which are under the battery to ensure a good contact. Refitted same battery and warning not coming up yet.
Car is keyless by the way.

 

[The Fed]

Personally, I never buy Duracell anymore, only Energizer. Try getting a refund or replacement for a bad battery from them.

 

[RichS]

I don’t think the battery my garage changed was faulty, nor the one I put in on Sunday.
They’re only 3v so it doesn’t take much to cause a bad connection. Since I wiped the battery and tweaked the contacts the warning hasn’t returned.

 

[johng.wissig]

I don’t think the battery my garage changed was faulty, nor the one I put in on Sunday.
They’re only 3v so it doesn’t take much to cause a bad connection. Since I wiped the battery and tweaked the contacts the warning hasn’t returned.

Do you park in a garage with the doors of the car unlocked? Apparently the key and the car attempt communication when in range and unlocked. My GTI is outside and locked, i change batteries about yearly. The wifes Jetta is garaged unlocked and i replace them 2 or 3 times a year. My daughter moved home and filled the garage with crap so now the Jetta is outside and locked and better life. Could be coincidence, I don't know.

 

[RichS]

Garaged but always locked. Like you I usually only need to change the battery once a year.

 

[The Fed]

I've had the same issue. One can last over a year, another only 6 months. I think a new battery is 3.3v, but you can ask Google. If it reads anywhere near 3v, it's bad.

 

[RichS]

The CR 2025 is 3V not 3.3V, this is marked on the cell. So 3V doesn’t make it bad, that’s the correct voltage when new.

 

[M3bs1]

I’ve seen this issue pop up on a number of car forums. Some (maybe all?) manufacturers are applying a bitter tasting coating to coin cells to keep kids from eating them. Sometimes it needs to be cleaned off if the contacts don’t scrape through to make a good connection.