Key battery running out

[Serpher]

Is it normal for key battery in MK7.5 without key-less access to running out after about 4 months? I bought brand new battery and replaced it about 4 months ago and now car says to replace battery once again.
For a contrast: I haven't replaced battery in my other car for over 5 years (also no key-less access).

 

[Cuzoe]

Unless it happens again I would just chalk it up to a bad battery. I don't know where you get it from it may have been sitting there for a long time. Inventory turnover on them isn't likely to be very high.

Direct answer to your question is that four months is not typical.

 

[yeahforbes]

Yes, these batteries self-drain almost as quickly as they drain in a key fob. If you buy from Amazon, looks for RECENT comments with battery expiration dates, and choose one where nobody is complaining about short dates.

 

[EEeegolf]

My batteries lasted about 2 years. Today wife called and car didn't work. Realized spare key was also dead.
When I changed the batteries I modified the keys to accept 2032 instead of 2025. Just needs 0.7 mm cut off the plastic pressing down the battery

 

[yeahforbes]

If you have VCDS / OBDeleven and do a scan periodically, you will find a fault code when key fobs have low, not dead, batteries. Ridiculous that it's not exposed whatsoever on the dash without using a scan tool.

 

[Cuzoe]

If you have VCDS / OBDeleven and do a scan periodically, you will find a fault code when key fobs have low, not dead, batteries. Ridiculous that it's not exposed whatsoever on the dash without using a scan tool.

There is a key battery low warning that can show on the dash. I don't know the threshold for it to show. Conceivably a battery that goes from working to dead in a couple days may not trigger it.

That of course is not ideal. But it's also not true that low battery is not exposed whatsover on the dash. There are threads about the warning on this forum.

Stolen picture, EU Mk7 but same same...

 

[yeahforbes]

There is a key battery low warning that can show on the dash.

Oh wow! I wonder if I need to adjust something, because I've never seen that MFD notice.

 

[EEeegolf]

We didn’t have that sign before the car stopped working