I’ve got this currently with my id5. I love the car love love love everything about it but ever since I’ve had it it intermittently tells me the 12 volt battery isn’t charged enough. I’ve researched the forums and checked I’ve got the right optimised battery settings etc but had come to accept that ever more frequently the opening / recognition of the key and the remote access via the app wasn’t working. Until last week after a long journey the car wouldn’t charge overnight and I couldn’t access the car at all . Completely dead. The rac had to force an entry as none of the normal key fob tricks worked. The 12 v battery was completely dead and we hadn’t even been able to access the car to open the bonnet to give it a jump. It’s been with vw a week now ( mainly because the garage hasn’t got round to looking at it with Easter) until I complained. I told them over and over that it’s a 12 volt battery fault and it simply needs replacing. They said it wouldn’t be that ( what to I know disabled female driver huh?) . Guess what ? They rang me yesterday to tell me they’d discovered it was a 12 volt battery failure ( no sh*t) and they’re replacing it under warranty- I can have the car back on Monday.