Audi a4 b9 key fob not working after battery change

Blues14

hi can anyone help so I was getting a warning up on dash saying battery in key fob was running low so I got a new one but doesn’t seem to work is there a trick to get it to work.as soon as I put the old battery back in it work’s straight away I know I can unlock with key but I iv locked it with key fob if i unlock it with key the alarm goes off and I know there’s a place to place the key fob if the battery dead to start the car.would love to get the key fob working I hardly have to go to Audi

con747

https://www.boards.ie/discussion/2058369706/audi-a4-b9-key-fob-not-working-after-battery-change

Check the new battery isn't dead, I'm fed up buying batteries only to find they are dead. I bring a small battery tester now when buying any and test them in the shop in front of the cashier.

Blues14

but a different battery in still no good

con747

https://www.boards.ie/discussion/comment/122634772#Comment_122634772

Have you tested if the "new" battery isn't dead? A lot of those batteries are years old before they get sold and are either half dead or dead.

Blues14

no haven’t tested them but in different packs I’d have to be very unlucky to get 2 dead one surely

con747

https://www.boards.ie/discussion/comment/122634797#Comment_122634797

I tried 3 different "new" batteries from different shops last week, all were dead. They were cheap branded ones though. It's worth checking them as an easy way to know before going for the next options others can advise hopefully if it's a known issue.

Blues14

cheers knowing my luck I’ll have to go to audi and get reprogrammed

halkar

Did you put the battery correctly to the key. It's easy to make mistakes with negative and positive sides.

Blues14

yeah put in both sides no good

Atlantic Dawn

I had 3 differently sourced 6 packs of Duracell batteries with expiry dates after 2030 and not a single one worked in the car remote when I changed after a low battery warning. Went to the chemist and got one it worked first go, was even same brand. I'm not sure if they store bad or what, I had mine at room temperature and out of sunlight so should have been grand.

mickdw

If it works with old battery. You remove the battery and it works again with old battery, it cannot need any form of coding.

I think they are 2032 battery. Get a branded battery and ensure its in the right way up.

Blues14

you guys are right I put the battery that’s in my wife’s key fob and it worked never had that problem with batteries before it’s obviously a common thing thanks for help

con747

https://www.boards.ie/discussion/comment/122635005#Comment_122635005

Buy a small battery tester now! I got one like this

https://www.amazon.co.uk/Nartel%C2%AE-Analogue-Battery-Batteries-Requires/dp/B08T5QFWXQ

Blues14

cheers thanks for link