Evening all,

My Audi A5 (35TDI) just passed its MOT with two advisories - one tyre related and one "battery suspect low".

The first is easy to rectify but on searching for a replacement battery I've seen a few mentions of having to recode the car to the new battery e.g. "otherwise the alternator will treat it as the old battery"?  Previous cars have simply been take old battery out, put new one in. Does the A5 really have to be coded? Is this another trip to the main dealer? 

Thanks for any assistance. 

In a word, yes. The battery does indeed need to be coded to the car. See this for an explanation:

https://www.youtube.com/watch?v=IJAScg6JrYI

 

24 minutes ago, cliffcoggin said:

In a word, yes. The battery does indeed need to be coded to the car. See this for an explanation:

https://www.youtube.com/watch?v=IJAScg6JrYI

 

Many thanks for the quick response and YouTube clip.

Cheers

Hello Alan,

I would suggest you get the battery efficiency and alternator output checked before renewing the battery - Halfords stores should be able to do that for you. 
If it does need replacing, your wallet would appreciate you coming back to us before buying any battery - anywhere. 
Kind regards,

Gareth. 

Modern cars are very susceptible to energy fluctuation, so a battery on the way out will throw up all sorts of errors, never mind cold cranking amps to turn the engine over. Sometimes it’s not just starting the car, but the battery under load.

As mentioned, it does need coded. Get the best you can afford, likely to be AGM.

Any progress with this Alan? 

On 4/17/2025 at 9:24 AM, Magnet said:

Any progress with this Alan? 

Evening Gareth - none to date as I've been away on a few trips. Car is running normally but I will replace the battery before Autumn / Winter.

I did have a follow up question - is it likely a local independent VW/Audi/Skoda garage could replace/recode the battery, rather than going back to the dealership (Edinburgh Audi)? 

Thanks

Yes Alan.

On 4/22/2025 at 9:35 AM, Magnet said:

Yes Alan.

Many thanks again.