rather than get a new battery, if you're not using your car often (as most of us aren't at the moment), it may be worth getting a battery conditioner and keeping it ticking over with that. It's been used on my car a few times in the recent months and my bike the rest of the time.

Bit late to be updating this thread, but for the benefit of anyone reading:

 

• @tunedude's suggestion of keeping the car on a battery maintainer would have got me through the cold snap & lockdown, the OEM battery wasn't totally dead
• on a VAG forum (someone else's thread re a Golf), a poster advised against DIY, saying that disconnecting the battery without an auxiliary supply would cause loss of memory for various settings, notably that the steering angle sensor would need re-setting afterwards. I found this to be true, steering felt looser afterwards but re-adjusted itself over a week or two. I learned later that this can be re-set by the owner, e.g. this guide or this guide.

In the end I did code the car (but a good while after fitting the battery, and only out of curiosity).

 

If you're coding when fitting a Yuasa YBX9096 battery, I used OBDEleven to do it:

• Gateway -> Adaptations -> Battery Adaptation
• BEM code: YG0 (that's a zero. This code wasn't easily found on the web)
• Enter figures for Ah and Serial#
• Select 'Fleece' as battery type (for AGM).

 

On 23/01/2021 at 11:00, EVangelist said:

Thanks all for the replies, it's been a great intro to this forum

 

Based on @classic's input (that the car will figure out the battery's state of health and adjust itself), I'll go ahead and replace without coding, and post back if I notice anything negative.

 

The old battery wasn't so bad that the car was disabling start-stop or other functions, but cold weather, lockdown and hence very short journeys mean the battery was needing a charge before I could use the car if it's been sitting for more than 2-3 days. And a battery tester says it needs replacing, though I was hoping to put it off until next winter.

Did your battery eventually fail,? My agm battery is now 6 years old. I have a similar tester( Topdon) . I think they are a bit pessimistic on failing a battery. It’s been telling me to replace my battery for the last 2 years and now reads 26% SOH. It’s still started the car no problem recently at -7 degrees. Maybe it’s an AGM thing.

On 06/01/2023 at 22:59, Micky 32 said:

Did your battery eventually fail,? My agm battery is now 6 years old. I have a similar tester( Topdon) . I think they are a bit pessimistic on failing a battery. It’s been telling me to replace my battery for the last 2 years and now reads 26% SOH. It’s still started the car no problem recently at -7 degrees. Maybe it’s an AGM thing.

 

Hi @Micky 32, it hasn't failed, but it's not as strong as it should be! I swap the old Varta back in once/twice a year for a couple of weeks to re-condition & fully re-charge the newer Yuasa battery on a smart charger. The Varta is still able to start the car, but I only get start/stop after a long journey, and not if I'm running loads such as headlights,  AC or a 12V coolbox.

 

My battery tester stopped working (cable issue?), so I don't know what a test would report for the old battery now.