So I've recently been having issues with what I believe is the battery on my car, I've had the car for about 3 years now and it's been totally fine, no issues what so ever, woke up Sunday morning to go out as I had plans and the car wouldn't start like it usually would, it sounded like the battery was dead. I have a carista plugged into my car pretty much 24/7 so I loaded the app up to check the battery health, it was showing 9%, i got told i needed a new battery, So... I went to go get a new battery, checked it when I installed it into the car and it was at 84% I'm not sure if that's right or not as I'm not very mechanically minded, iys been in 2 days. I drive to and from work an hour in the morning and an hour at night to get home, after 2 days the battery is now showing at 70%, could there be something draining it, I unplugged my carista and my usb, the only think I have is an aftermarket reverse camera which is a bootlid camera but it's not wired up, could that be something to do with it or could my alternator be on the way out ? 

I wouldn't worry too much. The fabia has smart charging and doesn't charge the battery to 100%. Could be that.

But after 2 days its gone downtown to 70% on the battery? That's not right is it? Or am I being paranoid 😅 

Was it the right type of battery ( EFB ? )

Was it coded to the car?

Do you have stop / start on the car?

 

Thanks. AG Falco

I've got a yuasa agm start stop on there now. Not sure what you mean by coded to the car, I don't think so

5 minutes ago, AGFalco said:

Was it the right type of battery ( EFB ? )

Was it coded to the car?

Do you have stop / start on the car?

 

Thanks. AG Falco

 

If your car has automatic idle stop and the original battery was EFB (likely) your battery management needs to be adapted (coded) to the new battery.

When fitted with a smart alternator, the BMS will control the alternator to charge the battery to around 75% - the remaining capacity will be via energy recuperative charging. 

1 minute ago, BomerTimpson said:

I've got a yuasa agm start stop on there now. Not sure what you mean by coded to the car, I don't think so

Most Fabia III's have an EFB type battery fitted.

If you now have an AGM type battery it would have needed to be coded to the car when fitted.

 

Your Carista might be able to do it.

 

Different batteries need different charging algorithms applied by coding the battery to the car.

 

Thanks. AG Falco

 

 

How would I do this ? 

1 minute ago, AGFalco said:

Most Fabia III's have an EFB type battery fitted.

If you now have an AGM type battery it would have needed to be coded to the car when fitted.

 

Your Carista might be able to do it.

 

Different batteries need different charging algorithms applied by coding the battery to the car.

 

Thanks. AG Falco

 

 

 

1 minute ago, BomerTimpson said:

How would I do this ? 

Try here first.

 

https://carista.com/en/blog/battery-registration-made-easy-ff5wxcivsg

 

Thanks. AG Falco

31 minutes ago, AGFalco said:

Try here first.

 

https://carista.com/en/blog/battery-registration-made-easy-ff5wxcivsg

 

Thanks. AG Falco

Appreciate it

Example below is from an OBDEleven, the make of battery is unimportant, the Ah wants to be correct as does the type (VW call AGM "fleece" so check your Carista for this setting if not then AGM), serial number is unimportant, generally from factory it's (ten ones) 1111111111 you can just change the last digit to two (1111111112), this change is important to let the computer know it's a change of battery.

 

Do not drive around with the Carista plugged in all the time only plug it in when required if either the Carista or VW's computers or programs have a brain-fart the excrement might hit the fan, plus it's another unnecessary battery / alternator load.

Edited 30 October, 20241 yr by nta16
spelling

11 hours ago, AGFalco said:

Try here first.

 

https://carista.com/en/blog/battery-registration-made-easy-ff5wxcivsg

 

Thanks. AG Falco

Ive just coded the battery to the var and its changed from 70% and gone up to 100% so maybe the cars computer thought it still had the old battery in maybe ? 

11 hours ago, AGFalco said:

 

 

 

 

Well done on the 'coding' and sorting the issue.  Possibly if you had driven the car more the computer might have realised you have a better state of charge in the battery but as you have the facility to 'code' it you might as well do that at battery change or as  soon as possible after.

Well the battery has been changed and the coding is done so I'll see how that goes. Cheers for the help everyone 

11 hours ago, BomerTimpson said:

I've just coded the battery to the car and its changed from 70% and gone up to 100% so maybe the cars computer thought it still had the old battery in maybe ? 

Exactly.

 

But don't expect to see your battery at 100% all the time, which is by design.

 

Thanks. AG Falco

No of course, I'll see how it goes 

No of course, I'll see how it goes 

That's why I do very occasional recharges with an appropriate battery charger when required to 100% charge as my wife's car does regular very short journeys.