Is it just low battery or is a replacement needed?

[T.Will]

Hi all, my car (66) didn't start yesterday after complaining 'low battery, will charge whilst you drive'.

I jumped it this morning with a power pack, disconnected dashcam, kept the mmi/screen off and drove for about 10/15 minutes.

When I parked and turned off the car and then switched it to accessories, as I had forgotten to close the window. It still gives me the low battery warning.

Here is a photo of the battery and the magic Eye thing is red. Do I just need to drive for a longer period of time or do I need to replace the battery?



Thanks in advanced

 

[northpole]

Drive it for about an hour or just let it idle for an hour... if the eye is still red after that you might want to check the voltage when the car runs.. should be max 14.5V ... than switch it off (remove key)and check the battery voltage ot should be over 12v... closer to 12.5 or higher... if it isn't than the battery is done for and needs replacing. But a trickle charger might bring it back to live... so I would try that first before buying a new battery.

 

[JohnM100]

As above. Also, had the car been unused for a while / doing only short journeys?

If the trickle charger says fully charged in a couple of hours then battery is dying. Depending on the rating, a trickle charger should probably need 18-24 hours to fully charge an otherwise fully working battery.

That said, if you can find someone local who has VCDS (see VCDS map) they can tell you how much usable capacity the car believes the battery really has at this stage if it’s life. At 7 years an EFB is likely on its way out and you’d probably just be postponing the inevitable when it refuses to start on a cold winter morning.

 

[T.Will]

A few short journeys last week <20 mins bar 2x 45 min drives, the dashcam (blackvue) has parking mode enabled but cuts off I believe at 11.8v I'm not entirely sure. Then its been sitting unused for the last 5 days. That could be the culprit.

 

[JohnM100]

A few short journeys last week

11.8V is a low cut-off. Combined with a 7 year old EFB, my money is on dying battery but the suggestions in the posts above remain valid. My old battery still started the car with 7Ah useable capacity: 10% of stated capacity.

If replacing, put an AGM in there. A bit more expensive but lasts longer and better able to handle both partial charge and high charge rate on the car overrun ie recuperation without shortening its life. You’d need to get the battery coded to the car (category fleece) but will last and save you a world of pain in winter.

 

[T.Will]

11.8V is a low cut-off. Combined with a 7 year old EFB, my money is on dying battery but the suggestions in the posts above remain valid. My old battery still started the car with 7Ah useable capacity: 10% of stated capacity.

If replacing, put an AGM in there. A bit more expensive but lasts longer and better able to handle both partial charge and high charge rate on the car overrun ie recuperation without shortening its life. You’d need to get the battery coded to the car (category fleece) but will last and save you a world of pain in winter.

Alright, thanks. I have her booked in at my local garage next week for another potential issue and they'll check the battery for me too.
In the mean time, I'll do the hour+ drive as suggested in the morning and see what happens.

Yes, maybe the cut-off was too low. There was a reason I put it so low but I probably should have double checked it was the correct thing to do with my particular battery and its age.

I'll set it to12.5v when I start using it again.

Thanks everyone for your help.

 

[NHN]

Grab a ctek & use that on a day off to charge, if it still has issues after that 8 stage process, then new one needed.

Get from Tayna, best battery company in the UK & good prices too with next day.

 

[T.Will]

Was out for about 2.5 hours but once I got back the eye was still red and the Low Battery came up once again.

@NHN I'll look into ctek thank you.

Failling that, in regards to a replacement battery my local garage says an Exide for £197 coded/fitted or £240 for Bosch.

Looking at Tayna after inputting my plate it asks if I have the suggested marked code (096/096EFB) which I cant see on this battery. How do I identify which battery to use or I can go for any start/stop EFB/AGM that it recommends based on my plate?

 

[JohnM100]

6R0 915 105 B is the part number which in Google comes back to an 096 industry wide designation for that size and capacity. I think all A3s of this generation use 096.

If replacing and funds allow, you’d be better off going for an AGM than EFB+ for reasons already stated.

I know Tayna have been mentioned but to complete the picture, the Bosch and Varta brands are made in the same production line, just different stickers on them. There is a small price difference but the Bosch used to have an extra year warranty over the Varta.

If going for the AGM, do get it coded in the car as the car charges EFB & AGM batteries differently.

 

[T.Will]

6R0 915 105 B is the part number which in Google comes back to an 096 industry wide designation for that size and capacity. I think all A3s of this generation use 096.

If replacing and funds allow, you’d be better off going for an AGM than EFB+ for reasons already stated.

I know Tayna have been mentioned but to complete the picture, the Bosch and Varta brands are made in the same production line, just different stickers on them. There is a small price difference but the Bosch used to have an extra year warranty over the Varta.

If going for the AGM, do get it coded in the car as the car charges EFB & AGM batteries differently.

Thanks, yes the Bosch does have an extra year. I'm going ahead and replacing with the Bosch S5 A08 AGM. Thanks again everyone.

 

[Harvey]

As previously mentioned you will need a new battery coding so the car knows it's been replaced and will charge accordingly.

An alternative to the CTEK charger is the cheap and yet surprisingly good Maypole MP7423 4A click for spec, which can be bought for around £25

 

[Fatbloke]

You can get a digital load tester cheaply to test it.

It will measure the actual cranking output of your battery and tell you if it needs replaced.

First thing would be to connect it to a battery charger and let it charge overnight.