trlyka

I had stopped for gas and turned off my car. While waiting, I notice the screen says 'Weak Battery' then something about 3 minutes until it shuts down.

I have 39k on the car. My Audi care just ran out (of course) and I haven't done my maintenance yet only because I am not paying $500+ to Audi, so I need to schedule with my mechanic.

Do I need to replace it or just run a diagnostic on it to see if there is another issue? Winter is here, so I don't want to get stuck with a dead battery, but I wouldn't think it would be due for replacement yet.

Thanks

uberwgn

Do you have the VCDS tool? Is this the original battery, Trlyka?

trlyka

I have a Vag-Com, but unfortunately the laptop I use for it won't hold a charge, so I need to see if I need a battery for it. Yes, it is the original battery.

snagitseven

If it's the original battery, 5 years is about right for its life. Audi Care wouldn't have covered a replacement battery in any case.

trlyka

Ok, fair enough. Just as I am saving some money for the holidays....ugh

Audi-S5

Hey there, just wanted to know if it was the battery in the end? Or if not, what else it could have been? I have just had my battery replaced as I also was experiencing random Battery Weak messages whilst driving. Audi said it was the battery as there was an aftermarket one in there, they changed it, after a week the messages started popping up again. Twice I had to pull over, turn off the car and then restart it. Back with Audi getting more checks. Getting very worried now that I have brought a Lemon and a half 😕

audi8k

Did they diagnose the battery and the charging system, or were just guessing? If the charging system does not operate correctly, of course the battery can not stay charged.

Audi-S5

Who knows, Audi say they spent 6 hours initially diagnosing that the battery was at fault. Took it back to the dealer for more checks, still couldn't tell me anything concrete, just second guessing thinking it's the alternator having problems charging the battery, want to charge nearly $4k AUD to replace it. It really is a weird one as I took the car for a 20km drive today, roof down and media system playing, no 'Battery Weak' messages whatsoever, just so random.

Audi-S5

So I am still getting battery weak messages and decided to go and buy a volt meter to do some fault finding of my own however on the way home the battery got to the point where it was so low that I started getting a gearbox malfunction message so I immediately pulled over and turned off the engine. When I tried to start the car again it was dead. Ended up Calling roadside assistance to get the battery jumped started so I could get home. He checked the alternator and it was showing 13.07v so it looked to be charging. I got the car home and again checked it myself, it was showing around 13.24v. So later in the day I decided to have another check to see if there was any drain. Initially the battery was showing 12.04v before starting the car. After starting it, I noticed it dropping gradually below 12v, it got to about 11.87v which to me indicates that the alternator was not working or not turning, however about 30 mins later I checked again and it was again working as the voltage had gone up to 13.24v. Literally just checked 30 mins later and it has dropped to 11.48v. Now I'm stuck between thinking it either being a faulty alternator (or a faulternator) or the pulley is loose/worn. Any thoughts or suggestions? Thanks all

jagtoes

1st battery should be charged with a good battery charger of 10 amps or more. When charged it should read 12.6 volts or better. When you start the car the alternator should read 13.5 - 14.5 volts. anything less is an alternator problem. The alternators function is to maintain correct battery voltage . Also after you charge the battery let it sit for an hour then read it again. It still should be 12.6 vo or better and if not the battery is bad.