Possible low battery issue but not sure???


Registered User
Jun 6, 2017
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My car is a 2007 2.0t quattro. Symptoms are as follows:

1 - first start on a morning is just lazy. Always starts first turn but just takes a bit longer and seems to struggle a bit. I can hear the fuel pump working when you open drivers door by the way.

2 - I've also noticed that my air con won't work if I put it on straight away first thing in the morning. Normally takes 10 mins of driving (so maybe charging up battery???) before it will work. I did have on my previous BMW that when the battery was getting low that it would limit the electrics you could use in the car....don't know if audi s are the same??

3 - I've invested in a multimeter and my battery at resting (Not used car for 24 hours) measured 12.34v. Now according to haynes it should be 12.6v and it said at 12.3v I'm around 50% full charge.

So I suppose my question is, is it battery change time with that reading??

Thanks guys

Gaz :icon thumright:


Audi A3 2010 Sportback 2.0 TDI 170 (CBBB engine)
Dec 5, 2014
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As you say, an "engine off" battery reading of 12.3 V is too low and is around 50% discharged. The ECU is most modern cars will typically "turn off" what it considers to be non-essential electrical items when it tries to ration voltage to "essential get home" electronics. Typically, things like ABS, central locking and ICE are affected.


A6 C6 4F 2010 LeMans Avant
Oct 11, 2016
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Check your alternator as I experience similar problems with my battery.
My 2010 A6 still has oem battery but it's very low on juice so it jas been tested in two different garages and result is same: "good, recharge".
However, if electrics put on ie. heating, lights, indicators, side mirrors heating, charging show just 13.33volt and at resting (engine off) 13volt.
This means, your battery isn't getting enough juice from alternator.

If you change your battery and have faulty alternator, your new battery will end up the same.

Sent from H P20 PRO


C'mon you's bhoy's in Green
VCDS Map User
Silver Supporter
Oct 14, 2009
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Get someone with Vcd's and plug it in and see what your battery is saying at idle then you will get a better idea. Check that boot light, glove box , interior lights and Radio go off once you pull key out so there isn't any charge getting drawn from it . You could do a parasitic draw test . YouTube