2.0tsi Battery charging / elec issues, advice please.

[paddyoheater]

Hi there, sorry that my first real post is a cry-for-help!
I am hoping this is a simple battery coding issue, but need advice.

Car is 2006 A6 2.0 tsi automatic which I bought last year. Had a dead battery in the used car dealer lot, so he fitted a new battery (76Ah 650A) before I took delivery.
Battery lost charge after a few weeks, and dealer has been unable to sort the issue. He did make a decent effort but I don't think was equipped with VAG specific diagnostics.

My own probing with a multimeter shows that it the Battery (engine off) has 12.2v across the terminals, I also get 12.2v at the Charging point under the bonnet.
With the engine running I am seeing 14.2v off the alternator, and at the charging point, but only 12.3 /12.4 v at the Battery.

I am not getting any non-charging warning lights.

Other electrical issues have arisen, -maybe related to low voltage? -the Radio stopped working but does generate a random clicking sound , and the light cluster around the AC controls flicker in time, and the front cigarette lighter is dead (fuse is ok). On a traditional setup I would assume a bad connection / earth, and start poking about, but I am a bit scared of circuit boards and computer controlled gizmos!

I am guessing the first thing to get sorted is the charging, so is it a case that the car must be coded to a new battery, or will it learn over time that a new battery is present ?
Its a lovely old bus in all other regards, so hopefully your experience and advice will have it sorted.

Thanks for reading.

 

[KrisKrk]

Is the current battery also year old?
If new, like brand new, yes it need to be coded as ecu doesn't know what capacity battery has and how much charge it.
Also, yes it can learn itself overtime but till then battery can get damaged, as it will not charge to full.

You need to check for discharge and if the car draw any power while parked.
Another check should be your cranking voltage on alternator. This will show health of the alternator, as it could be on the way out. Although, it would show "no charge" message.

Another point is the actual size and type of the battery.
I recently installed 95Ah 850A AGM batter after originam AGM 92Ah 850A. Even without Start/Stop function, it was recommended to my car due to power need.
Check type and capacity your battery is.

To check overall battery health, go to KwickFit. They do free battery health check.
Think they do not charge if battery is ok
As KwickFit reputation is none, battery check cannot go wrong as it is meter clamped directly on the battery doing the work. LOL

Report your findings for further advice

Sent from my VOG-L29 using Tapatalk

 

[paddyoheater]

KrisKrk
thanks for your reply, I really appreciate it.

By some great luck, today I found the cause of my problems
The car was slow to crank and eventually started, but with a low-battery warning. I switched the engine off, and went to the boot to take a look, and found the
nut that connects the earth to the car body was super hot. To the point where a spot on it was glowing red-hot!
(this is not my picture but I have circled the offending nut)

I disconnected it (the bolt was not loose) and cleaned the nut and bolt with a wire brush and reconnected. Hey-Presto 13.75 charging volts, no more flickering lights or bad radio.
I had checked the contacts were all tight but some crud must have built up on the thread, enough to kill the power.
From now on I will check and clean connections, not just check for tightness.

I put the happy ending down to good karma from joining Audi-Sport.net. Happy Days!

 

[Wesleypef]

Из-За период пандемии право ряд поменялось, но около налоговой работы сейчас возникли новейшие способности с целью контролирования также рассмотрения.
бухгалтерские услуги цена

https://ooovirt.ru/blog/registratsiya-ooo-kazan/

регистрация ип в казани

ликвидация фирм
регистрация товарного знака

юристы по земельным вопросам
ooovirt.ru/blog/advokat-po-semeynym-delam/

 

[KrisKrk]

KrisKrk
thanks for your reply, I really appreciate it.

By some great luck, today I found the cause of my problems
The car was slow to crank and eventually started, but with a low-battery warning. I switched the engine off, and went to the boot to take a look, and found the
nut that connects the earth to the car body was super hot. To the point where a spot on it was glowing red-hot!
(this is not my picture but I have circled the offending nut)
View attachment 238246
I disconnected it (the bolt was not loose) and cleaned the nut and bolt with a wire brush and reconnected. Hey-Presto 13.75 charging volts, no more flickering lights or bad radio.
I had checked the contacts were all tight but some crud must have built up on the thread, enough to kill the power.
From now on I will check and clean connections, not just check for tightness.

I put the happy ending down to good karma from joining Audi-Sport.net. Happy Days!

Glad I could help anyhow.
I would recommend to plug in vcds, scan the car/save data, clear all errors and scan/save data again.
This way anything happen like that, you know what was the problem and what was done to it.

Good luck

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