Weird battery issue

[Sonic]

My car eats batteries as well, 3 in 3 years.

I was getting significant drain and the car wouldn't start after being idle for more then a few days... after lots of faffing about disconnecting the permanent line to the Alpine Headunit did the trick.

Annoying because it means whenever i switch off the car it loses its settings, but it appeared to be drawing serious amounts of power on standby, and it seems to be a fairly common problem with them.

I also had a set of terminals installed into the boot, because being an ABY coupe it was a complete PITA every time i had to jump it.

[A80Avant]

the 13,47 volt are way tooo low.... 14,4 are the lowest volt you MUST have...the battery newer got fully charged; even you drowe to the moon...if you have the acidweight meshured, you will figur out this... 1,20-1,22 arent half charged battery; when you use the starter you WILL overload the battery; and it will destruct selves....( batery cant deliver the current, the sterter needs+ petrolpump and so on...)
'full battery charge are 1,275-1,280....(strong acid)...change the regukator to 14,7 or 15 volt verson; in the end of generator
if you have a 60AH battery with 1,20 acidweight.. its only 25-30AH...

I don't think anyone will have 14.4V measured at the battery of an avant. If I have that at the alternator I then think its a matter of losses on the cable from and to the battery.

[A80Avant]

Small update.

alternator measurement today was 13.35V. That is even lower than what I measured at the battery initially at 13.47!
However the volt indicator in the car is above 14V when the car Is idling.

So at least I can assume that the battery + cable is not a major loss of power.

The drain today was quadroupled checked at 0.03mA only thing I removed was an additional connection of the ecu. I don't think it made a difference as ecu is off when I do the measurements.

I have put back on on the batteries this time.reconditioned with a ctek charger. Lets see what that does...

[caterpillar]

I don't think anyone will have 14.4V measured at the battery of an avant. If I have that at the alternator I then think its a matter of losses on the cable from and to the battery.

I had the 14,7 volt at the battery terminals in MY car ( audi200 avant).. no prob... no battery boiling or what ever.. better light.... no prob to start in 30 degrees below...better heater unit.... meshured with my FLUKE....

[twoqu]

Well at least you have halved the current drain!
Still think there is an issue at the alternator. The output is regulated so you should be seing the rating of the voltage regulator of we suspect 14.1V. Not sure where the gauge gets its feed from but its the voltage at the battery that recharges the battery. It would appear that the values you have are not adequate to charge the battery adequately.
The low voltage means excessive charging time and the other issue that have been raised which may be contributing towards your problem.

[A80Avant]

It may be that the alternator is tired. At least I have also eliminated the possibility it my batteries being wrongly charged. I have used the ctek charger and one of them seems to be behaving now.

I will source an alternator to have in order to replace in due time.

Thanks

[caterpillar]

I will source an alternator to have in order to replace in due time.
@ the regulator in the back of the alternator are the question.... the figure stamped om 14,6 volt or 15 volt....!!!
if the alternator are in car you may meshure the AMP by the 13,47 volt = maybee 5 amp...even the alternator have 150 amp....and are brand new...

[twoqu]

Well the Ctek will, depending on the model, put in either 14.4 or 14.7V and up to as much as 15.8V in a reconditioning mode. So if the vehicle behaves as expected witha battery fully charged off the vehicle then we are back to our theory of poor on the vehicle charging.
You could try a replacement voltage regulator. Obviously if its an internal issue with say the slip rings or other components than it might not make much difference. If its the original alternator is hasn't done bad but it must be near the end of its working life. Source a good quality replacement and have another 10-15 years of service.

[twoqu]

There has been some previous discussion of possible sources of more modern alternator to use as replacements. Unfortunately no one has documented it so we can say for certain. In theory assuming it is not physically too large, doesen't move, has the right belt tension and is wired correctly, I would think any alternator would work within reason.
Whether its possible to make a hybrid using ABY casings/pulley but say 150A guts might be worth investigating. Or alternatively there may be good quality aftermarket replacements that fit with little adaptation. I think the new Audi price is rather expensive.
The reconditioning industry is a bit hit and miss, thats why I was stressing good quality. Sure they look pretty but its the quality of the components and testing thats the issue. For example I recently used a NOS aftermarket starter motor I have had for a while. Included in the documentation was a computer print out of its performance. Thats what I would want to see ideally. I seem to recall someone on here having a nice shiney reconned alternator for not a lot of money and it died within months.

[A80Avant]

I will source an alternator to have in order to replace in due time.
@ the regulator in the back of the alternator are the question.... the figure stamped om 14,6 volt or 15 volt....!!!
if the alternator are in car you may meshure the AMP by the 13,47 volt = maybee 5 amp...even the alternator have 150 amp....and are brand new...

Sorry mate but with your writting I'm having trouble to understand what you want to say.

The alternator was reconditioned 4,5 years ago when I was in Greece and had my electrician check and replace bits which I don't remember how they are called. But it was already at the time functioning ok and we did it as a precaution. I think from memory its a bosch unit with the 120A spec. Not easy to check with the reverse manifold in place.

Belt to the alternator is ok. Unfortunately I don't have any reference of what the voltage was when the unit was reconditioned to see if there is a significant drop or not.

My ctek does recondition at 15.8v and I checked one of the 2 vartas that I just had it charged and reconditioned and it reads 12.38v

This is why I asked for other people with avants to check their voltage at their batteries. I have been told by 2 different specialists that the readings I have show the car is ok and alternator is ok. I shouldn't have a dropped battery even if I left the car off for a month. So their explanation was that either the battery was poor to begin with or my charging was not good.

My experience in this area is small as you can see so I don't know what or who to believe so for now as I cannot replace the alternator on my own, I will see if the ctek did something better in recharging the battery and if it doesn't go flat that means that my alternator is also working. If it does then it could be that the alternator is the culprit.

[twoqu]

Anything less than 12.6V is not a fully charged battery. Basically every 0.2V drop from 12.6V is a 25% drop. So you have a battery of less than 75% capacity.
Ideally you could the battery condition checked with a load tester. Any larger concern who might want to sell you a battery might have one even Halfords. Charge it up and leave it till the next day. Pop in and get them to test. That way you will know whether the batery is dying or dead.
If you do not have over 14V out of the alternator you have an issue.

[A80Avant]

Anything less than 12.6V is not a fully charged battery. Basically every 0.2V drop from 12.6V is a 25% drop. So you have a battery of less than 75% capacity.
Ideally you could the battery condition checked with a load tester. Any larger concern who might want to sell you a battery might have even Halfords. Charge it up and leave it till the next day. Pop in and get them to test. That way you will know whether the batery is dying or dead.

Even a new unusued battery I bought was 12.45v. Should I put that on the charger then?

How can a battery charger say its fully charged when after charge is not reaching the 12.6V?

[twoqu]

Batteries are effectively 6X2.1V cells = 12.6V.
No guarantee that even a new batery is not defective. Batteries might have an internal fault or sulphate issues on the plates which the Ctek recondition is supposed to remedy.
Seriously these are basic automotive electrical fundementals that a little googling would verify. Our theory has always ben that the battery were being damaged through persistant undercharging which seems to be verified through your testing.
Incorrect voltage at alternator, not enough voltage to charge the battery, battery never fully charged, internal changes in battery, degraded battery.

[twoqu]

Yes! Charge the new one up before fitting on the vehicle and see what it measures. Might as well start with the correct voltage. If you do not attend to the root cause its going to die the same way in my opinion. Just a matter of time.

[A80Avant]

How many people do you know that go to the shop to buy a battery with a multimeter at hand? I know that with googling you can find almost everything, but unless you have ever had a problem in the past you just dont give a second thought about searching for it. Hence since i never had issues with batteries in the past, i did not know about these things either. Add to that the fact that specialists say different things than what i read on this thread, and this make me even more skeptical into what may be happening. So it will just have to be a chance of waiting and seeing.

I will put that new battery on ctek recond setting and charge to see if it will reach the additional voltage. Perhaps batteries get left out without any use and can lose power that way.

thanks for sharing the info though. I will be updating this thread once i have more to update on!