Dead battery - no warning
11-13-2018, 07:10 AM
#1
Dead battery - no warning
So, the OEM battery was on its last legs a few months back ( it would only charge up to 25% according to my charger ).
Replaced it with an Advanced Auto Parts equivalent. My wife has been complaining that the car sometimes takes a while to start. When I check the battery with the charger it's always low and it needs to be topped off with the charger. Today she called me saying the car is totally dead, no power at all. She had not driven it for the past 36 hours. There is no warning that the alternator may be having an issue. Shouldn't there be such a warning? I know my BMW gave me a red battery indicator when the alternator went.
Replaced it with an Advanced Auto Parts equivalent. My wife has been complaining that the car sometimes takes a while to start. When I check the battery with the charger it's always low and it needs to be topped off with the charger. Today she called me saying the car is totally dead, no power at all. She had not driven it for the past 36 hours. There is no warning that the alternator may be having an issue. Shouldn't there be such a warning? I know my BMW gave me a red battery indicator when the alternator went.
11-13-2018, 03:12 PM
#2
So, the OEM battery was on its last legs a few months back ( it would only charge up to 25% according to my charger ).
Replaced it with an Advanced Auto Parts equivalent. My wife has been complaining that the car sometimes takes a while to start. When I check the battery with the charger it's always low and it needs to be topped off with the charger. Today she called me saying the car is totally dead, no power at all. She had not driven it for the past 36 hours. There is no warning that the alternator may be having an issue. Shouldn't there be such a warning? I know my BMW gave me a red battery indicator when the alternator went.
Replaced it with an Advanced Auto Parts equivalent. My wife has been complaining that the car sometimes takes a while to start. When I check the battery with the charger it's always low and it needs to be topped off with the charger. Today she called me saying the car is totally dead, no power at all. She had not driven it for the past 36 hours. There is no warning that the alternator may be having an issue. Shouldn't there be such a warning? I know my BMW gave me a red battery indicator when the alternator went.
It happened to me a while ago and it turned out to be an interior light.
11-14-2018, 03:22 PM
#3
Thanks
So I plugged into my charger and it showed 0% charge and like 6 volts. I let it run for about 6 hours and it got to 100% ( this is at 20A charging).
In the morning I monitored the battery with charger plugged in but not charging and the car off. Within 20 minutes the charge was at 97% and voltage was fluctuating between 12.6 and 12.7.
Anyway, my wife drove the car today, plugged it into the charger in the evening and it was at 100%. So, whatever killed the battery in the past, did not do so today and the alternator is probably working otherwise car would not have stayed at 100%.
I think this is one of the kind of problems that make people want to sell their car.
11-14-2018, 03:23 PM
#4
11-15-2018, 02:18 PM
#5
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2 things I did when I had battery issue
Well for me with similar symptoms — it turned out that the entire spare tire well was completely full of water - so I pulled the drain plug. I too went and bought a new battery because mine was old... but it had problems the next day.
So then, without knowing anything technical I replaced the battery control unit module - it’s the black box next to the battery. I don’t have that VAGCOM, which means I didn’t do anything additional other than replace the battery and the module.
WELL, and since I had put the plug back in, like 6 months later I was driving in the rain it so happened and got a low battery message — pulled over and pulled the drain plug again — wasn’t so much water but there was some, not near that module though, then I left the plug out this time, and I went on my way and for whatever reason it charged and the problem went away that time.
So then, without knowing anything technical I replaced the battery control unit module - it’s the black box next to the battery. I don’t have that VAGCOM, which means I didn’t do anything additional other than replace the battery and the module.
WELL, and since I had put the plug back in, like 6 months later I was driving in the rain it so happened and got a low battery message — pulled over and pulled the drain plug again — wasn’t so much water but there was some, not near that module though, then I left the plug out this time, and I went on my way and for whatever reason it charged and the problem went away that time.
11-16-2018, 06:47 PM
#6
Thanks
Well for me with similar symptoms — it turned out that the entire spare tire well was completely full of water - so I pulled the drain plug. I too went and bought a new battery because mine was old... but it had problems the next day.
So then, without knowing anything technical I replaced the battery control unit module - it’s the black box next to the battery. I don’t have that VAGCOM, which means I didn’t do anything additional other than replace the battery and the module.
WELL, and since I had put the plug back in, like 6 months later I was driving in the rain it so happened and got a low battery message — pulled over and pulled the drain plug again — wasn’t so much water but there was some, not near that module though, then I left the plug out this time, and I went on my way and for whatever reason it charged and the problem went away that time.
So then, without knowing anything technical I replaced the battery control unit module - it’s the black box next to the battery. I don’t have that VAGCOM, which means I didn’t do anything additional other than replace the battery and the module.
WELL, and since I had put the plug back in, like 6 months later I was driving in the rain it so happened and got a low battery message — pulled over and pulled the drain plug again — wasn’t so much water but there was some, not near that module though, then I left the plug out this time, and I went on my way and for whatever reason it charged and the problem went away that time.
It's bizarre, battery gets charged to 100% with charger but after sitting for a while it goes down significantly where it needs a 2 hour charge to get topped off to 100% again.
11-18-2018, 07:10 AM
#7
Ran VCDS on it.
Lots of low voltage warning from most components stored.
The only suspicious one is
Address 61: Battery Regul.
Cannot be reached
Do our cars have this?
Thx
Lots of low voltage warning from most components stored.
The only suspicious one is
Address 61: Battery Regul.
Cannot be reached
Do our cars have this?
Thx
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11-18-2018, 09:47 AM
#8
AudiWorld Senior Member
11-18-2018, 11:18 AM
#9
Do you know if this regulator could be the cause of the battery drainage?
I see that it's attached from battery negative terminal to ground(chassis). Is it possible for it to influence the rate of alternator charging?
Also, how do I unplug the damn plug in the picture?
Last edited by Costasz; 11-18-2018 at 11:25 AM.
11-18-2018, 01:49 PM
#10
AudiWorld Senior Member
probably has something to do with alternator...not shure though.. contact looks like you press tab in middle? and flip clip..and then pull out.. (little hard to see in pic...but shouldn't be hard to figure out =) )
there are sw updates to that module! if you have an ooold one...i updated mine years ago.
cheers/H
there are sw updates to that module! if you have an ooold one...i updated mine years ago.
cheers/H