Help with Battery or Charging System Problem
05-18-2019, 05:08 PM
#1
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Help with Battery or Charging System Problem
I have a 2018 Carrera with only 2100 miles which is kept on a Ctek 4.3 in snowflake mode to keep it fully charged. An issue has arisen that I'm trying to figure out.
Here's the scenario:
Battery (original Banner oem) resting voltage after being removed from the Ctek for 2 hours and car locked so the electrical isn't awake is 13.02V so the battery seems fine.
Start the engine, let it idle in the garage and sit in the car and monitor the running voltage on the MFD. Voltage in sport mode starts out at 14.7V and gradually drops to 13.8V - 13.7V over an hour plus period of time. Daytime running lights, air conditioning and stereo are all on. Seems all is well with the battery and charging system.
After about an hour at idle on average the charging voltage begins to fall below 13.7V bobbing around from 13.7V to 13.6V to 13.5V back to 13.7V to 13.6V to 13.5V to 13.4V back to 13.7V etc and after around 5 to 10 minutes the charging voltage drops to 13.2V and the following warnings appear on the MFD:
Low Battery Start The Engine And Run For Extended Period, Steering Support Limited Drive With Caution, Start/Stop Mode Deactivated plus the radiator fans come on high speed and stay on.
Once this occurs there is no recovery from the warnings by letting the engine continue at idle. Blipping the throttle will send the charging voltage to 13.8V and it will then settle back down to 13.2V. When the engine is shutdown and the ignition turned back on without restarting the car the voltage is 12.7V and over several minutes will drop to 12.6V to 12.5V which seems normal.
Restarting and idling the car the warnings clear, the charging pattern of 14.7V - 14.6V gradually dropping to 13.8V - 13.7V returns and all is well for x amount of time (can take up to 2 hours) before charging voltage drops into the 13.2V range and the same warnings reappear.
After going through as described above I can shut off the engine lock the car overnight, not hookup the Ctek and check the resting battery voltage the next day and it'll read around 13.02V.
The battery seems good and the terminal connections are tight.
Anyone hear of anything like this, what could be causing this behavior in an essentially new car?
Here's the scenario:
Battery (original Banner oem) resting voltage after being removed from the Ctek for 2 hours and car locked so the electrical isn't awake is 13.02V so the battery seems fine.
Start the engine, let it idle in the garage and sit in the car and monitor the running voltage on the MFD. Voltage in sport mode starts out at 14.7V and gradually drops to 13.8V - 13.7V over an hour plus period of time. Daytime running lights, air conditioning and stereo are all on. Seems all is well with the battery and charging system.
After about an hour at idle on average the charging voltage begins to fall below 13.7V bobbing around from 13.7V to 13.6V to 13.5V back to 13.7V to 13.6V to 13.5V to 13.4V back to 13.7V etc and after around 5 to 10 minutes the charging voltage drops to 13.2V and the following warnings appear on the MFD:
Low Battery Start The Engine And Run For Extended Period, Steering Support Limited Drive With Caution, Start/Stop Mode Deactivated plus the radiator fans come on high speed and stay on.
Once this occurs there is no recovery from the warnings by letting the engine continue at idle. Blipping the throttle will send the charging voltage to 13.8V and it will then settle back down to 13.2V. When the engine is shutdown and the ignition turned back on without restarting the car the voltage is 12.7V and over several minutes will drop to 12.6V to 12.5V which seems normal.
Restarting and idling the car the warnings clear, the charging pattern of 14.7V - 14.6V gradually dropping to 13.8V - 13.7V returns and all is well for x amount of time (can take up to 2 hours) before charging voltage drops into the 13.2V range and the same warnings reappear.
After going through as described above I can shut off the engine lock the car overnight, not hookup the Ctek and check the resting battery voltage the next day and it'll read around 13.02V.
The battery seems good and the terminal connections are tight.
Anyone hear of anything like this, what could be causing this behavior in an essentially new car?
05-19-2019, 07:14 AM
#2
I may be misunderstanding-but I don’t think the car is designed to be left idling for hours at a time without actually driving. I am sure if the car drove you would not see the error as the alternator would keep it charged up.
05-19-2019, 08:52 AM
#3
Nordschleife Master
My thoughts exactly. Who keep their car idling for an hour?
05-19-2019, 09:02 AM
#4
I have a 2018 Carrera with only 2100 miles which is kept on a Ctek 4.3 in snowflake mode to keep it fully charged. An issue has arisen that I'm trying to figure out.
Here's the scenario:
Battery (original Banner oem) resting voltage after being removed from the Ctek for 2 hours and car locked so the electrical isn't awake is 13.02V so the battery seems fine.
Start the engine, let it idle in the garage and sit in the car and monitor the running voltage on the MFD. Voltage in sport mode starts out at 14.7V and gradually drops to 13.8V - 13.7V over an hour plus period of time. Daytime running lights, air conditioning and stereo are all on. Seems all is well with the battery and charging system.
After about an hour at idle on average the charging voltage begins to fall below 13.7V bobbing around from 13.7V to 13.6V to 13.5V back to 13.7V to 13.6V to 13.5V to 13.4V back to 13.7V etc and after around 5 to 10 minutes the charging voltage drops to 13.2V and the following warnings appear on the MFD:
Low Battery Start The Engine And Run For Extended Period, Steering Support Limited Drive With Caution, Start/Stop Mode Deactivated plus the radiator fans come on high speed and stay on.
Once this occurs there is no recovery from the warnings by letting the engine continue at idle. Blipping the throttle will send the charging voltage to 13.8V and it will then settle back down to 13.2V. When the engine is shutdown and the ignition turned back on without restarting the car the voltage is 12.7V and over several minutes will drop to 12.6V to 12.5V which seems normal.
Restarting and idling the car the warnings clear, the charging pattern of 14.7V - 14.6V gradually dropping to 13.8V - 13.7V returns and all is well for x amount of time (can take up to 2 hours) before charging voltage drops into the 13.2V range and the same warnings reappear.
After going through as described above I can shut off the engine lock the car overnight, not hookup the Ctek and check the resting battery voltage the next day and it'll read around 13.02V.
The battery seems good and the terminal connections are tight.
Anyone hear of anything like this, what could be causing this behavior in an essentially new car?
Here's the scenario:
Battery (original Banner oem) resting voltage after being removed from the Ctek for 2 hours and car locked so the electrical isn't awake is 13.02V so the battery seems fine.
Start the engine, let it idle in the garage and sit in the car and monitor the running voltage on the MFD. Voltage in sport mode starts out at 14.7V and gradually drops to 13.8V - 13.7V over an hour plus period of time. Daytime running lights, air conditioning and stereo are all on. Seems all is well with the battery and charging system.
After about an hour at idle on average the charging voltage begins to fall below 13.7V bobbing around from 13.7V to 13.6V to 13.5V back to 13.7V to 13.6V to 13.5V to 13.4V back to 13.7V etc and after around 5 to 10 minutes the charging voltage drops to 13.2V and the following warnings appear on the MFD:
Low Battery Start The Engine And Run For Extended Period, Steering Support Limited Drive With Caution, Start/Stop Mode Deactivated plus the radiator fans come on high speed and stay on.
Once this occurs there is no recovery from the warnings by letting the engine continue at idle. Blipping the throttle will send the charging voltage to 13.8V and it will then settle back down to 13.2V. When the engine is shutdown and the ignition turned back on without restarting the car the voltage is 12.7V and over several minutes will drop to 12.6V to 12.5V which seems normal.
Restarting and idling the car the warnings clear, the charging pattern of 14.7V - 14.6V gradually dropping to 13.8V - 13.7V returns and all is well for x amount of time (can take up to 2 hours) before charging voltage drops into the 13.2V range and the same warnings reappear.
After going through as described above I can shut off the engine lock the car overnight, not hookup the Ctek and check the resting battery voltage the next day and it'll read around 13.02V.
The battery seems good and the terminal connections are tight.
Anyone hear of anything like this, what could be causing this behavior in an essentially new car?
05-19-2019, 01:58 PM
#5
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Sorry guys and thanks for responding. The warnings first started happening when driving the car which made me think the battery was going bad. It's happened a couple times and I'm trying to figure out what's going on without driving it for fear of getting stuck and needing to call roadside service. I've had the battery tested and it tested good. The warnings have occurred at idle in as little as 30 minutes.
05-19-2019, 02:28 PM
#6
Sorry guys and thanks for responding. The warnings first started happening when driving the car which made me think the battery was going bad. It's happened a couple times and I'm trying to figure out what's going on without driving it for fear of getting stuck and needing to call roadside service. I've had the battery tested and it tested good. The warnings have occurred at idle in as little as 30 minutes.
05-19-2019, 03:28 PM
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I have an appointment setup with the dealer for it's first oil change and to have the battery/electrical system checked. Trouble is the warnings probably won't occur while they're checking it out.
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05-19-2019, 03:52 PM
#8
06-14-2019, 04:44 PM
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Finally getting back with an update. I had to reschedule my appointment with the Porsche dealer to June 11th so I could leave the 911 and get a loaner.
So this appointment was also to take care of the first annual oil change and multi point inspection in addition to diagnosing the electrical problem.
Drum roll: The problem was found!
The service manager said that there were a bunch of errors codes generated which they didn't need and cleared because after they finished with the oil change and backed the car out of the shop all the warning messages including the fans coming on immediately happened. The tech just drove the car right back in and went to work and found that the battery ground strap was loose on the end that connects behind the battery to the firewall. Part number 9A791518110 ground strap was ordered to replace the original to make sure the problem was fixed (rather than cleaning and tightening the original one).
So cool that it happened right away at the shop as it was an intermittent problem rather than have it act normally. Such a relief that the issue was found and better still that it was of a simple mechanical nature rather than software or something else.
Got some other questions answered I wanted to know:
For the oem Banner battery Porsche recommends using snowflake 14.7V mode rather than normal 14.4V mode if using CTEK battery maintainers.
There's no software update available to make rev match work in normal mode like in Sport or Sport+ modes. I like rev match and would like to be able to turn it on with the softer suspension setting of normal mode during less aggressive driving.
Before leaving I went into the showroom to see if there was any 911's. There was 'only' a Miami Blue GT3. I just happened to hit it right when they were moving it outside. Firing that baby up in the showroom and driving it out was quite a thing to watch and listen to.
There was a Porsche Rucksack in the trunk when I had the car returned to me that the dealer wanted me to have for all my troubles, nice surprise. When I got home and had time to check out the bag it was filled with other Porsche goodies including a polo shirt, first aid kit, thermal coffee travel mug and a flash light. $385.00 worth of stuff, they really went above and beyond when they didn't need to.
That's it, back to driving and hopefully this info will be helpful if anyone has similar symptoms arise.
So this appointment was also to take care of the first annual oil change and multi point inspection in addition to diagnosing the electrical problem.
Drum roll: The problem was found!
The service manager said that there were a bunch of errors codes generated which they didn't need and cleared because after they finished with the oil change and backed the car out of the shop all the warning messages including the fans coming on immediately happened. The tech just drove the car right back in and went to work and found that the battery ground strap was loose on the end that connects behind the battery to the firewall. Part number 9A791518110 ground strap was ordered to replace the original to make sure the problem was fixed (rather than cleaning and tightening the original one).
So cool that it happened right away at the shop as it was an intermittent problem rather than have it act normally. Such a relief that the issue was found and better still that it was of a simple mechanical nature rather than software or something else.
Got some other questions answered I wanted to know:
For the oem Banner battery Porsche recommends using snowflake 14.7V mode rather than normal 14.4V mode if using CTEK battery maintainers.
There's no software update available to make rev match work in normal mode like in Sport or Sport+ modes. I like rev match and would like to be able to turn it on with the softer suspension setting of normal mode during less aggressive driving.
Before leaving I went into the showroom to see if there was any 911's. There was 'only' a Miami Blue GT3. I just happened to hit it right when they were moving it outside. Firing that baby up in the showroom and driving it out was quite a thing to watch and listen to.
There was a Porsche Rucksack in the trunk when I had the car returned to me that the dealer wanted me to have for all my troubles, nice surprise. When I got home and had time to check out the bag it was filled with other Porsche goodies including a polo shirt, first aid kit, thermal coffee travel mug and a flash light. $385.00 worth of stuff, they really went above and beyond when they didn't need to.
That's it, back to driving and hopefully this info will be helpful if anyone has similar symptoms arise.
06-14-2019, 05:18 PM
#11
Nordschleife Master
I love a happy ending!
The Porsche goodies for your troubles is icing on the cake.
Good stuff!
The Porsche goodies for your troubles is icing on the cake.
Good stuff!
07-11-2019, 05:47 PM
#12
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Thanks for reporting back on the fix!
07-11-2019, 06:13 PM
#13
Well this is mighty unhelpful now but maybe it'll help someone in the future, it is likely that the error was triggered by the fans (high electrical demand) coming on after the extended idling (recommend to really avoid idling car this much), this led to the seemingly random nature of the fault. A bad ground is always a pain to figure out, great that they fixed it on first try!
07-11-2019, 06:14 PM
#14
