Intermittent Battery Drain

[GT Pony]

Well, when I was in for warranty work late May for idle issues I had them check the battery. It was all over the place on voltage 12.1-14.9. They said it was good?

Like I said ... the voltage will be "all over the place" because the "smart charging system" is trying to control the charging voltage based on inputs to the computer system. This charging system is not like the ones made 20 years ago where the charging voltage remains constant. I've seem mine anywhere from 12.7 to 14.3 volts. If you watch it on the dash while driving around you can see it fluctuate some.

Here's a descrition of the charging system in the S550 Mustang:

General Information
The PCM controls the voltage regulation setpoint and communicates this information to the generator internal
voltage regulator over a generator communication (GENCOM) communication circuit. The PCM receives
generator load and error conditions from the generator over the generator monitor (GENMON) circuit.

The PCM monitors the generator current using the generator current sensor attached to the generator B+ battery
cable. The information supplied to the PCM from the generator current sensor is used by the PCM to adjust the
engine idle stability and torque control.


Charging System
The PCM controlled Smart Charge charging system determines the optimal voltage setpoint for the charging
system and communicates this information to the voltage regulator. The Smart Charge charging system sets
Diagnostic Trouble Codes (DTCs) when a charging system fault is present. All of the Diagnostic Trouble Codes
(DTCs) can set continuous faults, but not all Diagnostic Trouble Codes (DTCs) set as on-demand faults.

This system uses 2 communication lines between the PCM and the generator/voltage regulator: A generator
communication (GENCOM) line communicates the desired setpoint from the PCM to the voltage regulator, and a
generator monitor (GENMON) line communicates the generator load and error conditions to the PCM. Both of
these use PWM. The PCM sends the GENCOM command only when it is necessary to adjust the voltage
setpoint. If the setpoint does not need to be changed, several seconds may elapse between PCM GENCOM
commands. This normal operation appears in the PID as occasional bursts of pulse-width commands. In addition
to these two circuits, a third pin on the voltage regulator, the "A" circuit pin, is dedicated to monitor, or sense, the battery voltage.

The PCM simultaneously controls and monitors the generator output. When the current consumption is high or
the battery is discharged, the PCM raises engine speed as needed to increase generator output. The generator
charges the battery and at the same time supplies power for all of the electrical loads. The battery is more
effectively charged with a higher voltage when the battery is cold and a lower voltage when the battery is warm.

The PCM turns off the generator during cranking to reduce the generator load and improve cranking speed.
Once the engine starts, the PCM slowly increases generator output to the desired voltage.

The PCM reports any charging system faults and sends a message through the High Speed Controller Area
Network (HS-CAN) to the BCM. The BCM controls the charging system warning indicator by sending a message
over the Medium Speed Controller Area Network (MS-CAN) to the IPC. The IPC then controls charging system
warning indication based on the message from the PCM through the BCM. The status of the PCM charging
system warning indicator and/or message is confirmed by viewing PCM PID generator fault indicator lamp
(GENFIL). Any charging system fault detected by the PCM results in 1 or more Diagnostic Trouble Codes
(DTCs) being set and the PID GENFIL having a status of On. If equipped with a charging system warning
indicator, the IPC turns the indicator on or off. If equipped with a message center, the IPC displays a CHECK
CHARGING SYSTEM message. In some instances, the CHECK CHARGING SYSTEM message may not
display if the ignition is on and the engine is off.

Under certain circumstances, the charging system may have a concern but still keeps the battery charged and
the vehicle running. GENCOM normally initiates charging but with a fault in this circuit, the generator can
self-excite and start charging on its own. The charging system warning indicator is illuminated and/or the CHECK
CHARGING SYSTEM message is displayed, and the generator operates in a default mode (approximately 13.5 volts).

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[Zinc03svt]

10-4, thanks for the info. I will run it back to normal (plugged in) for a while and see if starts fluctuating again. If not, may get the battery tested again.

 

[GT Pony]

Related info

Take a look at the Battery Management System thread. I actually unplugged mine because it was varying the voltage from 12.1-14 all the time. Now it just sits @ 14.1-14.4. Fyi.

I added some info in that BMS thread:
https://www.mustang6g.com/forums/threads/battery-management-system-reset.106897/page-5#post-2642693

 

[Cobraracer79]

I had a similar issue with my 2017 GT that I bought earlier this year with 100 miles. Obviously, it hadn't been driven or probably even started much for the first 2 years of its life. Once I got it and was driving it a couple times a week, I would occasionally come out to a dead battery. No rhyme or reason and it was all stock.

Brought it to the dealer and they couldn't find anything wrong with it. They replaced the battery on a whim and it has been fine since then (about a month). Not holding my breath, but it was definitely strange. I figure maybe I had a bad cell in the battery or some sulfation from not being driven enough.

I researched a lot and the closest thing I could find was people who had the enhanced security package seemed to be the ones who had similar issues. Do you have that package?

Yes, I have the enhanced security package and I did replace the battery with the same results.

 

[Cobraracer79]

I have been having intermittent dead battery issue. I have no after market accessories, there is about 6500 miles on it. Checked a lot of the threads but did not see anything kit this.

My car does sit for long periods and has gone in to deep sleep mode before, but I was still able to start it even after some time had past.
Recently it had sat a couple days since I had it out and was dead when I went to start it. Placed it on the charger in the morning. When I got home it was charged and the battery had 13.4 volts. I then drove 100 miles stopped for a few hours and then parked it about 8:00 PM. The next morning it was dead and I had a deep sleep activation notice about 4:15 AM. Out of town so I replaced the battery and went to my event the next morning it started, went to my event and then drove home. The next morning it was dead again and I had a deep sleep notice. Charged it up again and left for work, got home in the evening and the battery voltage was 13 volts, the next morning deep sleep alert and battery voltage was 7.2, when I got home from work it was down to 2 volts. Charged it up again and now 24 hours later it is 12.8 volts and no low battery alerts.
Testing was done with a voltmeter, not using the car gauge.

Something in the car seems to be cycling on and off, nothing plugged in to the 12 volt outlets. Even checked the trunk light to make sure it went off.

Taking it in to Ford, but still trying to figure out what it could be????? Looking for ideas.

Just an update:
Took it to Ford on Monday, got it back on Tuesday. They told me the battery and charging system was fine and there were updates needed but it was fine now. Not really an answer. Wednesday morning about 3:40 deep sleep mode notification. by 6:00 AM battery was dead. Charged it up last night, took it off charger this morning and it was at 12.9 volts. 6:00 PM when I got home the battery was at 1.9 volts. Back to Ford on Tuesday.
Also a lot of the Ford Pass functions stopped working while it was at Ford. Location, fuel, mileage, tire pressure would not update even fully charged Tuesday night (or any time since). It would start remotely when the battery was charged.
Love all the new features but sure miss the old reliable cars, no computers or BS to go wrong and none of the dam nannies that are on the new cars.

 

[Cobraracer79]

Back to Ford today, they found the issue this time. Wire on the bottom side of the fuse block (in engine compartment) had rubbed through and was grounding out intermediately.
Ford pass was not working so there is a computer they need to replace too.

Hopefully that is all for now.

 

[Bit_the_Bullitt]

I have a 2019 Bullitt and recently, due to quarantine I drive only about 1x/2x a week now. I have a dash cam with hw kit, both on accessory and on constant power (although I think all end up being switched off after certain time anyway).
I drove on Thu, then tried to start the car on Sunday and it was completely dead.

I thought that it was the dash cam that was draining the battery. Unplugged it for the last couple of days, got a trickle charger and a portable jump starter (since wife drives a hybrid and can't jump with her car).
Even with the dash unplugged and the car sitting for barely over a day without being driven, the trickle charger said it was charging up from 35%!! I don't know how in the world it's gone down that low.
When I bought my car, it had a check engine light due to battery (hasn't come back) and they put a new battery in. I wonder if these Ford Motocraft batteries are just junk?

Anyone experiencing similar issues?

 

[ugstang17]

I have a 2019 Bullitt and recently, due to quarantine I drive only about 1x/2x a week now. I have a dash cam with hw kit, both on accessory and on constant power (although I think all end up being switched off after certain time anyway).
I drove on Thu, then tried to start the car on Sunday and it was completely dead.

I thought that it was the dash cam that was draining the battery. Unplugged it for the last couple of days, got a trickle charger and a portable jump starter (since wife drives a hybrid and can't jump with her car).
Even with the dash unplugged and the car sitting for barely over a day without being driven, the trickle charger said it was charging up from 35%!! I don't know how in the world it's gone down that low.
When I bought my car, it had a check engine light due to battery (hasn't come back) and they put a new battery in. I wonder if these Ford Motocraft batteries are just junk?

Anyone experiencing similar issues?

The Motorcraft batteries are built by Johnson Controls along with four other battery brands...Interstate being one of those four. Do some research rather than blind speculation. The Motorcraft battery in my 2017 is original. It sits for 2+ months at a time in the dead of winter in an unheated garage without so much as opening a door and starts. Granted sluggish but it starts and then takes some time to build as would be expected.

Further, verify the power source you have the dash cam plugged into. Again speculation resolves nothing. From there you can then start troubleshooting the problem in a logical manner.

Could be a lot of things once you have verified that the dash cam isn't the leaching source.

 

[Bit_the_Bullitt]

The Motorcraft batteries are built by Johnson Controls along with four other battery brands...Interstate being one of those four. Do some research rather than blind speculation. The Motorcraft battery in my 2017 is original. It sits for 2+ months at a time in the dead of winter in an unheated garage without so much as opening a door and starts. Granted sluggish but it starts and then takes some time to build as would be expected.

Further, verify the power source you have the dash cam plugged into. Again speculation resolves nothing. From there you can then start troubleshooting the problem in a logical manner.

Could be a lot of things once you have verified that the dash cam isn't the leaching source.

I appreciate your input. However, please know I am not trying to attack Motorcraft brand, I simply raised a concern since I've had multiple issues with it, both the dealer did and so did I.
Furthermore, your anecdotal evidence of a good battery and my anecdotal evidence of a bad battery (possibly 2 bad batteries) does not make a good sample size to say they are good or bad product overall. I simply said they might be junk, i.e. the one that was in the car originally, triggered CEL and had to be changed and now the exchanged one is causing me issues as well.

I had the dash cam plugged into a constant power for low-power consumption mode with a voltage cutoff, and a regular accessory-powered fuse (so the dash cam recognizes when to turn on full power mode and high res recording), so it seems that it wasn't the issue.
Plus I stated that I am still having issues with it when the dash cam was not plugged in at all, so it isn't just speculation, rather it turns into method of elimination, eliminating the dash cam as the culprit (or at least the main one for now). I didn't just plug in two random new circuits thinking it's as simple as that. The issue is still there, so onward I go with testing.
I also trust the trickle charger, as it showed 95% charged after a jump and a long drive and when I test-started the car, it fired up faster, so I trust the trickle charger that it tells me it was at 35%. No wonder the car died after sitting for 4 days.

 

[Elp_jc]

The Motorcraft batteries are built by Johnson Controls.

As an FYI, it's been over a year since they sold it to a company that goes by 'Clarios'.

And by 'junk', we mean both that the battery is still a flooded cell (junk to me. Ha ha), AND that it's utterly undersized for a 12:1 CR 5.0L V8 IMO. So if it's sulfated even a little, it's no longer adequate. That's what happened to mine (replaced with a 96R AGM from Advanced Auto), and probably to 'bit-the-bullitt' too.

 

[ugstang17]

I appreciate your input. However, please know I am not trying to attack Motorcraft brand, I simply raised a concern since I've had multiple issues with it, both the dealer did and so did I.
Furthermore, your anecdotal evidence of a good battery and my anecdotal evidence of a bad battery (possibly 2 bad batteries) does not make a good sample size to say they are good or bad product overall. I simply said they might be junk, i.e. the one that was in the car originally, triggered CEL and had to be changed and now the exchanged one is causing me issues as well.

I had the dash cam plugged into a constant power for low-power consumption mode with a voltage cutoff, and a regular accessory-powered fuse (so the dash cam recognizes when to turn on full power mode and high res recording), so it seems that it wasn't the issue.
Plus I stated that I am still having issues with it when the dash cam was not plugged in at all, so it isn't just speculation, rather it turns into method of elimination, eliminating the dash cam as the culprit (or at least the main one for now). I didn't just plug in two random new circuits thinking it's as simple as that. The issue is still there, so onward I go with testing.
I also trust the trickle charger, as it showed 95% charged after a jump and a long drive and when I test-started the car, it fired up faster, so I trust the trickle charger that it tells me it was at 35%. No wonder the car died after sitting for 4 days.

Your written procedure is and was not clear. You stated that you disconnected the dashcam and put a trickle charger on the car. One day on a trickle charger reveals very little. A HD charger is needed in such cases. Had you clearly stated that you disconnected the dash cam AND then FULLY recharged the battery with an adequate device and were still having issues my response would have been different. The next step would have been to isolate any parasitic current drain through a step by step troubleshooting process. Easy to do with a current meter and some time. And it may have not been that at all. It could be a charging system issue not keeping up over time. Again something that can be isolated and verified. I troubleshoot for a living. There is a difference in troubleshooting and isolating a problem and simply making a speculation and throwing parts at it. I work with people who like to just throw parts at a problem because they would rather not take the time to learn the system. In the end it only costs more money because people would rather just have the fix over learning something in the process.

As for Motorcraft bashing I don't care. They make some good stuff and they have made some crappy stuff (I.E. the 2 piece plugs for the 4.6 3V a F150 5.4). I was simply trying to tell you the source from where they come. And for that matter, even good battery sources regardless of their design and builder have bad lot tuns from time to time.
That is why they put lot numbers and serial numbers on them. Contact Ford or Motorcraft and provide them with the lot number on the battery if you think it is suspect of such.

Good luck to you.

 

[ugstang17]

As an FYI, it's been over a year since they sold it to a company that goes by 'Clarios'.

And by 'junk', we mean both that the battery is still a flooded cell (junk to me. Ha ha), AND that it's utterly undersized for a 12:1 CR 5.0L V8 IMO. So if it's sulfated even a little, it's no longer adequate. That's what happened to mine (replaced with a 96R AGM from Advanced Auto), and probably to 'bit-the-bullitt' too.

12:1 is not all that great of a compression level given cars built in the 60's that ran much higher compression levels due to the higher octane fuel available then. They used lead acid wet batteries and had little issue with them. Given - today's cars use more electronics that need more current overall but the alternators of today are also much larger than in the days of yore as well to accommodate this. Sulfation can occur when the charging system is failing. Introducing a larger AH sized battery (not to be mistaken for larger cranking amp battery) without improving the charging system to accommodate can also cause this to occur... again due to what you mentioned which is caused by undercharging and never reaches full charge. Another thing that happens is that the acid falls out of solution to the bottom of the battery when not properly charged or when sitting on a shelf of uncharged for extended periods of time (stratification). If lead acid batteries are not cycled through in a reasonable amount of time they need to be put on charge so that the H2SO4 and H2O do not stratify. Stratification which is different from sulfation as big a culprit or premature failure than anything especially on cars that sit for long periods of time between drives. This is why trickle chargers and tenders were conceived. Boat owners who rely on marine batteries for their small electric trollers can relate directly to this problem. Further the acid concentration level (as a standard though may change on some batteries) should remain at hygrometer reading at or near 1280 when fully charged. A stratified battery cannot be properly recharged wit ha trickle charger or tender. That requires a constant current style charger capable of "stirring" the mixture during the charge process - which btw generates H2 and H2O evaporation (even in low maintenance batteries). So acid and water levels need to be maintained - though not as heavily as they were once in the olden days.

Nickelmetal Hydride, Nickle Cadmium, and even newer technology batteries such as the Lithium ion designs CAN develop memory if not properly discharged and fully recharged over time. This problem has been minimized over time but can still present problems. Further overcharging/fast charging can also become hazardous as we have learned with Li-ION batteries in laptops and cell phones in more recent years.

Any version of rechargeable drycell aside from early Ni-CAd (for no better term) is the better route to go no doubt. But at what cost difference? Given time either one can leave you stranded not just because of the battery design - but due to a failed or failing charging system.

Last - since green is such a concern to many these days - Lithium ION and its predecessors are not as easily recycled as lead acid batteries. Plus the cost to recycle is much more costly making the interest in doing so less attractive. Many just end up in a dump somewhere. https://phys.org/news/2019-12-lithium-recycled.html/

 

[Bit_the_Bullitt]

12:1 is not all that great of a compression level given cars built in the 60's that ran much higher compression levels due to the higher octane fuel available then. They used lead acid wet batteries and had little issue with them. Given - today's cars use more electronics that need more current overall but the alternators of today are also much larger than in the days of yore as well to accommodate this. Sulfation can occur when the charging system is failing. Introducing a larger AH sized battery (not to be mistaken for larger cranking amp battery) without improving the charging system to accommodate can also cause this to occur... again due to what you mentioned which is caused by undercharging and never reaches full charge. Another thing that happens is that the acid falls out of solution to the bottom of the battery when not properly charged or when sitting on a shelf of uncharged for extended periods of time (stratification). If lead acid batteries are not cycled through in a reasonable amount of time they need to be put on charge so that the H2SO4 and H2O do not stratify. Stratification which is different from sulfation as big a culprit or premature failure than anything especially on cars that sit for long periods of time between drives. This is why trickle chargers and tenders were conceived. Boat owners who rely on marine batteries for their small electric trollers can relate directly to this problem. Further the acid concentration level (as a standard though may change on some batteries) should remain at hygrometer reading at or near 1280 when fully charged. A stratified battery cannot be properly recharged wit ha trickle charger or tender. That requires a constant current style charger capable of "stirring" the mixture during the charge process - which btw generates H2 and H2O evaporation (even in low maintenance batteries). So acid and water levels need to be maintained - though not as heavily as they were once in the olden days.

Nickelmetal Hydride, Nickle Cadmium, and even newer technology batteries such as the Lithium ion designs CAN develop memory if not properly discharged and fully recharged over time. This problem has been minimized over time but can still present problems. Further overcharging/fast charging can also become hazardous as we have learned with Li-ION batteries in laptops and cell phones in more recent years.

Any version of rechargeable drycell aside from early Ni-CAd (for no better term) is the better route to go no doubt. But at what cost difference? Given time either one can leave you stranded not just because of the battery design - but due to a failed or failing charging system.

Last - since green is such a concern to many these days - Lithium ION and its predecessors are not as easily recycled as lead acid batteries. Plus the cost to recycle is much more costly making the interest in doing so less attractive. Many just end up in a dump somewhere. https://phys.org/news/2019-12-lithium-recycled.html/

Dang, this has turned from trying to troubleshoot my battery into a full blown battery discussion.
I appreciate all the inputs. I think what I'll need to do is monitor in the coming days and check the voltage on the battery each day and keep it trickle charging for now. I also am going to re-test the dash cam and set higher cutoff voltages (and also see if I can make it accessory-powered only) and report back.

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