12 volt battery charge state detection recall coming out.

[DWG]

Received an email from NHTSA regarding 12 volt battery recall that affects 2021 - 2024 Bronco Sports built through March 13, 2024. Owner notification letters to be mailed after May 13, 2024.

Additional information here. RCLRPT-24V267-6161.PDF

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[johnardsg]

While we wait this is the potential consequence, no biggie :/

Consequence:
An undetected low battery charge can result in a loss of electrical accessories such as hazard lights, or cause a loss of drive power, increasing the risk of a crash.

 

[Mark S.]

You should consider rewording the title of this post. This recall is not a "battery recall." The cause of the problem (from the linked document):

The BCM and PCM calibrations are unable to detect a sudden change in the 12volt battery State of Charge (SOC) during a drive cycle.

The remedy:

Owners will be notified by mail and instructed to take their vehicle to a Ford or Lincoln dealer to have the BCM and PCM calibrations updated. There will be no charge for this service.

We've known for some time that these vehicles behave strangely when the battery voltage is low. As noted in the linked document, replacing the battery is the usual response. We now know the problem is not the battery, per se, it's that the car's software is not calibrated properly to detect and respond to a drop in battery voltage. This recall is to update software; it's not a battery recall.

 

[gatornek]

You should consider rewording the title of this post. This recall is not a "battery recall." The cause of the problem (from the linked document):



The remedy:



We've known for some time that these vehicles behave strangely when the battery voltage is low. As noted in the linked document, replacing the battery is the usual response. We now know the problem is the car's software is not calibrated properly to detect and respond to a drop in battery voltage. This recall is to update software; it's not a battery recall.

Its incumbent on the PCM to know precisely what the battery state is at, if its going to do things like auto stop/start. I don't turn this feature off, so it makes me think twice about how long is too long before changing the battery. I know two years is a good rule of thumb. Maybe I invest in one of those testers at Harbor Freight. Im loath to stop into my local auto parts store just to ask to borrow theirs. Miami 'auto parts stores' are not what they may be in more rural or even, suburban areas.

 

[coopny]

We've known for some time that these vehicles behave strangely when the battery voltage is low. As noted in the linked document, replacing the battery is the usual response. We now know the problem is the car's software is not calibrated properly to detect and respond to a drop in battery voltage. This recall is to update software; it's not a battery recall.

You're correct about the what the recall and what the remedy is, but part of the problem of why this is so serious is that the EFBs that Ford is shipping from the factory are crap. I'm also extremely skeptical about how the battery management system is choosing to charge these things.

The recall text states that "The body and power train control modules may fail to detect a change in the 12-volt battery state of charge.". If it's not detecting a change in the state of charge, it may not be running the alternator properly to charge the battery more fully. This could lead to the aberrant behavior on low charge (tons of warnings), the potential for the car to die while driving, and shortened battery life as the batteries are perpetually undercharged.

I think these reports of the batteries going bunk led many of us to suspect the battery management system. Based on what I've read online, the battery management system is a combination of systems and sensors and readings, but the actual reset command is sent to the Body Control Module (BCM) upon battery replacement to tell the BMS to retrain. For other behaviors like auto start/stop, it's important for the PCM to understand what's happening.

If so, it may be that the BCM/PCM is not only failing to flag this as a risk or disable behaviors/systems that are taxing on power when the battery state of charge is low (auto start/stop, maybe the infotainment), but also not charging the battery enough when the battery has a low SoC.

If so, it may not be that the Motorcraft EFBs shipped from the factory are complete crap failing in 12-24 months, but that the BMS has been perpetually mismanaging their charge (and the AGM batteries either don't experience this condition or just tolerate it better because AGMs charge much more rapidly and function with full power at much lower states of charge).

This is all conjecture of course, but I would be curious to see if this recall improves both battery state of charge and battery longevity.

 

[Bucko]

My head spins....

 

[Dude]

Fix applies to BCM and PCM, including these fixes

(1) inhibits auto start stop when the battery has a low SOC since owners reported their vehicle did not restart (this vindicates those that routinely (or permanently) disable their auto start stop),

(2) increase alternator output threshold to maintain vehicle operation.

 

[gatornek]

The recall text states that "The body and power train control modules may fail to detect a change in the 12-volt battery state of charge.". If it's not detecting a change in the state of charge, it may not be running the alternator properly to charge the battery more fully. This could lead to the aberrant behavior on low charge (tons of warnings), the potential for the car to die while driving, and shortened battery life as the batteries are perpetually undercharged.

Agreed.


I would say even more so than "die while driving" is the inability for the car to turn itself back on after an "autostop"

 

[RushMan]

You're correct about the what the recall and what the remedy is, but part of the problem of why this is so serious is that the EFBs that Ford is shipping from the factory are crap. I'm also extremely skeptical about how the battery management system is choosing to charge these things.

The recall text states that "The body and power train control modules may fail to detect a change in the 12-volt battery state of charge.". If it's not detecting a change in the state of charge, it may not be running the alternator properly to charge the battery more fully. This could lead to the aberrant behavior on low charge (tons of warnings), the potential for the car to die while driving, and shortened battery life as the batteries are perpetually undercharged.

I think these reports of the batteries going bunk led many of us to suspect the battery management system. Based on what I've read online, the battery management system is a combination of systems and sensors and readings, but the actual reset command is sent to the Body Control Module (BCM) upon battery replacement to tell the BMS to retrain. For other behaviors like auto start/stop, it's important for the PCM to understand what's happening.

If so, it may be that the BCM/PCM is not only failing to flag this as a risk or disable behaviors/systems that are taxing on power when the battery state of charge is low (auto start/stop, maybe the infotainment), but also not charging the battery enough when the battery has a low SoC.

If so, it may not be that the Motorcraft EFBs shipped from the factory are complete crap failing in 12-24 months, but that the BMS has been perpetually mismanaging their charge (and the AGM batteries either don't experience this condition or just tolerate it better because AGMs charge much more rapidly and function with full power at much lower states of charge).

This is all conjecture of course, but I would be curious to see if this recall improves both battery state of charge and battery longevity.

I have my doubts that this will be an effective fix, since I've seen my own car have a 100% SOC when I parked it, and then go down to 64% SOC just sitting in the garage for 5 days.
No, I believe that it is the constant battery draw from all the computerized electrification in the new cars, checking sensor, the anti-theft motion sensor, temperature sensors, etc.

 

[BSBB4Les]

I agree with all of you guys. Especially Bucko!

 

[Foghorn]

My guess is that Ford intentionally set charging system up so that alternator produces absolute minimum voltage, in an effort to maximize fuel economy. The low alternator output is insufficient to maintain proper battery voltage unless you drive a couple of hundred miles per day.
This assumes that an alternator is harder to turn as it increases output voltage.
I leave my auto start / stop on and when it stops working, I put a charger on the battery.
I must do this more in the winter, not so much now that warmer weather is here. This is the first vehicle I have ever owned that I had to do this, a combination of crap batteries and very high parasitic load.
If any of these assumptions are correct, watch for the reprogramming to increase our fuel consumption.

Fog

 

[Meanderthal]

I have my doubts that this will be an effective fix, since I've seen my own car have a 100% SOC when I parked it, and then go down to 64% SOC just sitting in the garage for 5 days.
No, I believe that it is the constant battery draw from all the computerized electrification in the new cars, checking sensor, the anti-theft motion sensor, temperature sensors, etc.

Not sure what the difference is, but my BS has been sitting for weeks at a time since I was laid off in December. I have gone weeks without leaving the house and I keep expecting to have an issue and need to jump start it. I have purchased a tender but I have not used it yet. If I had needed to jump start it, that would encourage me to install the tender. I have been very surprised, especially given the winter weather. It is kept in the garage which does shield it from the worst of the weather but it still gets cold out there. The one thing I can think of is that my key is stored on the opposite side of the house from the garage. I’m just wondering if that could be a contributing factor?

 

[RushMan]

Not sure what the difference is, but my BS has been sitting for weeks at a time since I was laid off in December. I have gone weeks without leaving the house and I keep expecting to have an issue and need to jump start it. I have purchased a tender but I have not used it yet. If I had needed to jump start it, that would encourage me to install the tender. I have been very surprised, especially given the winter weather. It is kept in the garage which does shield it from the worst of the weather but it still gets cold out there. The one thing I can think of is that my key is stored on the opposite side of the house from the garage. I’m just wondering if that could be a contributing factor?

My spare key is in the house, in an RFI envelope. My main key is not kept in an RFI envelope when I'm not driving. The car is garaged, in an attached but unheated garage, so I don't think weather is an issue. I never had a problem with my '17 Escape. I've taken the car to the dealer, who checked the battery and charging system and found no issues, no battery problem, and gave them green flags.

 

[Foghorn]

I suspect that Rushman and Meanderthal are both giving accurate reports. But there's the rub. Some owners seem to have batteries that exceed expectations and some got batteries that are woeful. That's what happens when a product is made to meet minimum spec's at the lowest possible cost. Some are great, others..meh.
Fog

 

[gatornek]

I have my doubts that this will be an effective fix, since I've seen my own car have a 100% SOC when I parked it, and then go down to 64% SOC just sitting in the garage for 5 days.
No, I believe that it is the constant battery draw from all the computerized electrification in the new cars, checking sensor, the anti-theft motion sensor, temperature sensors, etc.

Excuse my obtuseness, but what is "SOC"? And probably more importantly, WHERE exactly are you checking this?

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