How-To: remove and replace your 12v battery - recommended at 36 months

[Blue highway]

The dealer is supposed to reset the BMS when they replace the battery, but in a lot of cases they fail to do that. If you don’t have a way to check, I would recommend going through those steps to reset the BMS yourself to make sure it gets done.

When I changed the battery, I followed these steps from the thread above:

​

- turn MME 'off' once LVB has been charged to 100%​

- Press the START button without pressing the brake (ACCESSORY mode)​

- Flash the high beams with the stalk 5x​

- Press the brake pedal 3x​

- Battery icon on instrument cluster should flash 3x to indicate reset​

- Turn OFF the car​

- Turn OFF Fordpass and Bluetooth if you use PAAK so car-phone are not communicating​

- Park the vehicle undisturbed for 6+ hours to allow the BCM to verify the battery SoC and quiescent load​

The battery icon does not flash...

Are the steps above correct? any ideas?

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[dtbaker61]

When I changed the battery, I followed these steps from the thread above:

​

- turn MME 'off' once LVB has been charged to 100%​

- Press the START button without pressing the brake (ACCESSORY mode)​

- Flash the high beams with the stalk 5x​

- Press the brake pedal 3x​

- Battery icon on instrument cluster should flash 3x to indicate reset​

- Turn OFF the car​

- Turn OFF Fordpass and Bluetooth if you use PAAK so car-phone are not communicating​

- Park the vehicle undisturbed for 6+ hours to allow the BCM to verify the battery SoC and quiescent load​

The battery icon does not flash...

Are the steps above correct? any ideas?

per top post:


Reset new battery ONLY after charging it to 100%.
The easiest way to charge the new 12v to 100% is:

- turn MME ON
- Turn Vehicle>Settings>auto-off = DISabled
- turn Headlights, A/c, Heat, fan OFF
- .... and leave MME on overnight
- ODB2+Carscanner, or voltmeter, should verify that battery is 100% and
resting at 'float' voltage of 13.2v by morning

THEN, you can 'reset' the BCM to the new 100% capacity by:

- turn MME 'off' once LVB has been charged to 100%
- Press the START button without pressing the brake (ACCESSORY mode)
- Flash the high beams with the stalk 5x
- Press the brake pedal 3x
- Battery icon on instrument cluster should flash 3x to indicate reset
- Turn OFF the car
- Turn OFF Fordpass and Bluetooth if you use PAAK so car-phone are not communicating
- Park the vehicle undisturbed for 6+ hours to allow the BCM to verify the battery SoC and quiescent load

 

[Mach-Lee]

When I changed the battery, I followed these steps from the thread above:

​

- turn MME 'off' once LVB has been charged to 100%​

- Press the START button without pressing the brake (ACCESSORY mode)​

- Flash the high beams with the stalk 5x​

- Press the brake pedal 3x​

- Battery icon on instrument cluster should flash 3x to indicate reset​

- Turn OFF the car​

- Turn OFF Fordpass and Bluetooth if you use PAAK so car-phone are not communicating​

- Park the vehicle undisturbed for 6+ hours to allow the BCM to verify the battery SoC and quiescent load​

The battery icon does not flash...

Are the steps above correct? any ideas?

It should flash, you might be doing the high beam flashes or pedal pushes too fast or slow. Make sure they last at least half a second so they register.

 

[awiginton]

The dealer is supposed to reset the BMS when they replace the battery, but in a lot of cases they fail to do that. If you don’t have a way to check, I would recommend going through those steps to reset the BMS yourself to make sure it gets done.

I called the dealer they said my battery health shows at 93% and voltage at 13. The show the BCM update was done. Us thus the same as BSM?

 

[Mach-Lee]

I called the dealer they said my battery health shows at 93% and voltage at 13. The show the BCM update was done. Us thus the same as BSM?

No.

 

[kennelh]

Amazon has a battery tester with a 25%-50% discount today. I figure at $11 it's worth a try..

KONNWEI KW208 12V Car Battery Tester, 100-2000 CCA Load Tester Automotive

 

[CarsIMBwife]

.
.
the easiest way to charge the new 12v to 100% is:

- turn MME ON
- Turn Vehicle>Settings>auto-off = DISabled
- turn Headlights, A/c, Heat, fan OFF
- .... and leave MME on overnight
- ODB2+Carscanner, or voltmeter, should verify that battery is 100% and
resting at 'float' voltage of 13.2v by morning

THEN, you can 'reset' the BCM to the new 100% capacity by:

- turn MME 'off' once LVB has been charged to 100%
- Press the START button without pressing the brake (ACCESSORY mode)
- Flash the high beams with the stalk 5x
- Press the brake pedal 3x
- Battery icon on instrument cluster should flash 3x to indicate reset
- Turn OFF the car
- Turn OFF Fordpass and Bluetooth if you use PAAK so car-phone are not communicating
- Park the vehicle undisturbed for 6+ hours to allow the BCM to verify the battery SoC and quiescent load
…

I went to the dealer and had the 12V changed yesterday. I drove home and started the process above. The car has been on now for >20 hours, and I’m just at 95% using OBD reader. Will it charge if I plug the car into L2? My HVB is down to 35%. Not sure what I am doing wrong. No lights, no hvac, car is staying on, OBD unplugged. At 5:30 last night LVB was at 85%. Help?

 

[Snakebitten]

I went to the dealer and had the 12V changed yesterday. I drove home and started the process above. The car has been on now for >20 hours, and I’m just at 95% using OBD reader. Will it charge if I plug the car into L2? My HVB is down to 35%. Not sure what I am doing wrong. No lights, no hvac, car is staying on, OBD unplugged. At 5:30 last night LVB was at 85%. Help?

Ford's low voltage battery SOC algorithm is proprietary. What I mean is that their designated SOC isn't some standard measurement that the battery industry would reach consensus with.

Are you trying to reach 100% SOC from the OBD PID? I personally don't think it would have any value to it.

85-90% SOC using Ford's measuring is an AGM at a healthy SOC, day to day. (my opinion) And anything higher is a SOC that would likely be temporary with the way Ford tracks. If it was 95% SOC when you shut the car down, it might very well be 85% SOC when you start the car the next morning.

 

[CarsIMBwife]

Ford's low voltage battery SOC algorithm is proprietary. What I mean is that their designated SOC isn't some standard measurement that the battery industry would reach consensus with.

Are you trying to reach 100% SOC from the OBD PID? I personally don't think it would have any value to it.

85-90% SOC using Ford's measuring is an AGM at a healthy SOC, day to day. (my opinion) And anything higher is a SOC that would likely be temporary with the way Ford tracks. If it was 95% SOC when you shut the car down, it might very well be 85% SOC when you start the car the next morning.

I’m trying to get it to 100% in order to reset the BMS for a brand new 12volt.

 

[dtbaker61]

I’m trying to get it to 100% in order to reset the BMS for a brand new 12volt.

 

[dtbaker61]

The first charge to 100% may take quite a while. Yes you can plug in if you want to as long as the car stays on it will continue holding the voltage up for the low voltage battery. You may not be able to get it all the way up to 100%. But you can use the manual method to reset the BMS counter as outlined in the very top post. This resets the age counter and whatever capacity you get it up to it considers the new 100%. Anywhere above 95% is probably fine. What is the actual voltage?

 

[CarsIMBwife]

The first charge to 100% may take quite a while. Yes you can plug in if you want to as long as the car stays on it will continue holding the voltage up for the low voltage battery. You may not be able to get it all the way up to 100%. But you can use the manual method to reset the BMS counter as outlined in the very top post. This resets the age counter and whatever capacity you get it up to it considers the new 100%. Anywhere above 95% is probably fine. What is the actual voltage?

This is from 11:39 this morning:

 

[dtbaker61]

13.3 is full.... I.d do the manual 'age reset', and turn the vehicle off to rest for a couple hours

 

[zvez]

I went to the dealer and had the 12V changed yesterday. I drove home and started the process above. The car has been on now for >20 hours, and I’m just at 95% using OBD reader. Will it charge if I plug the car into L2? My HVB is down to 35%. Not sure what I am doing wrong. No lights, no hvac, car is staying on, OBD unplugged. At 5:30 last night LVB was at 85%. Help?

amazing to me the dealer didn't reset the BMS. How is this not the part of the dealer's responsibility? That's amazing.

 

[CarsIMBwife]

amazing to me the dealer didn't reset the BMS. How is this not the part of the dealer's responsibility? That's amazing.

I made an appointment a few days ahead, they could have at least put the battery on a tender first

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