Planning for 12v battery replacement

[DaveQ]

Getting "Service 12v battery soon" message. How much should this cost at a dealership?

Sponsored

 

[HuntingPudel]

If your car is still under warranty and you do not have a service contract/extended warranty, they should pro-rate the battery based on its expected lifetime (not sure what that is for the MME 12V). I would expect something less than $250 for the actual battery and whatever your dealer charges for the labor to open the frunk, remove two panels, loosen 2 nuts, remove the cables, undo the battery retainer, remove the battery, then reverse that process and re-train the BMS (which is probably less time than it took to type this).

 

[srogers]

I had this problem several months ago, and this procedure provided by Mike G fixed the problem for me.

Reset your 12V battery learned values to ensure the battery is fully recharged while driving.

Here's how to do that:
Press the start button without stepping on the brake.
Flash the high beams with the stalk five times, and then step on the brake pedal three times, and after that, check the red battery icon on the instrument panel to see that it flashes three times. And then shut the ignition off. And then you can turn the car fully on and drive off. Your 12V battery should then fully recharge (if it wasn't doing that before).

 

[RickMachE]

If your car is still under warranty and you do not have a service contract/extended warranty, they should pro-rate the battery based on its expected lifetime (not sure what that is for the MME 12V). I would expect something less than $250 for the actual battery and whatever your dealer charges for the labor to open the frunk, remove two panels, loosen 2 nuts, remove the cables, undo the battery retainer, remove the battery, then reverse that process and re-train the BMS (which is probably less time than it took to type this).

Battery is covered for 3 years, 36,000 miles. No proration.

 

[Mach-Lee]

Getting "Service 12v battery soon" message. How much should this cost at a dealership?

Recommend you try a service charge on it first before replacing it. See details here:

Thread 'How to Recondition/Service Your 12V Battery'

If that doesn't work, then you can try to reset the BMS only after the battery is fully charged for 8+ hours.

 

[HuntingPudel]

Battery is covered for 3 years, 36,000 miles. No proration.

Good to know. Ford was trying to pro-rate my Fusion Energi's battery when the thing died with less than 6 months on the calendar after I bought it (12V battery had a year old date code). They told me the thing was only warranted 100% for the first year and pro-ration happened after the first year. Happy Ford changed that.

 

[Chuck]

I had this problem several months ago, and this procedure provided by Mike G fixed the problem for me.

Reset your 12V battery learned values to ensure the battery is fully recharged while driving.

Here's how to do that:
Press the start button without stepping on the brake.
Flash the high beams with the stalk five times, and then step on the brake pedal three times, and after that, check the red battery icon on the instrument panel to see that it flashes three times. And then shut the ignition off. And then you can turn the car fully on and drive off. Your 12V battery should then fully recharge (if it wasn't doing that before).

Do I also wave a chicken over my head three times while standing on one foot?

 

[Auto Motive]

Getting "Service 12v battery soon" message. How much should this cost at a dealership?

Check warranty first and if your dime look to the Optima.

 

[DaveQ]

Recommend you try a service charge on it first before replacing it. See details here:

Thread 'How to Recondition/Service Your 12V Battery'

If that doesn't work, then you can try to reset the BMS only after the battery is fully charged for 8+ hours.

Performed the procedure

I had this problem several months ago, and this procedure provided by Mike G fixed the problem for me.

Reset your 12V battery learned values to ensure the battery is fully recharged while driving.

Here's how to do that:
Press the start button without stepping on the brake.
Flash the high beams with the stalk five times, and then step on the brake pedal three times, and after that, check the red battery icon on the instrument panel to see that it flashes three times. And then shut the ignition off. And then you can turn the car fully on and drive off. Your 12V battery should then fully recharge (if it wasn't doing that before).

Performed the procedure as directed. Drove for awhile and now placed it on level 2 to charge. Thanks!

 

[jetermeyer]

I had this problem several months ago, and this procedure provided by Mike G fixed the problem for me.

Reset your 12V battery learned values to ensure the battery is fully recharged while driving.

Here's how to do that:
Press the start button without stepping on the brake.
Flash the high beams with the stalk five times, and then step on the brake pedal three times, and after that, check the red battery icon on the instrument panel to see that it flashes three times. And then shut the ignition off. And then you can turn the car fully on and drive off. Your 12V battery should then fully recharge (if it wasn't doing that before).

Can I do this at 80% charge or does it have to at 100%

 

[Maquis]

Can I do this at 80% charge or does it have to at 100%

Are you talking about the HVB SoC? It shouldn’t matter as long as it’s not critically low.

 

[jetermeyer]

sorry, was asking about doing the BMS reset. My 12v won't charge above 80%.

 

[mkhuffman]

sorry, was asking about doing the BMS reset. My 12v won't charge above 80%.

How do you know your LVB won't charge above 80%? Just wondering, not accusing...

 

[jetermeyer]

I've left the car on with fan on 5 for hours. it started at 57% and made it to 80% after 3 hrs. I shut the car off and then the next day did the same thing and according to the Ford.com site it still only registered at 80%. I made to refresh Forld pass and the site but I never see it above 80%. I have been getting messages in Ford pass for a while that LVB needed to be charged. I have not taken it for a long trip in a while. Most I have driven in past couple of weeks is for 30 minutes. So I have not need to charge it for any length of time recently. I usually charge to 90% but just charged it to 100% so it would be on the charger longer. Still did not register above 80%. So I figured I would do the BMS reset to see if that did anything but don't want to do that if it will cause problems based on the current charge percentage. Currently on 6.6 of OTAs if that makes a difference.

 

[mkhuffman]

I've left the car on with fan on 5 for hours. it started at 57% and made it to 80% after 3 hrs. I shut the car off and then the next day did the same thing and according to the Ford.com site it still only registered at 80%. I made to refresh Forld pass and the site but I never see it above 80%. I have been getting messages in Ford pass for a while that LVB needed to be charged. I have not taken it for a long trip in a while. Most I have driven in past couple of weeks is for 30 minutes. So I have not need to charge it for any length of time recently. I usually charge to 90% but just charged it to 100% so it would be on the charger longer. Still did not register above 80%. So I figured I would do the BMS reset to see if that did anything but don't want to do that if it will cause problems based on the current charge percentage. Currently on 6.6 of OTAs if that makes a difference.

You might not have a charger or power supply, and really it shouldn't be necessary to have those, but I would try charging the LVB manually first before resetting the BMS. Based on what Lee posted, it seems you could end up resetting the the BMS so that it thinks 80% is 100%, which could cause lots of problems later. It may get rid of your errors and mask the problem instead of fixing it.

Sponsored