12V Battery FAQ

[HughJazzol]

No, this is not correct. The 12V battery is charged in the following situations:

1. When the car is ON (fully ON, accessories mode doesn't count)
2. While the HV battery is being charged
3. When the on-board computer determines the 12V battery has dropped below a certain threshold and the high voltage battery is not itself very low in charge (above 15%, as a rough approximation)

So this implies three more things. If you think your 12V battery needs to be charged more, you can:

1. Leave your car ON for longer, even if you're not driving it (i.e. by leaving it in a secure location like a garage while ON and auto-off disabled)
2. Slow down your charging - i.e. if instead of charging at 48 amps you can charge at lower speeds with a programmable EVSE (EV supply equipment) or even using the 120V Ford mobile charger
3. Take steps to make sure you have received recent software updates which makes the car maintain the 12V at a more robust voltage.

There's also a fourth option, if you are so inclined - you could pop off the plastic frunk covers and use a 12V battery charger directly, though this is probably overkill in almost all situations.

thank you Paul for your clarifications.
So, the 12v charges while the car is parked and charging. Cool.
"When the car is ON" - does it charge as we drive it? I assume so.

What steps can I or anyone take to make sure we've received the ECG 12V battery update? I just sat in my car, turned on and attached to WIFI, disabling and enabling the updates toggle switch. Another thread mentioned that doing so, may trigger updates from Ford. What else can we do?

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[Mach-Lee]

I should maybe update that is not as critical anymore, but I still think optimizing your charge to take at least 2-3 hours per session is a good strategy overall for 12V health. If you plug in and your car is done charging in 20 minutes, that’s not enough time to get the 12V topped off.

 

[HughJazzol]

I should maybe update that is not as critical anymore, but I still think optimizing your charge to take at least 2-3 hours per session is a good strategy overall for 12V health. If you plug in and your car is done charging in 20 minutes, that’s not enough time to get the 12V topped off.

Yes, that makes sense. Thank you.
So we need to aim for a looong 220v charge, from 40% to 80, for example. Or use the 110v charger or dial down a charging station so that the charge takes longer, but the car DOES NOT have to be ON.

 

[jmgreen]

Questions to the expert community:
Someone in this forum suggested a small battery tester that I got myself for easy checking of the battery’s heath status.
Amazon.com: KONNWEI KW208 12V Car Battery Tester, 100-2000 CCA Load Tester Automotive Alternator Tester Digital Auto Battery Analyzer Charging Cranking System Tester for Truck Marine Motorcycle SUV Boat : Automotive

This device distinguishes two types of AGM batteries:

• AGM flat plate
• AGM Spiral

What is the one that we use within the Mach E (I expect the flat plate type)?

Then I can chose various different standards for running the check. Which would be the most recommended one? Looking at the battery label I would guess CCA with a 380A setting.

• CCA: Cold Cranking Amps, specified by SAE&BCI, most frequently used value for starting battery at 0°F(-18°C).
• BCI: Battery Council international standard.
• CA: Cranking Amps standard, effective starting current value at 0°C.
• MCA: Marine Cranking Amps standard, effective starting current value at 0°C.
• JIS: Japan Industrial Standard, displayed on the battery as combination of the numbers and letters, e.g. 55D23, 80D26.
• DIN: German Auto Industry Committee Standard.
• IEC: Internal Electron technical Commission Standard.
• EN: European Automobile Industry Association Standard.
• SAE: Society of Automotive Engineers Standard.

This device allows an “in-vehicle” testing. But can I use the jump start points on the right hand side (i.e. with the battery current sensor between jump start point and negative battery terminal)? Or do I need to test directly at the battery terminals?

I know that testing shall be done once the car is in sleep (no further bus communication). Is 15min wait time sufficient, or shall I wait even longer to get into “deep sleep”?

Thanks in advance for your guidance.

 

[Mach-Lee]

Questions to the expert community:
Someone in this forum suggested a small battery tester that I got myself for easy checking of the battery’s heath status.
Amazon.com: KONNWEI KW208 12V Car Battery Tester, 100-2000 CCA Load Tester Automotive Alternator Tester Digital Auto Battery Analyzer Charging Cranking System Tester for Truck Marine Motorcycle SUV Boat : Automotive

This device distinguishes two types of AGM batteries:

• AGM flat plate
• AGM Spiral

What is the one that we use within the Mach E (I expect the flat plate type)?

Then I can chose various different standards for running the check. Which would be the most recommended one? Looking at the battery label I would guess CCA with a 380A setting.

• CCA: Cold Cranking Amps, specified by SAE&BCI, most frequently used value for starting battery at 0°F(-18°C).
• BCI: Battery Council international standard.
• CA: Cranking Amps standard, effective starting current value at 0°C.
• MCA: Marine Cranking Amps standard, effective starting current value at 0°C.
• JIS: Japan Industrial Standard, displayed on the battery as combination of the numbers and letters, e.g. 55D23, 80D26.
• DIN: German Auto Industry Committee Standard.
• IEC: Internal Electron technical Commission Standard.
• EN: European Automobile Industry Association Standard.
• SAE: Society of Automotive Engineers Standard.

This device allows an “in-vehicle” testing. But can I use the jump start points on the right hand side (i.e. with the battery current sensor between jump start point and negative battery terminal)? Or do I need to test directly at the battery terminals?

I know that testing shall be done once the car is in sleep (no further bus communication). Is 15min wait time sufficient, or shall I wait even longer to get into “deep sleep”?

Thanks in advance for your guidance.

Flat plate. But keep in mind these devices do not test battery capacity, only cranking amps. It’s possible for a battery to pass the cranking amps test but still be bad (fails a capacity test).

 

[MadMax69CA]

Hi,

I own a 2021 Mach E Premium AWD. I had an issue yesterday at home (thank god) while parked where I was trying the TPMS relearn procedure (several on-off) as one of the TPMS was no longer recognized (I have a TPMS Ford learning tool). That said, I got a red battery light & the red car with "!" light and the car would not go into D.

I tried several things but after 10-15 min, I was able to "start" the car and put it in D to drive back in the garage. My first thought was that the 12V battery was going bad. This morning, I plugged an OBD II tool to get error codes & 12V battery health. The only active code is the TPMS and here is my battery health.

I also tested the battery with a multimeter (after resting it 30 min) and got 12.69V. I am not the original owner but I do not think it was ever replaced (I have owned the car since 2.5 y). That said from what I can tell, the 12V is still in good health.

Any recommendations ?

 

[Fretless_5]

Aside from the content, the formatting of the concealed details is brilliant for finding the information that is relevant on demand. Thank you.

 

[RockinVs]

Aside from the content, the formatting of the concealed details is brilliant for finding the information that is relevant on demand. Thank you.

What? I is brain hurting.

 

[MadMax69CA]

Hi,

I own a 2021 Mach E Premium AWD. I had an issue yesterday at home (thank god) while parked where I was trying the TPMS relearn procedure (several on-off) as one of the TPMS was no longer recognized (I have a TPMS Ford learning tool). That said, I got a red battery light & the red car with "!" light and the car would not go into D.

I tried several things but after 10-15 min, I was able to "start" the car and put it in D to drive back in the garage. My first thought was that the 12V battery was going bad. This morning, I plugged an OBD II tool to get error codes & 12V battery health. The only active code is the TPMS and here is my battery health.

I also tested the battery with a multimeter (after resting it 30 min) and got 12.69V. I am not the original owner but I do not think it was ever replaced (I have owned the car since 2.5 y). That said from what I can tell, the 12V is still in good health.

Any recommendations ?

I spoke to my local garage technician. This problem apparently happen to him also when trying to do the TPMS relearn procedure. The Mach E probably did not like the 11 on-off of the vehicle ! He tested my battery and has over 500 amps ... still good

 

[Mach-Lee]

Hi,

I own a 2021 Mach E Premium AWD. I had an issue yesterday at home (thank god) while parked where I was trying the TPMS relearn procedure (several on-off) as one of the TPMS was no longer recognized (I have a TPMS Ford learning tool). That said, I got a red battery light & the red car with "!" light and the car would not go into D.

I tried several things but after 10-15 min, I was able to "start" the car and put it in D to drive back in the garage. My first thought was that the 12V battery was going bad. This morning, I plugged an OBD II tool to get error codes & 12V battery health. The only active code is the TPMS and here is my battery health.

I also tested the battery with a multimeter (after resting it 30 min) and got 12.69V. I am not the original owner but I do not think it was ever replaced (I have owned the car since 2.5 y). That said from what I can tell, the 12V is still in good health.

Any recommendations ?

Don't use the TPMS tool, just drive the car and it will auto learn the new wheels in about a mile or two. Using the TPMS tool is no longer necessary on 2020+ Fords.

You probably got into accessory mode which drains the 12V battery and it got too low. It will recharge, but you should still consider replacement soon as you are at the 4 year mark. You cannot reliably tell if the battery is good or bad using the scan tool.

 

[mkhuffman]

What? I is brain hurting.

Because AI often says things that don't make sense.

 

[RockinVs]

Because AI often says things that don't make sense.

But I checked their other messages and they don't seem like AI, just this message.

 

[Mach1E]

But I checked their other messages and they don't seem like AI, just this message.

Ever wonder if you’re the only one who ISN’T AI? ?

 

[Misterrobot]

@Mach-Lee Good Day Sir!

I took my second longest road trip. 186 miles round trip with my 23 Select AWD Std NCM Batt, Early Build. Used all my tools and lessons learned from you and had a great round trip without having to charge. The Ford trip planner was off about 10% on the estimated battery usage - on the good side so I had 24% SOC when I got home.

To the question: I was half way into the return trip on I-88 and I popped on the OBD2 reader and noticed that the 12V battery was at 12.0V with a 90% SOC. I think the 12.0V is the lowest I've seen it, but this was only my second time on a trip over 20 miles. Maybe 3rd trip, anyways the Mach e is my daily drive of 37mile round trip while charging at home. Not battery alarms ever.

Should I be worried? It was a nice day Sunday at Byron IL with temps near 90. Parked at the Bryon Dragway for about 7 hours popping into the car once to get some AC. Half the trip is curvy/hilly along the Rock River on 2 lanes roads, the other half is 70mph I-88.

Thank you for your insight and have a great day!

 

[Mach-Lee]

@Mach-Lee Good Day Sir!

I took my second longest road trip. 186 miles round trip with my 23 Select AWD Std NCM Batt, Early Build. Used all my tools and lessons learned from you and had a great round trip without having to charge. The Ford trip planner was off about 10% on the estimated battery usage - on the good side so I had 24% SOC when I got home.

To the question: I was half way into the return trip on I-88 and I popped on the OBD2 reader and noticed that the 12V battery was at 12.0V with a 90% SOC. I think the 12.0V is the lowest I've seen it, but this was only my second time on a trip over 20 miles. Maybe 3rd trip, anyways the Mach e is my daily drive of 37mile round trip while charging at home. Not battery alarms ever.

Should I be worried? It was a nice day Sunday at Byron IL with temps near 90. Parked at the Bryon Dragway for about 7 hours popping into the car once to get some AC. Half the trip is curvy/hilly along the Rock River on 2 lanes roads, the other half is 70mph I-88.

Thank you for your insight and have a great day!

That's a bit strange, I don't think I've seen below 12.6V while driving. You're sure it was that low and not a false OBD reading from the adapter? How long did that last? I wouldn't worry about it yet, that could be some odd software thing or some kind of decay test.

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