2024 having 12v low voltage battery issues with my Hybrid...

[HSBII]

Bought my Maverick in May in July I noticed that my interior dome lights were not coming on and from all the battery post on here that I've read I knew the 12v battery was in a low voltage state and the truck was disabling certain circuits. So I checked it and it was a 11.5v... Got out my old ass battery charger and in about 4 hours it was charged up to 12.8v... Fast forward to today opened the door and once again I noticed no dome lights, so I checked the voltage at the battery and it was 11.7v.. So obviously the trucks charging system is not keeping the main battery charged up, we drive it pretty much every day have around 5k on it now that works out to around 1000 mile per month or close to 240 per week give or take.. So when the POS Ford Pass app tells you to drive the truck more... How many more does one need to drive it to keep the battery happy...
Anyway my real question is how does going to a AGM really help if the trucks charging parameters are still the same.. The difference between a flooded and AGM's voltage state of charge are very close the AGM is only a few tenths higher??

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[Solaryellow]

Any issues with starting the truck?

 

[HeyBales]

Check for dealer installed, and hidden, location device.
Hopefully under the drivers dash where the OBD2 plug is, and easier to see.

Paperwork may even have a line about free theft recovery feature!

 

[Packer Bill]

Many Hybrid owners have bought a third party AGM battery (Ford does not make one for the hybrid) to solve their battery issues like yours. If you do a search, you will find recommendations for battery replacement.

 

[HSBII]

Any issues with starting the truck?

Nope no issues starting only clue was the dome light…

Check for dealer installed, and hidden, location device.
Hopefully under the drivers dash where the OBD2 plug is, and easier to see.

Paperwork may even have a line about free theft recovery feature!

No devices added…

 

[HSBII]

Many Hybrid owners have bought a third party AGM battery (Ford does not make one for the hybrid) to solve their battery issues like yours. If you do a search, you will find recommendations for battery replacement.

Yes and thanks been there already my question is how does just going to a AGM solve the issue?
If the trucks not able to charge a flooded battery then how is it supposed to charge a AGM…..

 

[HeyBales]

You are correct with the problem with any battery.
The usual comment is the AGM is better than cheap Motorcraft, and can take the low charge states better, but doesn't change the BMS charge amounts and rates.
Nor will it stop a problematic draw.
Some have commented the issues returned just less frequently after a good while.

Now - the BMS setup is for AGM by default - just in case that causes different charging and learning the battery after a reset to a better effect. Or it may be an option used in other vehicles this BMS is used in, but nothing is done in this truck with the info. Never seen that clearly tested out by anyone.

Do you have good ATT cell signal where truck is parked most the time?
Poor signal uses more power than good, no signal is worse, it'll keep looking.
Mine was made Feb 24, and while it does get stupid low 50% SOC and only up to 65%, I've yet to see it have issues with lights or warnings.
Only issue is it drops the accessory port power sooner than 60 min after truck turnoff when it's below 60% SOC. So my phone charger plugged in looses it during those times for the phone I leave in truck for Forscan Lite.

 

[Maverick2022XL]

Bought my Maverick in May in July I noticed that my interior dome lights were not coming on and from all the battery post on here that I've read I knew the 12v battery was in a low voltage state and the truck was disabling certain circuits. So I checked it and it was a 11.5v... Got out my old ass battery charger and in about 4 hours it was charged up to 12.8v... Fast forward to today opened the door and once again I noticed no dome lights, so I checked the voltage at the battery and it was 11.7v.. So obviously the trucks charging system is not keeping the main battery charged up, we drive it pretty much every day have around 5k on it now that works out to around 1000 mile per month or close to 240 per week give or take.. So when the POS Ford Pass app tells you to drive the truck more... How many more does one need to drive it to keep the battery happy...
Anyway my real question is how does going to a AGM really help if the trucks charging parameters are still the same.. The difference between a flooded and AGM's voltage state of charge are very close the AGM is only a few tenths higher??

First off did you check to see if the battery itself is no good?

Second how did you charge the battery. did you hook the negative to the battery terminal or chassis ground or engine block?

Third have you done any electrical modifications like a sound system, inverters, etc. ?

 

[HSBII]

First off did you check to see if the battery itself is no good?
No as I do not have a load tester...

Second how did you charge the battery. did you hook the negative to the battery terminal or chassis ground or engine block?
Connected both + - to the battery itself under the seat...

Third have you done any electrical modifications like a sound system, inverters, etc. ?
Nope only electrical mods I have done was I added a switched light to the glove box and a set of DD fog lights which is also manually switched...

 

[Maverick2022XL]

First off just get it tested at an auto parts store, they usually will do it for free. That will rule out the battery being bad.

As far as your electrical mods goes did you wire in the negative connections directly to the battery terminal or somewhere further up?

As far as you charging the battery that is user error and causing some of the issues after the first problem popped up. I'll explain in separate post why but the short answer is you need to charge the battery so current goes through the BMS sensor not behind it. The negative needs to be connected to a chassis ground or engine block. To correct what you do is reset the BMS and let the BCM then relearn the battery's charge status which requires the truck be key off, doors locked for about 8 hours, page 311 in the owners manual explains how to do it manually.

 

[HSBII]

First off just get it tested at an auto parts store, they usually will do it for free. That will rule out the battery being bad.
Will see if I can borrow a load-tester...

As far as your electrical mods goes did you wire in the negative connections directly to the battery terminal or somewhere further up?
Yes both additions have the grounds to chassis.

As far as you charging the battery that is user error and causing some of the issues after the first problem popped up. I'll explain in separate post why
Yes please explain...
but the short answer is you need to charge the battery so current goes through the BMS sensor not behind it. The negative needs to be connected to a chassis ground or engine block. To correct what you do is reset the BMS and let the BCM then relearn the battery's charge status which requires the truck be key off, doors locked for about 8 hours, page 311 in the owners manual explains how to do it manually.

Looked at the manual and read about resetting the BMS I'll do that , thanks for the insight..
So why does the BCM need to relearn when the BMS is what is controlling the batteries state of charge??..

 

[MavTime]

I installed this trickle charger between the + terminal and the body ground under the battery so that way the charge goes through the black block BMS sensor on the battery ground terminal:
https://www.amazon.com/gp/product/B07W3QSMF9/

It sits on passenger side in the small cubby between rears seat and the door jamb. So I can just hang the cord out with the door closed and leave it to charge up over a weekend with a post-it note on the shifter. Mine will go a month or so between needing to be charged back up, so it isn't that much of a pain.

My understanding is it is a lower quality Ford battery, and a better battery or AGM will just give you a larger "bucket" of power that will eventually deplete due to the way the DC to DC charging works. So with varying use cases and drive times in the truck some people don't see the problem return, but some do.

 

[Maverick2022XL]

As best I can explain the BMS issue is this. First off the BMS if it is the same as the ecoboost engines should be the black box on the negative cable right before the battery terminal connector. It will also have sensor connector and wire which among other things allows it to talk to the BCM module. With the information it monitors i.e. current, voltage and voltage temp it passes that along to the BCM which uses that to determine the battery's charge state whether it is 100%, 90% etc. Now if the current from a charge goes around it on the terminal the BCM can't update that correctly. If that state got too low and it started soft offing circuits like the dome lights even if you do charge the battery it will still keep doing it. The BCM has no way of knowing otherwise. If it keeps doing that eventually even though the battery maybe charged it will think it is at a low enough level that hard off's start like permanent shut off of the auto start/stop system which can only be reneabled by reseting the BMS.

That is why the negative has to be connected somewhere before the BMS sensor not behind it when charging. The surefire way to fix that is to get the BCM to relearn the battery's charge status and in turn recalculate the battery's life. The only 2 ways I know that it does is when you change the battery or you reset the BMS.

 

[Timothyd]

Bought my Maverick in May in July I noticed that my interior dome lights were not coming on and from all the battery post on here that I've read I knew the 12v battery was in a low voltage state and the truck was disabling certain circuits. So I checked it and it was a 11.5v... Got out my old ass battery charger and in about 4 hours it was charged up to 12.8v... Fast forward to today opened the door and once again I noticed no dome lights, so I checked the voltage at the battery and it was 11.7v.. So obviously the trucks charging system is not keeping the main battery charged up, we drive it pretty much every day have around 5k on it now that works out to around 1000 mile per month or close to 240 per week give or take.. So when the POS Ford Pass app tells you to drive the truck more... How many more does one need to drive it to keep the battery happy...
Anyway my real question is how does going to a AGM really help if the trucks charging parameters are still the same.. The difference between a flooded and AGM's voltage state of charge are very close the AGM is only a few tenths higher??

Because of the posts here I bought a voltmeter that plugs into the cigarette lighter socket. It's very consistent and gives me peace of mind.

 

[HSBII]

I installed this trickle charger between the + terminal and the body ground under the battery so that way the charge goes through the black block BMS sensor on the battery ground terminal:
https://www.amazon.com/gp/product/B07W3QSMF9/

It sits on passenger side in the small cubby between rears seat and the door jamb. So I can just hang the cord out with the door closed and leave it to charge up over a weekend with a post-it note on the shifter. Mine will go a month or so between needing to be charged back up, so it isn't that much of a pain.

My understanding is it is a lower quality Ford battery, and a better battery or AGM will just give you a larger "bucket" of power that will eventually deplete due to the way the DC to DC charging works. So with varying use cases and drive times in the truck some people don't see the problem return, but some do.

As best I can explain the BMS issue is this. First off the BMS if it is the same as the ecoboost engines should be the black box on the negative cable right before the battery terminal connector. It will also have sensor connector and wire which among other things allows it to talk to the BCM module. With the information it monitors i.e. current, voltage and voltage temp it passes that along to the BCM which uses that to determine the battery's charge state whether it is 100%, 90% etc. Now if the current from a charge goes around it on the terminal the BCM can't update that correctly. If that state got too low and it started soft offing circuits like the dome lights even if you do charge the battery it will still keep doing it. The BCM has no way of knowing otherwise. If it keeps doing that eventually even though the battery maybe charged it will think it is at a low enough level that hard off's start like permanent shut off of the auto start/stop system which can only be reneabled by reseting the BMS.

That is why the negative has to be connected somewhere before the BMS sensor not behind it when charging. The surefire way to fix that is to get the BCM to relearn the battery's charge status and in turn recalculate the battery's life. The only 2 ways I know that it does is when you change the battery or you reset the BMS.

Thanks again for the info and sharing your knowledge....

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