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

[JAFO]

I didn't read any of the responses and I am sure someone probably already stated the obvious, but the battery management module only charges the 12volt battery to 12.3VDC. It only takes a couple days sitting and the 12volt battery will be depleted to 11.7vdc and be in sleep mode. To keep the Mav from going into sleep mode when the vehicle sits for days, hook up a 10amp smart charger. I refer to my 2023 Hybrid Mav as a Plug in Hybrid since I have to keep it plugged in to keep it charged.

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[Old Sweet]

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??

My '24 displayed the same 12v battery issues on inspection the dealership found the battery was defective. The battery was replaced by dealership and the problem solved.

 

[CroweMag55]

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.

Wouldn't hurt if you posted pic of how yours is connected..

 

[MMDavis]

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.

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