Now on the 3rd 12 V battery, still under warranty

[Dean Hale]

My 2023 Maverick hybrid is now on its 3rd 12V battery. Each replacement has been under warranty. The dealer kept the vehicle for 3 business days, plus the weekend. I told the dealer that it was fine to keep the vehicle for a few days and shared my knowledge of factory bulletins re challenges with the 12V system. The first replacement battery is just 11 months old. On the first day, it tested OK. On the second day they did some reprogramming and kept the truck over the weekend. On Monday, the battery tested as bad and was replaced with another flooded battery. The dealer advised that the vehicle's programming has been updated to the latest factory advice/bulletins. I drove the truck home (3 miles) at 5pm. At 11pm, I used my high-end electronic VOM to check the voltage. 11.71 volts. That is worse than the battery that was replaced. We will see!

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[OleFordGuy]

So did thy ever fully charge the new battery before installing it, go through the BMS Reset procedure and then let the truck sit with doors locked, undisturbed for 8 hours like the manual states? Also by now they should be installing AGM batteries not flooded. IMO the real issue is ford needs to fix the POS battery charging software code that’s not properly charging the batteries. Until they get their head out of the sand and correct that, flooded and AGM batteries will continue to deteriorate and fail.

 

[Glen Baker LLC]

So did thy ever fully charge the new battery before installing it, go through the BMS Reset procedure and then let the truck sit with doors locked, undisturbed for 8 hours like the manual states? Also my now they should be installing AGM batteries not flooded. IMO the real issue is ford needs to fix the POS battery charging software code that’s not properly charging the batteries. Until they get their head out of the sand and correct that, flooded and AGM batteries will continue to deteriorate and fail.

It would not surprise me if some dealerships are unaware of the full procedure. I'll bet the dealership never bothered to charge the OP new battery.

I hope this helps. Perhaps, some owners will understand the whole procedure a little bit better reading this from the manual.

 

[TheSEARCH]

I agree sounds like they put a low battery even though new into it. My battery was replaced under warranty last August and the service bulletin on AC was done too. My voltage at cig lighter was over 13 volts when truck was off. Over time it has lowered down to low 12's. I then charged battery for 10 hours and its back over 13 volts .

My 2023 was just 2 years old last august. Had I not charged it on regular basis I most likley would have been through a few batteries too. I just charge mine once in a while to make it last longer. YES I shouldn't have too. BUT I cant use a loaner while it sits at dealer to haul kayaks I use all summer. So I keep battery going as long as possible. Sucks but that is where the Mav hybrid is now.

 

[johnDeere]

My 2023 Maverick hybrid is now on its 3rd 12V battery. Each replacement has been under warranty. The dealer kept the vehicle for 3 business days, plus the weekend. I told the dealer that it was fine to keep the vehicle for a few days and shared my knowledge of factory bulletins re challenges with the 12V system. The first replacement battery is just 11 months old. On the first day, it tested OK. On the second day they did some reprogramming and kept the truck over the weekend. On Monday, the battery tested as bad and was replaced with another flooded battery. The dealer advised that the vehicle's programming has been updated to the latest factory advice/bulletins. I drove the truck home (3 miles) at 5pm. At 11pm, I used my high-end electronic VOM to check the voltage. 11.71 volts. That is worse than the battery that was replaced. We will see!

Bummer to read, I have a 23 mav hybrid, and seen the sleep message too.
Sound like they did the ACCM update for the unknown current draw.
And after a couple of days, the battery tested bad, there still must be a unknown draw.

And you are still are seeing low voltage after sitting.
For the BMS to work correctly, the battery must be fully charged so it know what fully charged looks like, when it does its learning job.

I have a volt amp meter connected to my battery, and one day I noticed after driving to work (15 minute drive) that the battery was still charging at 10 amps and 15 volts.
Now that is after I fully charged the battery the day before.
I know after seeing that reading after the drive to work that the unknown draw was there draining my battery.
I said heck with this testing, hook up my second battery under the back seat, charge them both, reset the BMS, did the BMS learning that night, and noticed when i got to work, I was only charging at 2 amps at 15 volts.
Interesting the truck thinks the SOC was at 70%. after I got to work. 80% after I charged the batteries.
I guess I will still wait to hear some good news before I take my hybrid to the dealer.


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[TheRealEman]

I find these posts very informative. I recently had my factory 12v replaced by an agm 12v for free. My truck was built in October 2024, though I bought it new March 2025. It always started but I had several deep sleep and battery saver warnings. Daily driver, though admittedly mostly local. Averaging 1,000 miles a month.The dealer said my factory battery tested at 11v. Is it solved? We’ll see.

 

[MavTed]

It would not surprise me if some dealerships are unaware of the full procedure. I'll bet the dealership never bothered to charge the OP new battery.

I hope this helps. Perhaps, some owners will understand the whole procedure a little bit better reading this from the manual.

Thank you.

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