2025 Hybrid - Potential Battery Drain?

[Matso]

Any dealer who would allow a customer to drive off with a newly purchased vehicle and fails to disclose the installation of an OBD tracker is just plain disingenuous. A good customer relationship is rather important in their business and mutual trust is an essential element of that. I would be seriously insulted if my dealer pulled off a stunt like that. But after all these years of doing honest business together, I know that would never happen. It shouldn't happen anyway.

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[Darryl]

Darryl we all value your expertise, thank you. I have 25MY Lariet Hybrid, purchased April 25. I am not having 12v battery or sleep problems. Q. How can I tell if ACCM update has been preformed in my truck? Or any other module firmware updates? For reference, my truck has only been back to dealer once for the passenger airbag placard recall. Thanks.

If you bought it new and didn't bring it in specifically for the battery drain, then it hasn't been done. If you did bring it in for that reason, or bring it to ANY Ford dealership, they can look up the history and immediately see it it's been done. If you aren't having any symptoms, don't worry about it until the warranty is almost over. By then they may have a COMPLETE fix that works 100% of the time.

 

[KenE]

If you bought it new and didn't bring it in specifically for the battery drain, then it hasn't been done. If you did bring it in for that reason, or bring it to ANY Ford dealership, they can look up the history and immediately see it it's been done. If you aren't having any symptoms, don't worry about it until the warranty is almost over. By then they may have a COMPLETE fix that works 100% of the time.

Great advice Darryl, thanks as always. I subscribe to "If it ain't broke, don't try to fix it" advice. Our Mav just performs like a Timex watch, keeps on ticking. (Young folks probably never heard that commercial on B&W Tv).

If you bought it new and didn't bring it in specifically for the battery drain, then it hasn't been done. If you did bring it in for that reason, or bring it to ANY Ford dealership, they can look up the history and immediately see it it's been done. If you aren't having any symptoms, don't worry about it until the warranty is almost over. By then they may have a COMPLETE fix that works 100% of the time.

Great advice Darryl, if it ain't broke, don't try to fix it. Thanks again. Our Mav performs like a Timex watch, just keeps on ticking. Young folks probably never heard that commercial on B&W TV years ago.

 

[Neils Bohr]

I agree also that OP has a battery issue base on what he said is happening. I have seen batteries go bad with an internal short. They go dead all of a sudden and will not take a charge and will cause the battery charger to over heat.

As far as the quality bashing here thats been going on since I have been reading MTC it seems to be nothing more than the bashers opinion. I have yet to read an explanation as to why these are crap batteries. I have had my current battery tested at the dealer and a shop that sells batteries and my own home tester and it passed as OK. If the charging system in my Maverick is not charging the battery fully when I drive it the battery is going to slowly get drained down. That is what is happening. A slow drain down. I throw the charger on it and it charges right back up and is good for 10 days.

Wait another year and your battery will start to drain dead within a day or two. These hybrids have problems with parasitic drains that Ford can't fix this far. Their updates and AGMs don't work. I have done all that and problem remains


. If they can't fix in next six months it's goodbye to the mav and hello to the less efficient Honda Ridgeline. I need my car to start.

 

[Matso]

Parasitic draw has not been the primary issue in most cases. In fact I think it's quite rare. My '24 hybrid was in the service bay for a total of three months with no such draw ever detected. Many times the problem lies with a poorly matched 12v battery in a power hungry hybrid with a hundred mouths to feed. Other times it's reported to be an issue with the ACC module for which they offer a software update. Sometimes the update works, other times no. Then there are the outliers like me, where nothing could be found to explain the persistent undercharging and low SOC with the subsequent and frequently reported battery saver mode, aka "deep sleep". So in my case I opted for a buyback under the lemon law and received a FULL refund. Longer story but it worked out pretty good.
So it may be worth building the paper trail in the first year of ownership and tolerate some inconvenience, with the benefit of a BB should you need to take that road.

 

[HeyBales]

Wait another year and your battery will start to drain dead within a day or two. These hybrids have problems with parasitic drains that Ford can't fix this far. Their updates and AGMs don't work. I have done all that and problem remains


. If they can't fix in next six months it's goodbye to the mav and hello to the less efficient Honda Ridgeline. I need my car to start.

Nah - by that point it's a bad battery - just can't hold a charge.

The number of complaints of true parasitic draw - dead battery in a day or two - is rare.

With these cold days and low charging rates due to cold battery (some nicer battery charges have temp sensor - they won't charge if it's too cold either) - I've been driving at 48% Ford SOC scale, getting up to 55% rarely on longer sets of errands a day a week.
4 hr trip coming up Fri - be interesting if it goes to float charge at 55% as it was doing last week - which means even with 4 hrs - it can't fully charge. At this point likely a bad cell, so it won't attempt because battery can't accept a full charge anyway. And if it could - can't hold a charge either.

 

[Darryl]

Wait another year and your battery will start to drain dead within a day or two. These hybrids have problems with parasitic drains that Ford can't fix this far. Their updates and AGMs don't work. I have done all that and problem remains


. If they can't fix in next six months it's goodbye to the mav and hello to the less efficient Honda Ridgeline. I need my car to start.

Wait another year and your battery will start to drain dead within a day or two. These hybrids have problems with parasitic drains that Ford can't fix this far. Their updates and AGMs don't work. I have done all that and problem remains


. If they can't fix in next six months it's goodbye to the mav and hello to the less efficient Honda Ridgeline. I need my car to start.

The truth of the matter is that not all of them have this problem. And the ACCM update has fixed MANY of them. But there are a stubborn few that persist with the issue. The best chance for success is to simultaneously perform the Accm update, Test and FULLY charge the battery, and reset the battery monitor. Again, it doesn’t fix them all. But it’s fixed most. Hope yours is one of them. Ford tells us that they are still coming up with a fix. I suspect they know the so of the problem and are trying to to come up with a software fix rather than replacing what seems will be the AC compressor . The Crazy thin is that the mechanically almost identical escape doesn’t have this issue. Wonder if there’s a different supplier for the offending Maverick component

Parasitic draw has not been the primary issue in most cases. In fact I think it's quite rare. My '24 hybrid was in the service bay for a total of three months with no such draw ever detected. Many times the problem lies with a poorly matched 12v battery in a power hungry hybrid with a hundred mouths to feed. Other times it's reported to be an issue with the ACC module for which they offer a software update. Sometimes the update works, other times no. Then there are the outliers like me, where nothing could be found to explain the persistent undercharging and low SOC with the subsequent and frequently reported battery saver mode, aka "deep sleep". So in my case I opted for a buyback under the lemon law and received a FULL refund. Longer story but it worked out pretty good.
So it may be worth building the paper trail in the first year of ownership and tolerate some inconvenience, with the benefit of a BB should you need to take that road.

on the vehicle at our dealership that hasn been fixed, the issue is still a parasitic draw. But it’s intermittent. It may go several days with no draw with us thinking it’s fixed. Then we’ll drive it with it being 90% when we leave. But it will be down to 20% the next day. Thats the draw that won’t show up when we connect the test equipment Because it will be gone for the time being. Is it common? No. But it accounts for the highly vocal, justified criticism coming from an unfortunate few that have tried everything. With no success Who go through even the best batteries regularly. Those are the ones for whom ford has not figured a solution.

 

[Neils Bohr]

The truth of the matter is that not all of them have this problem. And the ACCM update has fixed MANY of them. But there are a stubborn few that persist with the issue. The best chance for success is to simultaneously perform the Accm update, Test and FULLY charge the battery, and reset the battery monitor. Again, it doesn’t fix them all. But it’s fixed most. Hope yours is one of them. Ford tells us that they are still coming up with a fix. I suspect they know the so of the problem and are trying to to come up with a software fix rather than replacing what seems will be the AC compressor . The Crazy thin is that the mechanically almost identical escape doesn’t have this issue. Wonder if there’s a different supplier for the offending Maverick component

on the vehicle at our dealership that hasn been fixed, the issue is still a parasitic draw. But it’s intermittent. It may go several days with no draw with us thinking it’s fixed. Then we’ll drive it with it being 90% when we leave. But it will be down to 20% the next day. Thats the draw that won’t show up when we connect the test equipment Because it will be gone for the time being. Is it common? No. But it accounts for the highly vocal, justified criticism coming from an unfortunate few that have tried everything. With no success Who go through even the best batteries regularly. Those are the ones for whom ford has not figured a solution.

Well the dealer just updated the software and reset all the modules two days ago in attempt to solve the drain issue which they can't find as it is intermittent. So far the car has been sitting for two days and no weak battery signal yet. Fingers crossed....I will update in a couple weeks. Once again I have a new AGM battery and did a proper charge and reset. And I did do the accm module update prior with no benefit.

 

[Darryl]

Well the dealer just updated the software and reset all the modules two days ago in attempt to solve the drain issue which they can't find as it is intermittent. So far the car has been sitting for two days and no weak battery signal yet. Fingers crossed....I will update in a couple weeks. Once again I have a new AGM battery and did a proper charge and reset. And I did do the accm module update prior with no benefit.

I hope it's solved. My 2025 showed a low battery on my app ONE time about two months ago. I purposely didn't do anything other than drive it in order to see if it would happen again. To be honest, I may have left the switch on after sitting and listening to the radio after I got home. And simply got out without turning the switch off. Anyway,. When I arrived at work (a 45 mile drive) , I did check the battery level, it was 95% . I won't update or do anything else unless it does it again . Besides, I can always update later for free since I have access to everything while at work. I'm not really concerned though because it would have happened again by now if it was an issue.

 

[Neils Bohr]

I hope it's solved. My 2025 showed a low battery on my app ONE time about two months ago. I purposely didn't do anything other than drive it in order to see if it would happen again. To be honest, I may have left the switch on after sitting and listening to the radio after I got home. And simply got out without turning the switch off. Anyway,. When I arrived at work (a 45 mile drive) , I did check the battery level, it was 95% . I won't update or do anything else unless it does it again . Besides, I can always update later for free since I have access to everything while at work. I'm not really concerned though because it would have happened again by now if it was an issue.

Sounds like you are ok. My battery would drain dead within a night of parking it in the cold

 

[Packer Bill]

When I arrived at work (a 45 mile drive) , I did check the battery level, it was 95% .

I thought Ford's BMS only charges the battery to 80%. Did you change the battery level using ForScan?

 

[Mavster Mechanic]

Interesting battery anomaly here.

My 2022 stock battery is now 40 months old. Has had low voltage ever since I first checked it at 6 months old.

Never holds a charge higher than 12.2v.
It's often in the high elevens first thing in the morning.

Self reported OBDII 12v SOC always hovers around 60%. And has been for 3 years. So I mostly ignore it. It doesn't mean much.

ALWAYS STARTS EASILY.
Has never not started. Has never been jumped.

New Years Eve I left my aftermarket fog lights on for over an hour with key off.

Voltage on ScanGauge when I returned was 11.2v. Remote unlock worked fine. Dome lights came on. Truck started normally.

On the 45 minute drive after, about 17 amps of charge was going into the 12v battery.
Self reported OBDII 12v SOC rose to 75%.

An SOC higher than I've seen in 3 years of normal driving.

Maybe lack of recharging properly is tied to lack of discharge?

Remember how NiCd batteries had "memory effect" and we were encouraged to do a deep discharge once in a while!?

Well; in the hybrids at least, the 12v battery almost never gets "exercised".

Maybe some periodic deeper discharge (but not too far) would be healthy?

Just an observation and some musings.

 

[SafetyGuy]

I thought Ford's BMS only charges the battery to 80%. Did you change the battery level using ForScan?

I will be looking forward to Darryl's reply!

As for charge levels I can say my 2025 Lariat usually charges to 100% as far as I have seen. (I just use nice little multimeter, nothing fancy and use the underhood connection boost points).

With engine power on, it is charging at over 14 volts and every time I check the 12 volt battery charge level after all the modules shut down, my battery is usually resting at around 12 68-12.71 volts.

I have done several battery thorough re-charge/conditioning cycles and then did the re-learn procedure so that the truck knows what a full battery looks like and now it charges the battery to its true full charge level.

I feel as soon as everyone gets a new Maverick, they should do a complete battery re-charge/conditioning and then the re-learn procedure. Could just be me of course.

Note-this doesn't deal with the sudden dead battery issues, only that it is a good idea to make sure your trucks battery is being charged properly.

Andy

 

[Darryl]

B

I thought Ford's BMS only charges the battery to 80%. Did you change the battery level using ForScan?

No. Haven't touched the truck other than to check the battery level. Cleared a stray code set when fog covered my front camera. 80% is. Actually the minimum that Ford recommends for us to perform certain tests and updates. Also the minimum at which start/ stop will work on EcoBoost and other vehicles equipped with start stop. Typically a vehicle will be at 85-90 if fully charged and all is well and settled in.

 

[Neils Bohr]

Sounds like you are ok. My battery would drain dead within a night of parking it in the cold

Well after dealer reset and updated the software on every module in the car one by one my parasitic drain this far seems to be gone. Let's hope that continues!

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