How I “Fixed” Battery Drain

[Bones 615 Tennessee]

I bought my 25 hybrid XL on 11/28/2025 and couldn’t even test drive it as the AGM battery was dead. The salesman jumped it off a test drove it and bought it. They changed the battery, washed it and filled it up with gas and sent me on my way.

From my understanding, you are supposed to lock the doors for eight hours after resetting the BMS and I don’t think people are really doing it that way.

I bought a NOCO genius two maintainer,fully charged the battery reset the BMS,.and locked the doors for a day and a half. The truck just has 739 miles but so far I’ve not had any issues and I hope it stays that way.

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[HeyBales]

Oh Canada

Thought you were going to start singing there!

 

[HeyBales]

I bought my 25 hybrid XL on 11/28/2025 and couldn’t even test drive it as the AGM battery was dead. The salesman jumped it off a test drove it and bought it. They changed the battery, washed it and filled it up with gas and sent me on my way.

From my understanding, you are supposed to lock the doors for eight hours after resetting the BMS and I don’t think people are really doing it that way.

I bought a NOCO genius two maintainer,fully charged the battery reset the BMS,.and locked the doors for a day and a half. The truck just has 739 miles but so far I’ve not had any issues and I hope it stays that way.

New battery, that reset is indeed in the manual.

The other one not happening, or possibly unlikely.
Say tech does charge it and says good battery - do they leave it locked long enough to do the BMS Relearn? Unlikely - come and pick'er up ASAP!
I've yet to hear someone say they were told to go home and lock it overnight.
So all the garaged folks who don't lock the truck - no relearn after a charge per the manual, or perhaps almost never.

 

[Cancunbadlands]

Thought you were going to start singing there!

Sweet home Alabama

 

[Mavster Mechanic]

I pulled out the fuse for the modem.

Been fine for 42 months on the stock FLA battery.

Dome lights work for me every time.
Even after sitting a week.

 

[HeyBales]

I pulled out the fuse for the modem.

Been fine for 42 months on the stock FLA battery.

Dome lights work for me every time.
Even after sitting a week.

I'd include the daily drive time in there since there are so many infrequent or short mileage drivers.
Actually - some of them report no issues either!

 

[MrPnut]

I'm not giving up remote app start, fob doesn't reach from workplace to parking lot, or notifications from my Perimeter Plus Alarm.

My second battery started giving deep sleep notifications at around 11 months, same as the first battery.

Hard wired a loop connector end of a $15 trickle charger to come out through a spot in the fender well. Plug it in once a month or so.

Haven't filled out my rebate yet for buying a PHEV

https://a.co/d/eG4Mujk

For the less aware of us, could you take a picture of how you connected to the battery? Not certain what you mean?

 

[Gullzway]

For the less aware of us, could you take a picture of how you connected to the battery? Not certain what you mean?

I connected the end of the charger attachment to the jump points under the hood. A nut on the positive connection, and the negative post comes off, attach connector then re tightnen.

 

[MrPnut]

I connected the end of the charger attachment to the jump points under the hood. A nut on the positive connection, and the negative post comes off, attach connector then re tightnen.

Thanks! That makes sense now!

 

[nunucello]

I pulled out the fuse for the modem.

Been fine for 42 months on the stock FLA battery.

Dome lights work for me every time.
Even after sitting a week.

Which is the fuse for the modem ? Is it in the box under the glove box ? Thank You.

 

[HeyBales]

Which is the fuse for the modem ? Is it in the box under the glove box ? Thank You.

Yes. 11/12.


Identifying the Fuses in the Body Control Module Fuse Box

Item	Rating	Protected Component
1​	5 A​	Not used (spare).​
2​	5 A​	Not used (spare).​
3​	10 A​	Auto-dimming interior mirror. Image processing module A. Automatic high beam control.​
4​	10 A​	Ignition switch. Push button start switch. Key inhibit solenoid.​
5​	20 A​	Lock. Unlock.​
6​	10 A​	Moonroof. DC inverter. Driver door switch pack. Power slide rear window switch.​
7​	30 A​	Passenger door module.​
8​	5 A​	Parking assist control module. Trailer brake switch (gas).​
9​	5 A​	Not used.​
10​	10 A​	Extended power module.​
11​	5 A​	Telematics control unit module.​

 

[inline_five]

I'm now 100% convinced these are just crappy low end lead acid batteries.

I have treated mine with kid gloves. Parked in a garage 99.5% of its life. Nico genius 5 hooked up pretty much 24/7 except when driving. I've got 10,000 miles total on it and vast majority of them are highway trips of three hours, four days sitting, and three hours back home. Repeat that once every two months or so. Then the rest of the time it sits in the garage and does two errands a week at best.

Voltage after driving home three hours is now 12.2x after sitting just two days. I've decided to stop charging it while in my garage because I can see where this is going and I want a new battery from Ford.

Crazy how terrible these are. My cheapie lead acid Walmart special is now six years old and sits outside 24/7 in hot and cold weather and still starts my airport car. Car sits for 4-10 days at a stretch.

 

[Darryl]

2024 XL Hybrid here!

I don’t have data that shows the issue I had, but many of you are all too familiar with the following evidence of a problem:

Within the first 10K miles:

• Dozens of battery-saver mode notifications. Almost always overnight / very early AM.
• Quite a few resulted in no noticeable issue or change.
• After two of them, woke up to a dead battery. Lucky my jumper pack got me going again.
• The dealer replaced my infotainment system - said this may be causing drain.
• After one of them / after infotainment replacement, my truck had a dead battery. Jumper did not start it and even after a trickle, I was in “limp mode”. Towed to dealer and the battery was apparently just fine and wouldn’t even replace it with another awful stock battery.
• After the last one, had another dead battery but jumper did start it back up.

FYI - I drive pretty much 50 / 50 town and highway. I know for a fact that before one of the dead batteries, I commuted to and from a destination about 1.5 hours away (3 hour round trip).

I took matters into my own hands at this point.

I have had no issues in the past 20K miles (just crossed 31K total) by doing the following:

• Turned off all connectivity. Updates, FordPass, WiFi, Bluetooth, etc. Anything that I could turn off - went off. I personally don’t miss any of it. All the application was doing for me was giving me battery-saver notifications! I would try this even if you like the features just to isolate the issue.
• Installed an AGM myself and reset the BMS.

I was also trickle charging with a NOCO 5. Not every day. But probably every week, as it was just so easy. Great little device. Definitely if I knew it would be sitting for 3+ days.

That said, I wanted to see if I needed to trickle. Or if my AGM and turning off connectivity worked. Below is data from the past week:

#	Date / Time (from app)	Voltage	Temp	Condition / Notes
1	Jan 05, 2026 17:38	13.14V	35.6°F	Parked while on NOCO (charging/float)
2	Jan 06, 2026 07:25	12.72V	32.0°F	Overnight NOCO, then ~2h rest (locked, fob away)
3	Jan 06, 2026 07:27	15.13V	32.0°F	A few minutes after start (active charging)
4	Jan 06, 2026 16:06	12.79V	48.2°F	After ~1 hr drive, then ~2h rest (locked, fob away)
5	Jan 07, 2026 08:19	12.75V	37.4°F	AM, no NOCO overnight (locked, fob away)
6	Jan 08, 2026 09:17	12.63V	37.4°F	AM, no NOCO overnight again (locked, fob away)
7	Jan 08, 2026 19:11	12.88V	59.0°F	After driving quite a bit, then ~1+ hour rest (locked, fob away)
8	Jan 09, 2026 06:56	12.74V	33.8°F	AM, no NOCO overnight (locked, fob away)
9	Jan 09, 2026 13:30	12.74V	53.6°F	PM after long drive, then ~2+ hour rest (locked, fob away)
10	Jan 09, 2026 17:35	12.73V	53.6°F	PM after short drive, then ~3h rest (locked, fob away)
11	Jan 10, 2026 16:54	12.85V	50.0°F	After multiple short trips (errands), then >3h rest (locked, fob away)
12	Jan 11, 2026 12:40	12.61V	44.6°F	AM reading (resting)
13	Jan 11, 2026 18:23	12.81V	51.8°F	After short round trip in town, then ~2h rest (locked, fob away)

The point of my post is this - AGM + turn off connectivity seems to work. Further, I believe something in the connectivity is the drain. Anyone have any comments or disagree? Battery seems to be charging itself as it should now. Even after short trips.

Small sample size, I know. But good sign.

I’ll likely still trickle, as I already have it set up in the garage now and it’s so easy to just plug in. But pretty confident now I don’t need to.

We're dealing with a problem child at our dealership. We are involved directly with a Ford field service engineer. We happened to catch the intermittent draw in action. He had me to disconnect power from the TCU (the module response for communication with the outside world) . Thus far it seems that it may be the culprit. So we may end up replacing it to see if it has an internal fault that causes it to wake up other modules repeatedly to and not allow them to go back to sleep. quickly. By you disabling updates and other connectivity features, you are minimizing opportunities for it to awaken other modules. Of course you should not need to do those things. If what you did works. You may want to experiment by enabling those features again to see if the problem reappears just fr curiosity. The customer is negotiating a buyback. So they won't let me proceed with replacement until that's resolved. But I hope that Ford allows me to replace the module regardless of the outcome of the buyback situation.

 

[Darryl]

All this does is delay the inevitable. There are so many phantom drain issues, from the LTE modem calling home to Ford and the nearest dealership, along with poor charging software, and a small battery. Even with the app and updates disabled after 4 days even with regular driving (1 hour 5 days a week), I still get battery saver by day four after using a battery maintainer.

Some have said pulling the fuse for the LTE modem helps too. There is also a software update for the AC that supposedly doesn’t shut off sometimes that is supposed to help. I just manually turn off the HVAC system before shutting off the truck, seem to have the same effect and helps a little.

If the AC is the issue, turning it off doesn't actually help because in the vehicle where it's the source of the problem, it sometimes just doesn't go to sleep because it was still awake even if not being used. Therefore , I recommend getting the update done especially if still under warranty. It doesn't help every vehicle. But it does help a LOT of them. .

 

[icegradner]

If the AC is the issue, turning it off doesn't actually help because in the vehicle where it's the source of the problem, it sometimes just doesn't go to sleep because it was still awake even if not being used. Therefore , I recommend getting the update done especially if still under warranty. It doesn't help every vehicle. But it does help a LOT of them. .

Just Ford extended warranty, by the time that update came out bumper to bumper was done.

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