Low 12V battery voltage causing issues? (Update: Yes)

[Highway 11]

I've been having the weirdest issues with my truck as we've gotten into winter. All of these issues started in November. I've had my truck since January 2023.

- The folding gearshift won't return to its normal position unless the truck is powered on and running. It used to return up anytime the button was pressed.
- The gearshift sticks in drive and needs multiple presses to the shift release (if not it'll eventually release after 5-10 seconds) after the vehicle has been parked for an extended period of time.
- Occasionally I'll get a phantom trailer brake or brake system fault which will clear immediately.
- The windows occasionally will start bouncing back down requiring a reset with the switches.
- Occasionally Fordpass will not allow me to connect to the truck due to deep sleep.
- There is a DTC in the IPC when in engineering mode that says C55400, which doesn't return to anything.

The truck is booked in for a gear shift replacement, but it doesn't feel like a mechanical issue. I was watching a video on how to reset my windows after a night shift where it was said the issue was caused by a low battery. Plus there was another thread here about a folding shifter being stuck down and requiring a battery charge. But on the other hand, I've never had an issue with OTAs.

I'm curious if all of the above could be caused by a battery being low on voltage? I threw the truck into engineering mode real quick (I just finished a 12 hour night shift, I promise I'll do it properly when I wake up) and saw the battery voltage when off was 12.4V after a 15 minute drive. Until recently I had a dashcam running in parking mode that would shut off at 12.2V (which seems dumb in retrospect). That's been corrected to 12.5v shutoff and I think I may just forgo the parking mode.

Questions:

• I plan on adjusting the SOC up to 95% through Forscan to see if there's an improvement. Or should I just skip that and go pick up an aftermarket H8 battery or try my luck with another OEM battery?
• Could all of the above be explained by a battery issue? Or do I have the most unlucky Friday build ever?
• I know a lot of defective batteries are passing checks at dealerships. What should I be looking for to determine if my OEM battery is defective?

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[FirstFord]

There are countless posts and threads on this forum regarding strange, unusual, inexplicable behavior with these trucks, and in the vast majority of time the solution/explanation seems to be centered around low battery SOC and/or defective battery. There are a lot of experts on this forum (of which I am not one of them) so I cannot conclusively state that I know as a fact that the root cause of your experiences has been the battery. But all that being said, I'd just get yourself an aftermarket H8 AGM battery and then be done with it.

 

[nitrobass24]

Yes if you have electrical gremlins a new Battery will most likely fix it. If you have a trickle charger you could try charging it up and see if you can get your current one to behave better, but if not just spend the $180 for a new one and call it a day.

 

[Kurt V]

I've been having the weirdest issues with my truck as we've gotten into winter. All of these issues started in November. I've had my truck since January 2023.

- The folding gearshift won't return to its normal position unless the truck is powered on and running. It used to return up anytime the button was pressed.
- The gearshift sticks in drive and needs multiple presses to the shift release (if not it'll eventually release after 5-10 seconds) after the vehicle has been parked for an extended period of time.
- Occasionally I'll get a phantom trailer brake or brake system fault which will clear immediately.
- The windows occasionally will start bouncing back down requiring a reset with the switches.
- Occasionally Fordpass will not allow me to connect to the truck due to deep sleep.
- There is a DTC in the IPC when in engineering mode that says C55400, which doesn't return to anything.

The truck is booked in for a gear shift replacement, but it doesn't feel like a mechanical issue. I was watching a video on how to reset my windows after a night shift where it was said the issue was caused by a low battery. Plus there was another thread here about a folding shifter being stuck down and requiring a battery charge. But on the other hand, I've never had an issue with OTAs.

I'm curious if all of the above could be caused by a battery being low on voltage? I threw the truck into engineering mode real quick (I just finished a 12 hour night shift, I promise I'll do it properly when I wake up) and saw the battery voltage when off was 12.4V after a 15 minute drive. Until recently I had a dashcam running in parking mode that would shut off at 12.2V (which seems dumb in retrospect). That's been corrected to 12.5v shutoff and I think I may just forgo the parking mode.

Questions:

• I plan on adjusting the SOC up to 95% through Forscan to see if there's an improvement. Or should I just skip that and go pick up an aftermarket H8 battery or try my luck with another OEM battery?
• Could all of the above be explained by a battery issue? Or do I have the most unlucky Friday build ever?
• I know a lot of defective batteries are passing checks at dealerships. What should I be looking for to determine if my OEM battery is defective?

I had a lot of weird things going on with my 2023 Powerboost, all due to low battery. There's a constant drain on these things. If I'm not going to drive it for a while, I put it on charge using a smart charger and that stopped all of my issues.

 

[Spiffy]

My truck is on dealers lot now. Last night I got message that truck is in deep sleep and I can't connect with fordpass.
A month ago I was doing some FDRS work and had a charger on it but wasn't providing enough voltage. I let the SOC of the 12v battery get to low and all hell broke out. Brake issues, great shift issues. Failed modules. Truck was bricked. I let the charger on overnight and Jesse did some magic and I got it back.
I have been having these 12 vollt soc issues lately. Now that it's at the dealer/service and in deep sleep is this a good time to have them look?

 

[Highway 11]

I went out today after letting the truck sit for six hours. Engineering mode showed the battery voltage at 11.9V.

11.9V!

So I did a thing.

It's too dark to install tonight, so we'll see how this goes tomorrow. My plan is swap, reset the BMS system, increase SOC to 90% in Forscan, and shut off parking mode on my dashcam.

 

[FORDTEXAS]

I went out today after letting the truck sit for six hours. Engineering mode showed the battery voltage at 11.9V.

11.9V!

So I did a thing.

It's too dark to install tonight, so we'll see how this goes tomorrow. My plan is swap, reset the BMS system, increase SOC to 90% in Forscan, and shut off parking mode on my dashcam.

is resetting BMS system a must or optional?

 

[Highway 11]

is resetting BMS system a must or optional?

I think it's recommended after swapping batteries.

 

[FORDTEXAS]

I think it's recommended after swapping batteries.

is it easy to do or?

 

[Zappy]

I did this swap a week ago. My auto stop/start is finally working again lol.

 

[Highway 11]

is it easy to do or?

Don't quote me, but I believe in accessory you flick your momentary high beam 5 times, hit the brake three times, and wait for the battery light to flash three times.

I did this swap a week ago. My auto stop/start is finally working again lol.

Did you end up getting the updated battery jacket? I'm tempted not to given it's been rodent bait so far. There's just something outlandish about a truck having space for a battery two sizes larger than stock, and having issues because the batteries aren't up to snuff out of the gate.

 

[FirstFord]

is resetting BMS system a must or optional?

My Owner’s Manual presents it as a requirement. If I recall correctly, it also states that battery replacement is the only time the BMS should be reset. It is not difficult - the procedure is in the Owner’s Manual.

Just a consideration: anytime I replace a battery, I put a charger on it (a "smart charger") first, before I even crank the engine over. This ensures that everything is up to snuff from the start.

 

[Highway 11]

OEM battery was reporting 11.8V - 11.9V today. Remote start was getting spotty, and I had a trailer brake warning flash and disappear which wasn't a good sign in my books. Started fine though.

Swapped it over this afternoon just before a rainstorm. Had to adjust the positive terminal cover a bit to sit correctly but apart from that it was a seamless swap. Started up without an issue and I adjusted the SOC to 95%, turned off dashcam parking mode, and reset the BMS. While I was in Forscan, I also reset the gear shift module just to make sure it had the best chance of working correctly.

So far,

• Folding gear shift folds and unfolds with the engine off.
• The shift release solenoid releases instantly and forcefully when the button is pressed.
• No phantom warnings, no window bounce, no DTCs, no deep sleep, nothing else.
• Truck was sitting at 12.8V after four hours of being parked.

I'm thrilled, to say the least. Fingers crossed that this isn't just a one off and the truck continues to be problem free. Ironically my Subaru Outback died tonight. OEM battery there is notorious for poor quality as well. Back to Costco I go...

 

[Highway 11]

Update:

Plugged Forscan in today and checked SOC% through the day. All results were in the 80s. I did lower the target SOC to 90% after reading through the BMS thread. None of the quirks have surfaced. Shifter continues to work smoothly and at this point I'm confident I'm cancelling my warranty appointment to have it replaced.

 

[Northguy]

Update:

Plugged Forscan in today and checked SOC% through the day. All results were in the 80s. I did lower the target SOC to 90% after reading through the BMS thread. None of the quirks have surfaced. Shifter continues to work smoothly and at this point I'm confident I'm cancelling my warranty appointment to have it replaced.

Thanks for sharing your journey here. I have almost the same truck except 3.5l. I have had issues with my battery which I have managed with a BMS reset (twice) and charging occasionally. I may just replace the battery for piece of mind (my truck sat for almost 4 months on various holds so have not been confident with the battery). Hope the battery change allows u to have confidence in your truck again.

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