Do these 12v battery issues exist in the 2025 model?

[chl]

Any an all 12v lead acid batteries will last longer if on a maintainer when not in use.
The reason is sulfate build up on the plates.

If the battery is not fully charged to 100% after use, the sulfates that form as a result of the chemical process of releasing stored energy will not be driven off of the plates in the battery back into the electrolyte, and they become a permanent coating reducing the ability of the battery to deliver energy.

Over time the sulfate build-up will 'kill" the battery's ability to deliver energy.

A battery maintainer will top off the battery to 100% and avoid this problem, using a low current to avoid another potential battery issue - overheating leading to swelling, loss of electrolyte and out-gassing of hydrogen gas. That has been seen in some Lightnings as well as the early death.

If you don't use a maintainer, you might get 2-5 years out of an AGM battery depending of driving habits, etc., before needing to replace it. Maybe that's enough for some, but there are many Lightning system components that are critically dependent on the 12v battery system.

From Lightning owner reports here and elsewhere, the lower end of the lifespan range seems to be a frequent occurrence.

When the 12v battery gets weak, the truck begins to shed loads, and then various error messages begin to show up indication problems with a variety of the truck's systems that can be disconcerting, even though they are due to the weak 12v battery.

OTAs may fail to install and you could even end up being stranded and needing a tow.

I have the original 12v battery (flooded not AGM) in my 2012 Nissan Leaf that has been on a maintainer since about March of 2012 and still does fine - that's over 14 years. I measured the SOH (state of health) recently and it was at 80%, about the threshold for replacement. So maintainers really work.

Maybe you've already seen these, but just in case:

About putting trickle charger/maintainers on the battery and how to make it easier by adding a trickle charger wire:
https://www.f150lightningforum.com/forum/threads/charging-12v-battery.16979/

The maintainer negative should be connected downstream of the BMS sensor as shown about, or to any chassis ground - just DO NOT connect it to the actual negative battery terminal which would by-pass the BMS sensor.

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[joshtb86]

Any an all 12v lead acid batteries will last longer if on a maintainer when not in use.
The reason is sulfate build up on the plates.

If the battery is not fully charged to 100% after use, the sulfates that form as a result of the chemical process of releasing stored energy will not be driven off of the plates in the battery back into the electrolyte, and they become a permanent coating reducing the ability of the battery to deliver energy.

Over time the sulfate build-up will 'kill" the battery's ability to deliver energy.

A battery maintainer will top off the battery to 100% and avoid this problem, using a low current to avoid another potential battery issue - overheating leading to swelling, loss of electrolyte and out-gassing of hydrogen gas. That has been seen in some Lightnings as well as the early death.

If you don't use a maintainer, you might get 2-5 years out of an AGM battery depending of driving habits, etc., before needing to replace it. Maybe that's enough for some, but there are many Lightning system components that are critically dependent on the 12v battery system.

From Lightning owner reports here and elsewhere, the lower end of the lifespan range seems to be a frequent occurrence.

When the 12v battery gets weak, the truck begins to shed loads, and then various error messages begin to show up indication problems with a variety of the truck's systems that can be disconcerting, even though they are due to the weak 12v battery.

OTAs may fail to install and you could even end up being stranded and needing a tow.

I have the original 12v battery (flooded not AGM) in my 2012 Nissan Leaf that has been on a maintainer since about March of 2012 and still does fine - that's over 14 years. I measured the SOH (state of health) recently and it was at 80%, about the threshold for replacement. So maintainers really work.

Maybe you've already seen these, but just in case:

About putting trickle charger/maintainers on the battery and how to make it easier by adding a trickle charger wire:
https://www.f150lightningforum.com/forum/threads/charging-12v-battery.16979/

The maintainer negative should be connected downstream of the BMS sensor as shown about, or to any chassis ground - just DO NOT connect it to the actual negative battery terminal which would by-pass the BMS sensor.

How often driving is not enough? I typically use the car 5 or 6 days a week

I also noticed it's only at like 12.4v when the car is off via the OBD2 detector and 14.5v when car is on although it shows SOH 100% at all times

 

[chl]

How often driving is not enough? I typically use the car 5 or 6 days a week

I also noticed it's only at like 12.4v when the car is off via the OBD2 detector and 14.5v when car is on although it shows SOH 100% at all times

That's hard to say, but driving a lot will definitely help keep the LVB topped off.
5 or 6 days, but how long are your trips? At least an hour?

AGM batteries take longer to reach 100% due to their construction as explained in this post
from the Mach-e forum goes into depth about these 12v AGM batteries:

https://www.macheforum.com/site/threads/how-to-recondition-service-your-12v-battery.11069/

The car scanners will tell you what the truck thinks the SOH is, better than nothing but not 100% accurate. To really know the health of a battery it should be bench tested, at least disconnected from the vehicle, fully charged and then tested.

EDIT: tested after the fully charged battery has settled for at least 1/2 hour or more - some chemical reactions still going on for a bit of time after charging.

If you rely on the truck BMS exclusively and don't use a maintainer, and drive over an hour a day 6 days a week, you'll likely be in the high end of the 2-5 year range of lifespan.

Personally, I just like to make things last as long as possible and reduce my out of pocket expenses, so I plan on making my Lightning LVB last as long as possible by using a maintainer as an insurance policy against failure.

But to each their own.

 

[RLXXI]

How often driving is not enough? I typically use the car 5 or 6 days a week

I also noticed it's only at like 12.4v when the car is off via the OBD2 detector and 14.5v when car is on although it shows SOH 100% at all times

Don't have to drive it at all, sitting in your driveway running for an hour will charge it to 100% if it's still good.

 

[mr.Magoo]

Don't have to drive it at all, sitting in your driveway running for an hour will charge it to 100% if it's still good.

Not anymore apparently...

https://www.f150lightningforum.com/...-nightly-since-25c69-fix-17.35778/post-664658

 

[Newton]

It is counterintuitive and counter AI/ internet lore but dielectric grease should be used on both surfaces of an electrical connection. At the microscopic level a properly torqued connection will displace the grease where there is good contact and the grease will displace moisture where the contact is not so good. This protects from corrosion. Putting it on the outside of the connection does little.

Source - i deal with high amperage connections (and low voltage data) in a marine environment and have never had an issue with too much grease except on my clothes. That stuff doesn’t wash out.

 

[RLXXI]

Not anymore apparently...

https://www.f150lightningforum.com/...-nightly-since-25c69-fix-17.35778/post-664658

Yeah it still does on my truck. Apparently they changed a lot of things for the 25 year model.

1st pic is vehicle off, 2nd is running.

 

[mr.Magoo]

Yeah it still does on my truck. Apparently they changed a lot of things for the 25 year model.

1st pic is vehicle off, 2nd is running.

Yes, the DCDC is on when the truck is on, so you'll see a higher voltage compared to when it's off.

13.4V is more of a "power supply" (float) mode, and isn't used for charging.
Bulk/absorption (ie. charging) is around 14.5V for an AGM.

 

[RLXXI]

Yes, the DCDC is on when the truck is on, so you'll see a higher voltage compared to when it's off.

13.4V is more of a "power supply" (float) mode, and isn't used for charging.
Bulk/absorption (ie. charging) is around 14.5V for an AGM.

If it's not charging why does it only take an hour to get to 100% fully charged? 12.5 is a 12v battery resting voltage, anything above that IS charging. Fixing cars for a living has its advantages.

Stealing this from Google as it's quicker than typing and quite accurate according to my training.

"The nominal voltage of a 12V AGM automotive battery is 12.6V.
While labeled as "12-volt," this number represents the standard category rather than the precise charge. A fully charged AGM battery typically rests between 12.6V and 12.8V.
Key Voltage States
Fully Charged: 12.7V – 12.8V
75% Charge: ~12.4V
50% Charge (Discharged): ~12.2V
Charging Voltage: 14.4V – 14.8V (while the alternator is running)
If the battery reads exactly 12.0V, it is actually at a low state of charge (roughly 25%) and requires immediate recharging to prevent internal damage."

 

[StevenC56]

My 2024 has not been able to do the latest software update for almost 2 weeks now. I have the auto updates set for 1AM. I've driven the truck with no change and yesterday I used a maintenance battery charger on it until it showed 100% charged which was 12.6-12.7 volts by my volt meter. It still failed to update this morning. The truck's manufacture date was 5/24, so the battery isn't even 2 years old. Anything else I can try before replacing the battery?

 

[chl]

My 2024 has not been able to do the latest software update for almost 2 weeks now. I have the auto updates set for 1AM. I've driven the truck with no change and yesterday I used a maintenance battery charger on it until it showed 100% charged which was 12.6-12.7 volts by my volt meter. It still failed to update this morning. The truck's manufacture date was 5/24, so the battery isn't even 2 years old. Anything else I can try before replacing the battery?

I assume you are getting a message that the update failed, sometimes the message will say the reason is the battery, other times not.

You could try slow charging the HVB on your EVSE overnight, like at 32A, then first thing in the morning go through the update menu in the truck until you get to the update now, then follow the instructions (I think it just says to turn off the truck and close and lock the doors).

That long slow charging gives the DC-DC converter more time to charge the 12v battery.

If even that fails, I'd say call your dealership, tell them the problem and get them to check the battery AND do the update.

BTW, the maintainer has to be downstream of the BMS sensor or else the truck won't know the battery has been charged. so connect the negative as shown or to a solid chassis ground point.

 

[StevenC56]

I assume you are getting a message that the update failed, sometimes the message will say the reason is the battery, other times not.

You could try slow charging the HVB on your EVSE overnight, like at 32A, then first thing in the morning go through the update menu in the truck until you get to the update now, then follow the instructions (I think it just says to turn off the truck and close and lock the doors).

That long slow charging gives the DC-DC converter more time to charge the 12v battery.

If even that fails, I'd say call your dealership, tell them the problem and get them to check the battery AND do the update.

BTW, the maintainer has to be downstream of the BMS sensor or else the truck won't know the battery has been charged. so connect the negative as shown or to a solid chassis ground point.

Yeah, I've done all that and it still won't update. I called the Ford number on the update failed message yesterday and the lady said my battery is below 80% and I just need to go drive it 30 minutes or so. I'm going to do that today but I had it on a maintenance charger yesterday until the charger said fully charged and it still didn't update.

 

[chl]

Yeah, I've done all that and it still won't update. I called the Ford number on the update failed message yesterday and the lady said my battery is below 80% and I just need to go drive it 30 minutes or so. I'm going to do that today but I had it on a maintenance charger yesterday until the charger said fully charged and it still didn't update.

OMG they told me to drive an hour when it happened to me a few months after I got the truck and before I began using the maintainer.

If you did all that, then the battery is likely too far gone.

When they don;t get recharged back to 100% and sit there the sulfates become permanent on the plates and then the battery losses the ability to produce energy slowly but surely.

Time for a new battery most likely, unless you have some kind of 12v battery heavy load or short somewhere, but with a truck the age of yours, most likely a sulfated battery.

 

[StevenC56]

I setup an appointment with my local dealership's mobile service to replace the battery under warranty. They callwd and told me I'd have to bring my truck in and leave it for that. They said mobile service can only do recalls and service work. But they can't do the ball joint recall either so I guess only software updates. Then they tried to sell me an oil change LOL! I'm just going to buy the battery and replace it myself. We have really bad luck taking our vehicles into any dealer. Something always gets broke or damaged.

 

[StevenC56]

Anybody try a charger with a Desulfation mode to resurrect one of these factory batteries back to proper SOC range?

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