SOC loss while plugged into 120V Charger several weeks

[Adventureboy]

If your truck is plugged in for more than a few days without turning it on for any substantial period, your 12V system will still shut down many components to conserve energy. This may have affected your initial SOC reading since it may not have tracked it when things shut down. On a couple of occasions, I've seen it happen where the SOC meter climbs or drops shortly after starting to drive as it readjusts itself. It seems to be very specific to letting the truck sit for more than a couple of days. I expect the true SOC is what you set it to when you plugged in.

If you are leaving the truck for more than a day, you should put a trickle charger on the 12v battery behind the Frunk. This is an annoyance but because of the way the charge cycle is designed, 30-40 hours after your truck is charged, the 12v battery will need to shut down many systems to save the 12v battery. More than likely the module that tracks your SOC is among those that get shut down). I expect when you start up the truck after a few days, it reads the HVB voltage and takes a best guess until it fully initializes (that can read a bit higher or a bit lower than the actual HVB SOC). I say the 12v charge design is flawed - I've tracked it to many glitches like this one and I'm willing to bet lunch that if you connect the 12V trickle charger, the problem will disappear.

See my post here for the details: https://www.f150lightningforum.com/forum/threads/update-failed-12v-battery.16533/post-337593

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[FirstF150InCasco]

If your truck is plugged in for more than a few days without turning it on for any substantial period, your 12V system will still shut down many components to conserve energy. This may have affected your initial SOC reading since it may not have tracked it when things shut down. On a couple of occasions, I've seen it happen where the SOC meter climbs or drops shortly after starting to drive as it readjusts itself. It seems to be very specific to letting the truck sit for more than a couple of days. I expect the true SOC is what you set it to when you plugged in.

If you are leaving the truck for more than a day, you should put a trickle charger on the 12v battery behind the Frunk. This is an annoyance but because of the way the charge cycle is designed, 30-40 hours after your truck is charged, the 12v battery will need to shut down many systems to save the 12v battery. More than likely the module that tracks your SOC is among those that get shut down). I expect when you start up the truck after a few days, it reads the HVB voltage and takes a best guess until it fully initializes (that can read a bit higher or a bit lower than the actual HVB SOC). I say the 12v charge design is flawed - I've tracked it to many glitches like this one and I'm willing to bet lunch that if you connect the 12V trickle charger, the problem will disappear.

See my post here for the details: https://www.f150lightningforum.com/forum/threads/update-failed-12v-battery.16533/post-337593

You state, "If you are leaving the truck for more than a day, you should put a trickle charger on the 12v battery..." That seems extreme. I leave my truck for days -- sometimes weeks -- w/o doing this and -- knock on wood -- I've not had any trouble.

 

[Adventureboy]

You state, "If you are leaving the truck for more than a day, you should put a trickle charger on the 12v battery..." That seems extreme. I leave my truck for days -- sometimes weeks -- w/o doing this and -- knock on wood -- I've not had any trouble.

I agree, it seems extreme. What year and how long have you had your Lightning? Mine sat on the dealer lot for 2 months initially as we negotiated my order pricing vs. dealer pricing. I expect that may have caused some premature wear on the 12v sitting in a state of discharge for a number of weeks. I've had it for 8 months now and it always seems to be depleted in about 2 days.

I am curious to see if the SOC problem goes away for the OP if a trickle charger is used.

Lots of glitches on my side and many others on the forums ranging from messages to plug the truck in (which does nothing if the HVB is already at the target SOC) to getting service due to 12v drain, goofy SOC readings, and truck not doing what it should do because the 12v battery is excessively drained. If I drive the truck daily, no issues (maybe I should just do that).

My truck was unplugged yesterday at about noon and the 12v battery is currently at 58% 24 hours later. By this evening I will get messages in FordPass - 2 days max for me. It is exactly the same with my wife's MME although it seems she can go a day or so longer than my Lightning.

The chronic discharging of the 12v battery will lead to an early death and you'll see all kinds of goofy things on the forums caused by the untimely death of the 12v battery due to the way Ford set up the charge characteristics. I expect my 12v AGM is winding down on its usefulness and will need to be replaced under warranty soon like many others.

 

[FirstF150InCasco]

I agree, it seems extreme. What year and how long have you had your Lightning? Mine sat on the dealer lot for 2 months initially as we negotiated my order pricing vs. dealer pricing. I expect that may have caused some premature wear on the 12v sitting in a state of discharge for a number of weeks. I've had it for 8 months now and it always seems to be depleted in about 2 days.

I am curious to see if the SOC problem goes away for the OP if a trickle charger is used.

Lots of glitches on my side and many others on the forums ranging from messages to plug the truck in (which does nothing if the HVB is already at the target SOC) to getting service due to 12v drain, goofy SOC readings, and truck not doing what it should do because the 12v battery is excessively drained. If I drive the truck daily, no issues (maybe I should just do that).

My truck was unplugged yesterday at about noon and the 12v battery is currently at 58% 24 hours later. By this evening I will get messages in FordPass - 2 days max for me. It is exactly the same with my wife's MME although it seems she can go a day or so longer than my Lightning.

The chronic discharging of the 12v battery will lead to an early death and you'll see all kinds of goofy things on the forums caused by the untimely death of the 12v battery due to the way Ford set up the charge characteristics. I expect my 12v AGM is winding down on its usefulness and will need to be replaced under warranty soon like many others.

Wow, that situation stinks. Ford has GOT to fix that. (And to answer your questions, 2022 built in May 2022 Never sat on the lot as I took delivery right away. 10k miles. Lariat ER.)

 

[Maquis]

I agree, it seems extreme. What year and how long have you had your Lightning? Mine sat on the dealer lot for 2 months initially as we negotiated my order pricing vs. dealer pricing. I expect that may have caused some premature wear on the 12v sitting in a state of discharge for a number of weeks. I've had it for 8 months now and it always seems to be depleted in about 2 days.

I am curious to see if the SOC problem goes away for the OP if a trickle charger is used.

Lots of glitches on my side and many others on the forums ranging from messages to plug the truck in (which does nothing if the HVB is already at the target SOC) to getting service due to 12v drain, goofy SOC readings, and truck not doing what it should do because the 12v battery is excessively drained. If I drive the truck daily, no issues (maybe I should just do that).

My truck was unplugged yesterday at about noon and the 12v battery is currently at 58% 24 hours later. By this evening I will get messages in FordPass - 2 days max for me. It is exactly the same with my wife's MME although it seems she can go a day or so longer than my Lightning.

The chronic discharging of the 12v battery will lead to an early death and you'll see all kinds of goofy things on the forums caused by the untimely death of the 12v battery due to the way Ford set up the charge characteristics. I expect my 12v AGM is winding down on its usefulness and will need to be replaced under warranty soon like many others.

Yeah, I think your 12VB has been compromised. Mine sits for days at a time, occasionally more than a week without issues.

 

[Adventureboy]

Yeah, I think your 12VB has been compromised. Mine sits for days at a time, occasionally more than a week without issues.

I agree. It's going in for the Heated Steering add and tail light fix next week so I'll ask them to replace it. It is happening to many of us on both the Lightning and MME side. I hope Ford will fix the route cause (like charging the 12v from the HVB or EVSE when it drops below 60% instead of letting it kill itself).

In the meantime, I didn't mean to derail the post ;-). I really am curious if the trickle charger fixes Karlos' issue so we can see if it is related like mine was.

 

[Karlos]

I agree. It's going in for the Heated Steering add and tail light fix next week so I'll ask them to replace it. It is happening to many of us on both the Lightning and MME side. I hope Ford will fix the route cause (like charging the 12v from the HVB or EVSE when it drops below 60% instead of letting it kill itself).

In the meantime, I didn't mean to derail the post ;-). I really am curious if the trickle charger fixes Karlos' issue so we can see if it is related like mine was.

Thanks for the info & suggestions.

I'll fix up a quick connect to the LVB and plug it into an aircraft battery maintainer (AGM also) and see if that solves the drain problem. Probably be end of October before I have another extended idle cycle

 

[p52Ranch]

What was your initial state of change when you plugged it into the 120 outlet? Also what were the environmental conditions in the hangar? A non A/C enclosed hanger could be getting very hot inside. Perhaps the truck is cooling the battery and consuming charge. You would think the truck would charge back up to 95% but maybe it’s too hot in the hangar to charge and maintain battery temps.

 

[Karlos]

What was your initial state of change when you plugged it into the 120 outlet? Also what were the environmental conditions in the hangar? A non A/C enclosed hanger could be getting very hot inside. Perhaps the truck is cooling the battery and consuming charge. You would think the truck would charge back up to 95% but maybe it’s too hot in the hangar to charge and maintain battery temps.

SOC at start was 8%. No A/C in hanger, in Texas it's been HOT !! +100dF. I would assume that after the charging session ceased that the truck would turn off & no battery conditioning would occur & if it did for some reason, that the plugged in charger would "top it off". I've never heard the truck make any noises in the garage, so assume off is off. This is the second incident of this SOC loss, the other one was in July. Didn't see this in earlier sessions last spring where the truck sat for a week or more after charging. A session in June charged from 25-100% SOC (I thought I had set it at 90% but the truck blew right thru it). A week later it was still at 100%.

 

[p52Ranch]

SOC at start was 8%. No A/C in hanger, in Texas it's been HOT !! +100dF. I would assume that after the charging session ceased that the truck would turn off & no battery conditioning would occur & if it did for some reason, that the plugged in charger would "top it off". I've never heard the truck make any noises in the garage, so assume off is off. This is the second incident of this SOC loss, the other one was in July. Didn't see this in earlier sessions last spring where the truck sat for a week or more after charging. A session in June charged from 25-100% SOC (I thought I had set it at 90% but the truck blew right thru it). A week later it was still at 100%.

I still think that somehow the combination of 120v charging on a low SoC and high hangar temps are the cause of the problem.

The owners manual mentions 122 degrees F as the maximum temperature for charging. Perhaps that is contributing to the problem. I’ve only used 120 volt charging a few times in optimal charging conditions so I don’t have the experience you have.

 

[Karlos]

I still think that somehow the combination of 120v charging on a low SoC and high hangar temps are the cause of the problem.

The owners manual mentions 122 degrees F as the maximum temperature for charging. Perhaps that is contributing to the problem. I’ve only used 120 volt charging a few times in optimal charging conditions so I don’t have the experience you have.

Guess we'll see - IF it cools down here ! Will have another multi-week session on 13th October

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