12 v battery tests good but it is going into low power mode

[Rtashiro]

Hi, I periodically go into low battery mode which doesn't allow me to command starts etc on the app. It's annoying and often I will get into the car and it will be randomly making the 2d beeps and bongs as if the 12 volt is going down. I hooked up a load tester and it is testing as a good battery. What am I missing?

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[proprepper]

Mine did that one time in the last 3 years. I think it didn't like being parked in the garage. I usually park it outside. I think it was tooo close to the keyfob all night. New 12V last year.

 

[hb.sagen]

Mine have been fine since I disabled Welcome Light. Before that it went into battery saver daily.

 

[TaxmanHog]

Cutting off Welcome Lights will help a LOT especially if your garage parking is attached to the home and the active living area is near the garage side, walking about the house with the PAAK enabled cell phone and even sitting in your easy-chair perusing the internet with the phone will trigger it.

 

[EliPNW]

This happened to me for the first time today (33K miles on the truck). Truck was plugged into the Ford Pro Charger, although was not actively charging (SOC was higher than the charge limit I had set). Overnight temps about 30F.

I recently got the software update PT-25.8.5, which includes a change to "...warning indicator light in cold temperatures." I am wondering if this update made the computer hyper sensitive to cold-ish temps, and puts the truck to sleep to "protect" it.

 

[RLXXI]

Hi, I periodically go into low battery mode which doesn't allow me to command starts etc on the app. It's annoying and often I will get into the car and it will be randomly making the 2d beeps and bongs as if the 12 volt is going down. I hooked up a load tester and it is testing as a good battery. What am I missing?

That's not a load tester, don't trust it. Get one of these instead. Schumacher BT-100 Battery Load... https://www.amazon.com/dp/B000AMBOI0?ref=ppx_pop_mob_ap_share

 

[Adventureboy]

Recommend you include the model year of your vehicles in your profile to get more precise answers

Your tester won't see a normal, age or use-related degradation in capacity until it is too late. It only does a cranking test and charging, not a capacity test.

1. How old is the 12v battery?
2. Can you clarify what you mean by periodically? Eg. I get this about once every couple of weeks, based on days with some short drives, and every day or two, when my battery got weak but still tested fine.

The 12v battery isn't as efficient in the cold, so your driving style (short drives) or keyfob/PAAK proximity will drain it faster in winter and it gets pretty cold in Winnipeg

 

[Rtashiro]

Recommend you include the model year of your vehicles in your profile to get more precise answers

Your tester won't see a normal, age or use-related degradation in capacity until it is too late. It only does a cranking test and charging, not a capacity test.

1. How old is the 12v battery?
2. Can you clarify what you mean by periodically? Eg. I get this about once every couple of weeks, based on days with some short drives, and every day or two, when my battery got weak but still tested fine.

The 12v battery isn't as efficient in the cold, so your driving style (short drives) or keyfob/PAAK proximity will drain it faster in winter and it gets pretty cold in Winnipeg

I get it every second day or so in extreme cold. Every day I’m at work and it gets left off plug all day and about once a week if it is mild weather and plugged in every night. I feel ford can do better than this. I have the truck in later this month for some minor things I’ll have them check while still on warranty. The battery is a little over 2 years old. It’s the og battery

 

[chl]

1) likely a weak battery, an ongoing issue with these trucks esp now that they are a few years old and have been mangled by the Lightning BMS over and over...btw, to really load test a battery you should disconnect it from the truck

2) it may be too late for that 12v battery, if so replace it under warranty and then keep the new on on a maintainer whenever possible to extend it's lifespan and keep the Lightning Battery Mangling System at bay.

3) if by some chance (slim) it is NOT the battery itself there have been other issues that could cause such a problem:

a short in the electrical system cause by for example a damaged 12v system cable somewhere
a bad cabin heating element
some after-market item drawing too much current when the truck is 'off'
a bad BMS sensor or some other component of that system including the DC-DC converter (although in that case the symptoms would likely be more extreme)

More likely than not, it's the 12v battery.

Get a new one under warranty then keep it on a maintainer - lots of threads about this issue.

See these links:

This post form 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/

And this one is about the different ways to charge up the battery to get OTAs:

https://www.macheforum.com/site/threads/how-to-get-failed-otas-to-install.29749/

Also several threads here about putting trickle chargers 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/

 

[Rtashiro]

has ford done anything to address this problem? seems widespread. Seems like it would be a simple software fix

 

[Adventureboy]

has ford done anything to address this problem? seems widespread. Seems like it would be a simple software fix

It is much better than it used to be. The truck does actually charge the 12v from the HVB when it gets low in most scenarios. I don't think it does it soon enough (40% SOC is too low in the winter). There are still some situations that could use some tweaking....

 

[SSNutz]

Hey, I just dropped off my 2024 Flash at the dealer today because I was seeing the same issue. Quick result - my key pad was draining the battery. .... But I did a lot of troubleshooting and tried many things mentioned here before bringing it in. This fix is covered under warranty.... So happy it was not a rodent!

 

[chl]

Hi, I periodically go into low battery mode which doesn't allow me to command starts etc on the app. It's annoying and often I will get into the car and it will be randomly making the 2d beeps and bongs as if the 12 volt is going down. I hooked up a load tester and it is testing as a good battery. What am I missing?

I just watched a lengthy video review of several battery testers, the VEEPEAK was not recommended, the Ancel was - here's a screen shot of the chart near the end of the video:

 

[chl]

Hey, I just dropped off my 2024 Flash at the dealer today because I was seeing the same issue. Quick result - my key pad was draining the battery. .... But I did a lot of troubleshooting and tried many things mentioned here before bringing it in. This fix is covered under warranty.... So happy it was not a rodent!

That's interesting - bad wiring somewhere in the keypad?

 

[chl]

It is much better than it used to be. The truck does actually charge the 12v from the HVB when it gets low in most scenarios. I don't think it does it soon enough (40% SOC is too low in the winter). There are still some situations that could use some tweaking....

I'd like to get more than 3-5 years out of mine, so hopefully, the battery maintainer will do that - worked for me on other trucks and cars, fingers crossed.

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