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

[chl]

Yeah, here is a video of the mechanic discussing the issue

Thanks...

PS: nice to get a video like that from the service department

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[Box Cat]

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?

Your battery is probably ok with 12.65V at rest or small draw.

If you have car scanner, check the LVB quiescent average current. This gives you an indication of how much on average the truck draws from the LVB when sleeping while sporadically serving awake events for whatever causes. In my case, in normal conditions it is around 40-50 mA.
If you see a high number, that tells you the truck on average is awake more than it should.

For instance a quiescent current of around 80mA would draw almost 2Ah in a day (stock battery has 35Ah capacity), 800mA would correspond to around 20Ah, etc.

As others have indicated, you may have a faulty module or inadvertently waking up the truck by being to close with key nearby, frequent pinging with FordPass app, etc. etc.

I have not had any problems with my battery but at one point I did start seeing lower than expected battery SoC numbers and was curious why.

One way I have found to figure out what happens during the day and correlate to my movements is to monitor the battery voltage remotely with a Bluetooth sensor that constantly records the readings and which you can access with a phone app.

Nothing is connected to the truck that may keep it awake, like accessories, OBD dongle, etc., and the sensor itself, located in the closed frunk, only draws around 1-2mA.

In my case I could see that throughout the day I was waking up the truck inadvertently too often since the garage is close to living areas.

Turning off the FordPass app and not letting run in the background helped, as well as not carrying the physical key in my pocket and turning off welcome lighting.

Good luck!

 

[chl]

12.65 is about 85% I'd guess, however, you really have to wait for that voltage to 'settle' if the battery just got charged to determine what the 'resting' voltage is and whether the battery is "good."

This is a representative table:

If the voltage drops a lot after charging as the chemistry settles, then the battery is not good.

This a video demonstration of that when testing a battery based on voltage: see around minute 5:45:

 

[Timeless Epoch]

I’ve been getting the battery saver mode a lot lately too. I often only drive a few miles throughout the week, using maybe 2-4% of the battery once or twice week (more on the weeknds). One thing I recently did to help mitigate the issue is to lower my charging current to extend the charging time, giving the LVB a better chance to recuperate. Its been a bit warmer the last several days, so I am not sure yet if it helped or it is just the milder weather.

 

[chl]

I’ve been getting the battery saver mode a lot lately too. I often only drive a few miles throughout the week, using maybe 2-4% of the battery once or twice week (more on the weeknds). One thing I recently did to help mitigate the issue is to lower my charging current to extend the charging time, giving the LVB a better chance to recuperate. Its been a bit warmer the last several days, so I am not sure yet if it helped or it is just the milder weather.

Yes, that is one strategy, several others are mentioned here:

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

To maximize lifespan a maintainer is a good inexpensive option.

From all the posts, these 35AH AGM batteries are lasting up to 3 years before showing problems, warranty is 36kmiles or 3 years.

AGM batteries are supposed to last LONGER than 'wet cell' batteries. Of course they also cost more but if properly maintained should be a better value.

To last longer they need to avoid discharging below 50%, and high charging currents.

Unfortunately, the Lightnings (and Mach-e's) disobey those basics of longevity.

A low current smart charger/maintainer with an AGM mode is the way to go to maximize lifespan.

 

[davehu]

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?

happened to me multiple times. dealer replaced the battery. when the cold snap hit, it was still happening. couldn't use remote start a couple of times. many threads on the 12v battery implementation. One of the few complaints I've had with my '23.

 

[chl]

happened to me multiple times. dealer replaced the battery. when the cold snap hit, it was still happening. couldn't use remote start a couple of times. many threads on the 12v battery implementation. One of the few complaints I've had with my '23.

After reading all the posts about 12v battery failures and having an OTA that would not install about 6 months after getting my 2023 Pro, I put it on a maintainer, since then, no problemo.

 

[davehu]

After reading all the posts about 12v battery failures and having an OTA that would not install about 6 months after getting my 2023 Pro, I put it on a maintainer, since then, no problemo.

a remedy that works but is ridiculous.

 

[SSNutz]

a remedy that works but is ridiculous.

I have been charging slowly most nights, 8 amps (~1.8 kW/hr) and my 12v stay above 90% SOC. My commute to work is not enough to charge the 12v daily, so the works for me.

 

[chl]

a remedy that works but is ridiculous.

What's ridiculous is that we have to resort to such measures just to get more than 3 years or so out of the battery without doing something.

I have had great success with keeping lead-acid batteries going when on a maintainer - my 2012 Nissan Leaf flooded battery is now 13.25 years old, still starts the car...but I think I will be replacing it soon since I think I am near the outer limits of lifespan now....probably below 80% SOH.

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