Low Voltage Battery low notification

[Beachbum]

I am new to this Forum. I have a 2021 Premium extended battery Mach-E with only 2600 miles on it. I keep getting the following notification "Please plug in Mach-E to recharge its battery. Its voltage is low, which could make it difficult to start your vehicle". This notification only happens when my vehicle is unused and unplugged for about 5 days. When I last got this notification the HVB was at 99% and the LVB was at 13.43 volts. Do they monitor the 12-volt battery by the length of time it is off the battery charger? Thanks for your help.

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[Billyk24]

I got the same warning driving 65 miles home from the dealership in my certified 2021 Premium trim. The hvb will charge tje 12v battery via the dc to dc inverter. My history with Ford hybrid and plug in hybrid vehicles is to use a trickle charger on a rrgular basis to avoid issues.

 

[Beachbum]

That does sound like a good idea if the battery is low, but it seems to me that I already have 13.43 volts on the battery. Will the battery maintainer do anything for my battery? Or is it just to fool the PCM? Thanks for your reply

 

[Billyk24]

That does sound like a good idea if the battery is low, but it seems to me that I already have 13.43 volts on the battery. Will the battery maintainer do anything for my battery? Or is it just to fool the PCM? Thanks for your reply

These are "float" maintainers. They monitor and charge only when "needed". The one in the photo uses less than 1 amp while charging. You may or may not benefit depending upon a variety of factors.

 

[macchiaz-o]

I've left my 2021 job 1 vehicle parked for nearly two weeks at a time, and did not experience any low voltage battery warning or FordPass notification about it.

Ford produced some battery maintenance corrections around mid-2021. They should have been installed on your vehicle if you brought it to a dealer after that time frame, as part of the glass recalls. Do you know if your dealer has done the customer satisfaction programs for your vehicle?

Without the correction, the low voltage battery wasn't being maintained while plugged in to wall power but not actively charging the high voltage pack.

 

[DevSecOps]

I got the same warning driving 65 miles home from the dealership in my certified 2021 Premium trim. The hvb will charge tje 12v battery via the dc to dc inverter. My history with Ford hybrid and plug in hybrid vehicles is to use a trickle charger on a rrgular basis to avoid issues.

Here we go again ...

@Beachbum the alert is normal and nothing to be worried about unless you have something wrong with the car. Of course that could be a possibility but the way the MachE works is that the Low Voltage Battery is maintained by the High Voltage Battery. Every time this happens, where the HVB tops off the LVB the message will appear. If, for example, you have a key fob near by and the car wakes every once in a while when you approach it the LVB will get low, and when it needs more juice it gets it from the HVB. The only time this doesn't happen is if the HVB is lower than 12% SOC.

The message you got should have been with another message at the same time. The one you mentioned is erroneous and Ford should remove it.

The reason your battery was at the correct voltage was because the car did it's job. There's nothing wrong here other than Ford sending out erroneous messages that are confusing.

As @macchiaz-o said there were vehicles from early 2021 that had issues, but most all of those have had the update to resolve this.

 

[Mari76]

The same thing has been happening to my car too. I took it to the dealership and they said there was no codes showing when they ran the diagnostics. They kept my car for almost 2 weeks trying to figure out what was wrong with it. They also said someone at Ford told them to make sure we didn't sign into other apps using the my ford account login cause that would interfere with the car system. They told me to take the car back if i continued to get the 12V faults, which I still do but the car runs fine.

 

[Billyk24]

Here we go again ... this is not what you should be doing. I am pretty sure that it was said that voltage across the LVB will prevent the car from sleeping.

@Beachbum the alert is normal and nothing to be worried about unless you have something wrong with the car. Of course that could be a possibility but the way the MachE works is that the Low Voltage Battery is maintained by the High Voltage Battery. Every time this happens, where the HVB tops off the LVB the message will appear. If, for example, you have a key fob near by and the car wakes every once in a while when you approach it the LVB will get low, and when it needs more juice it gets it from the HVB. The only time this doesn't happen is if the HVB is lower than 12% SOC.

The message you got should have been with another message at the same time. The one you mentioned is erroneous and Ford should remove it.

The reason your battery was at the correct voltage was because the car did it's job. There's nothing wrong here other than Ford sending out erroneous messages that are confusing.

As @macchiaz-o said there were vehicles from early 2021 that had issues, but most all of those have had the update to resolve this.

I can tell you the car does go into a sleep mode with the 12v trickle charger. This has been true with my three other Fords and Toyota Rav4.

 

[Beachbum]

My 2021 Mach-E was one of the last for model year 2021. It was produced in October and I bought it in November of 2021. I do believe there is no problem with my vehicle, but just getting an erroneous notification. This is the only notification I get each time. I do have a cigarette-type socket volt meter, but I think I will add access holes and caps in the frunk to measure the LVB voltage directly. I have been getting online updates regularly. I guess the next step is to contact the dealer and see if they can correct the notifications. Thanks to everyone for their input. I will update you when I visit the dealer and if anyone has any other ideas, let me know.

 

[Ford Motor Company]

I am new to this Forum. I have a 2021 Premium extended battery Mach-E with only 2600 miles on it. I keep getting the following notification "Please plug in Mach-E to recharge its battery. Its voltage is low, which could make it difficult to start your vehicle". This notification only happens when my vehicle is unused and unplugged for about 5 days. When I last got this notification the HVB was at 99% and the LVB was at 13.43 volts. Do they monitor the 12-volt battery by the length of time it is off the battery charger? Thanks for your help.

Hi there, I'd be happy to look into your Mach-E concerns on my end. Will you send us a message with your VIN and dealership info? I can look into things on my end.

 

[kodiakng]

That does sound like a good idea if the battery is low, but it seems to me that I already have 13.43 volts on the battery. Will the battery maintainer do anything for my battery? Or is it just to fool the PCM? Thanks for your reply

just checking: a full 12v LVB should read ~12.7V so are you measuring the LVB while the car is on? if so, you're measuring it while the DC-DC converter is actively charging the LVB and it will always be high. turn off the car to get an accurate reading of the LVB itself.

alternatively, if you have an OBD2 and an app (i.e. Car Scanner) you can look at the SoC the car is measuring to see if that is low.

 

[DevSecOps]

I can tell you the car does go into a sleep mode with the 12v trickle charger. This has been true with my three other Fords and Toyota Rav4.

This vehicle is nothing like your other Ford vehicles. Twice now you've advocated that people use trickle chargers when this is a very well know event with the car. 99% of the time it's nothing to worry about.

There's just absolutely no reason to put a trickle charger on an EV. You have a massive HVB that will continually top off the LVB.

People, please don't bring your car in for service for this either, unless you continuously get the message and you don't have any accessories plugged into the car. Getting this every once in a while, especially when it sits without driving it is perfectly normal. You'll just be wasting your time.

 

[Billyk24]

Tell us how this vehicle is different from my other Ford vehicles when they had a hvb, dc to dc inverter and could drive in electric mode?

 

[DevSecOps]

Tell us how this vehicle is different from my other Ford vehicles when they had a hvb, dc to dc inverter and could drive in electric mode?

My comment about it preventing the car from sleeping was something someone else said in error and I remembered that or I remembered it incorrectly. I just confirmed with Ford that it will not prevent it from sleeping. So, I stand corrected in that regard.

However, it is still nothing to worry about and I would still advise against it because if the car isn't working correctly you would want to know. Keeping a trickle on the car with a bad DC/DC inverter will only leave you stranded when you drive it. The car is well enough capable of maintaining itself. If the MME was an ICE vehicle that you garaged for weeks/months on end then I would have a different stance, but that's just not the case.

 

[Beachbum]

I will try the OBD2 method. I will not be near the vehicle for a couple of days though.

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