Plug in to Maintain 12V Battery

[Mach1E]

OMG , now 4 in 200,000, the end of the world is nigh ????

Or the LVBs are 2+ years old and the “end of the battery is nigh.”

Seems wise to monitor it.

LVBs inevitably ALL die.

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[Mari76]

I have a '22 MME AWD ER since April ’22.

I often get a message on FordPass “Plug in to Maintain 12V Battery.”

I usually drive less than 100 miles a week, often a mile a day.

How can I keep the 12V Charged so as not to receive this message and keep my batteries healthy.

I have an Emporia home charger running at 40 AMPs.

Have you had this checked out by ford? I just took my car in for service and to also have them check why i'm getting the 12V battery fault, since Its been a while that i've been getting them. They have no clue why it's happening and they said the codes don't show up for them.

I get the fault 1-2 times a week and also the system shutdown message on the big screen but only last a couple seconds then just disappears. This has been happening the last 4 months.

 

[mkhuffman]

Have you had this checked out by ford? I just took my car in for service and to also have them check why i'm getting the 12V battery fault, since Its been a while that i've been getting them. They have no clue why it's happening and they said the codes don't show up for them.

I get the fault 1-2 times a week and also the system shutdown message on the big screen but only last a couple seconds then just disappears. This has been happening the last 4 months.

You may need to recondition your 12V battery.

 

[Mari76]

You may need to recondition your 12V battery.

how do i do that?

 

[Maquis]

how do i do that?

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

 

[Teslaeata]

Have you had this checked out by ford? I just took my car in for service and to also have them check why i'm getting the 12V battery fault, since Its been a while that i've been getting them. They have no clue why it's happening and they said the codes don't show up for them.

I get the fault 1-2 times a week and also the system shutdown message on the big screen but only last a couple seconds then just disappears. This has been happening the last 4 months.

There are 2 messages.

There’s the INFORMATIONAL message that the system is shutting down to conserve energy which means just that.

I advise you let nobody have you believe it means anything more sinister than that.

Too many incorrectly read all sorts into that message.

With respect to the other plug in to charge 12V battery message, this has been found by others to present in error.

You have it from your Ford dealer there is no fault.

The car has a perfectly good 12V battery management system.

You will do no better.

Your level of use is actually irrelevant.

All you need to do is park the vehicle with transmission in Park position with park brake applied and locked when you leave it as part of the deal.

And maintain HV battery above 15%.

At that, whether you are plugged in on charge or not, if your 12V battery reaches as low as 40% which is NOT 4.8V but is nearer 12V (because the full voltage of an AGM “12V” battery is 14+Volts and 0% is not 0V) your car will wait 48hrs before turning on the DC/DC 12V charger and start to charge your “12V” battery.

When/if 12V battery reaches 30% SoC (state oif charge, charging starts straight away.

Therefore, there’s no reason you should worry.

My advice is do not let anybody frighten you into messing about with manually charging or “reconditioning” your 12V battery which should only really be done if you are a battery expert because you can do more harm to an AGM battery than good and your battery just does not require all this I’ll-advised attention!

Don't worry and let it spoil your enjoyment of your wonderful ‘Stang.

Batteries will fail.

It’s a fact of life.

You won’t stop that happening or slow the process down.

The AGM is sealed and does not perform and lose electrolyte like the old traditional wet lead-acid batteries did.

I would just deal with its failure when/if it happens, and it may never happen.

Enjoy your ‘Stang, don’t let this subject matter spoil your life ??????????

 

[Mach1E]

There are 2 messages.

There’s the INFORMATIONAL message that the system is shutting down to conserve energy which means just that.

I advise you let nobody have you believe it means anything more sinister than that.

Too many incorrectly read all sorts into that message.

With respect to the other plug in to charge 12V battery message, this has been found by others to present in error.

You have it from your Ford dealer there is no fault.

The car has a perfectly good 12V battery management system.

You will do no better.

Your level of use is actually irrelevant.

All you need to do is park the vehicle with transmission in Park position with park brake applied and locked when you leave it as part of the deal.

And maintain HV battery above 15%.

At that, whether you are plugged in on charge or not, if your 12V battery reaches as low as 40% which is NOT 4.8V but is nearer 12V (because the full voltage of an AGM “12V” battery is 14+Volts and 0% is not 0V) your car will wait 48hrs before turning on the DC/DC 12V charger and start to charge your “12V” battery.

When/if 12V battery reaches 30% SoC (state oif charge, charging starts straight away.

Therefore, there’s no reason you should worry.

My advice is do not let anybody frighten you into messing about with manually charging or “reconditioning” your 12V battery which should only really be done if you are a battery expert because you can do more harm to an AGM battery than good and your battery just does not require all this I’ll-advised attention!

Don't worry and let it spoil your enjoyment of your wonderful ‘Stang.

Batteries will fail.

It’s a fact of life.

You won’t stop that happening or slow the process down.

The AGM is sealed and does not perform and lose electrolyte like the old traditional wet lead-acid batteries did.

I would just deal with its failure when/if it happens, and it may never happen.

Enjoy your ‘Stang, don’t let this subject matter spoil your life ??????????

Make sure to leave your ph# so when people ignore the “your battery is getting old and/or low on charge” messages they can call you for a ride when their car is stuck on the side of the road. ?

The truth lies somewhere between your “don’t worry about it” and “you should panic.”

Which, by the way, no one is saying to panic. Just to pay attention, monitor and adjust if necessary (charge or replace).

It’s a 12v battery. If you live somewhere warm, it‘s not lasting much more than 2-3 years.

 

[BMT1071]

Make sure to leave your ph# so when people ignore the “your battery is getting old and/or low on charge” messages they can call you for a ride when their car is stuck on the side of the road. ?

The truth lies somewhere between your “don’t worry about it” and “you should panic.”

Which, by the way, no one is saying to panic. Just to pay attention, monitor and adjust if necessary (charge or replace).

It’s a 12v battery. If you live somewhere warm, it‘s not lasting much more than 2-3 years.

I have not read all 9 pages of this thread, so forgive me if this has already been mentioned.
There are theories that you can perform the BMS Reset to improve charging/SOC accuracy.
https://www.macheforum.com/site/threads/priority-update-23-pu0314-dcm-lat.28818/post-657201
Regarding the 2-3 year life expectancy in warm climates, I have found that doesn't apply when the battery is not exposed to the high underhood temp ICE environment. Cars with the battery under the back seat or in the trunk fared much better. Of course we don't have engines cooking our LVB, so I would expect them to last longer.

 

[Mach1E]

I have not read all 9 pages of this thread, so forgive me if this has already been mentioned.
There are theories that you can perform the BMS Reset to improve charging/SOC accuracy.
https://www.macheforum.com/site/threads/priority-update-23-pu0314-dcm-lat.28818/post-657201
Regarding the 2-3 year life expectancy in warm climates, I have found that doesn't apply when the battery is not exposed to the high underhood temp ICE environment. Cars with the battery under the back seat or in the trunk fared much better. Of course we don't have engines cooking our LVB, so I would expect them to last longer.

Some very interesting discussions there. The BMS procedure seems like a total troll (stand on one foot and spin in a circle ?) but sure enough the battery light flashed 3x. We will see if it helps.

Also some interesting discussion about 12v state of charge and updates. I wonder if it’s why I haven’t gotten any of the recent updates in about 3 months.

 

[JamesStew71]

These “Plug in to maintain the 12v” messages had essentially stopped a while ago after software updates and a visit to the dealer. Ever since the 6.1 software update they are back with a vengeance. Anyone else seeing this correlation?

yep, never had it before. 6.1 and now we get that message. I wish ford would quit the dammed updates already. car was perfect then they jacked with havac and it uses more power than driving the dammed car

 

[Fixbear]

On the 21st I got a failed to charge and shortly after that a low battery warning, service required. Job1 select SR AWD. Dealer wanted to see it, so we took it over yesterday. They say there is a drain and can't find it yet. All this after 6.1.0 on the 16th. They have narrowed it down to 3 different units, but nothing further yet. Guess I'm not getting it back till next week sometime. And I hate the EcoSport they gave me. Damn, gas is expensive.
Any others see this happen yet?

 

[Triggerhappy007]

.

Here's another AGM chart:

Numbers are a little off, I wonder which is correct?

 

[Teslaeata]

Here's another AGM chart:

Numbers are a little off, I wonder which is correct?

Slight variation on a theme.

Both are probably correct in their respecive context.

I think first table is open voltage after a period of inactivity which is the correct way to test state of charge.

It appears second table contain values under discharge conditions at a rate of 10% of battery capacity, ie 10A for 100Ah battery.

However, today’s OBD stats for ‘Stangy show 91% SoC is 14.4V or 14.6V read at the OBD port??‍

 

[Fixbear]

That's interesting as when I was a construction equipment mechanic, we would adjust the voltage regulators to 14.6 for winter and 14.3 for summer. Batteries lasted on Caterpillar's for 7 years between overhauls. Not an easy task with the shock they go through from tracks on stones.

 

[JimmyMachE]

14.4V means the DC-DC converter was charging the 12v battery.

Both charts show open circuit /resting/ battery voltage - should be measured 12-24 hours after removing from the vehicle.

Fully charged AGM battery will reach 13V, a bit higher than normal lead acid battery.

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