So what is the best method for keeping the 12 V charged?

Peaceowl

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So far I have not found the answer to making sure the 12 V is properly charged. Mainly I am trying to understand the cars resource for the battery to remain operable. Not just when it’s parked for too long, but how is the car designed to charge it? Is it continually?

it’s been 40 years since I’ve had to have a battery checked. Did the designers of the mme lack oversite on this? I was reading in the Etron forum and they have the same dead battery/glitches in their e cars as well.

so what generates the cars 12v recharge And why isn’t it doing it’s job? Thank you for sharing your knowledge.

 

generaltso

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If you have a healthy 12V battery, you shouldn't have to do anything. The DC/DC converter charges the LVB while driving and when parked as needed. Who said it's not doing its job? Is something not working for you?
 
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Peaceowl

Peaceowl

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We’ve only had the car for a few weeks so I am unsure if anything needs charged. It appears in the forum that many times the glitches some are having leads to the discovery of a bad 12 v. I have wondered all along why this could happen to brand new cars. Noticing similar problems in other car brands as well. Simple problems like a door won’t unlock, or alarms oddly going on, etc.

i am curious why this is happening to so many cars and some finding out later it wasn’t the software causing it, but the battery.

i have to admit we have had very few problems, but knowing how long these cars sat in the sun for months in Mexico, I am wondering if many of the battery’s have cell problems to begin with.

just trying to be prepared For trouble shooting. I’ve been reading these forums for 6 months. Thanks.
 

Billyk24

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We’ve only had the car for a few weeks so I am unsure if anything needs charged. It appears in the forum that many times the glitches some are having leads to the discovery of a bad 12 v. I have wondered all along why this could happen to brand new cars. Noticing similar problems in other car brands as well. Simple problems like a door won’t unlock, or alarms oddly going on, etc.

i am curious why this is happening to so many cars and some finding out later it wasn’t the software causing it, but the battery.

i have to admit we have had very few problems, but knowing how long these cars sat in the sun for months in Mexico, I am wondering if many of the battery’s have cell problems to begin with.

just trying to be prepared For trouble shooting. I’ve been reading these forums for 6 months. Thanks.
My 2005 Escape Hybrid had this issue and I used a nightly trickle charger to get more months of use. Ford CMax Energi users also report of the same. My 2016 Toyota Hybrid does not have this issue.
 

TheVirtualTim

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The 12v battery issue was fixed much earlier this year. Here's how it works:

There is a module (which never goes to sleep) that monitors the 12v battery. When it decides the state of charge is low, it will charge it (automatically ... you don't need to do anything).

If the car IS plugged into an EVSE then it will charge off the AC power.
If the car is NOT plugged into an EVSE then it will pull power from the high-voltage battery pack.

The glitch that happened with early cars was a logic bug that failed to start charging when plugged into AC power. It has long since been fixed. No cars on the road today should have that issue.

My car had the problem in February (first month I took delivery). The Ford engineers very quickly found the bug, made a software update, and directly applied it to the car. My car has never had a 12v battery issue since. I did pick up a 12v USB adapter that reports the voltage of the outlet. If you plug it into the 12v outlet under the arm-rest and the car is off it should show the voltage coming from the 12v battery (car needs to be off). If you start the car, then it couples the high-voltage battery and that outlet will report 15v (which wont be the true state of the 12v battery ... you need to check the voltage when the high-voltage battery is de-coupled.)
 


sockmeister

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We’ve only had the car for a few weeks so I am unsure if anything needs charged. It appears in the forum that many times the glitches some are having leads to the discovery of a bad 12 v. I have wondered all along why this could happen to brand new cars. Noticing similar problems in other car brands as well. Simple problems like a door won’t unlock, or alarms oddly going on, etc.

i am curious why this is happening to so many cars and some finding out later it wasn’t the software causing it, but the battery.

i have to admit we have had very few problems, but knowing how long these cars sat in the sun for months in Mexico, I am wondering if many of the battery’s have cell problems to begin with.

just trying to be prepared For trouble shooting. I’ve been reading these forums for 6 months. Thanks.
Yeah, this was an early build problem that was fixed back in March of this year. The problem was that the 12v battery wouldn't get topped off while the HVB was charging. You shouldn't have anything to worry about there.
 

Mach-Lee

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The best method for keeping it charged is to avoid accessories that drain the battery when the car is off (like dashcams), drive the car multiple times per week, and fix any issues that come up with available software updates.

The 12V battery is charged by something called a DC/DC converter, it steps the voltage down from the big high voltage battery to charge the little 12V battery. It's like an alternator. It runs at different voltages when the car is on, when it's charging, or when it otherwise needs to.

Like Tim said, the early builds had a software issue that caused a drain, this should have been fixed with software updates or applied at the factory in all later builds.

You can check the battery voltage to make sure it's charged. It should be 12.4V or more at rest. You have to do this after the car is asleep with zero lights on however. Sometimes the batteries go bad or need extra charging to restore their capacity, but for normal use this isn't necessary. You will have lots of warnings and might not be able to drive the car if the 12V battery is actually low. A door not opening on the first press or other minor glitches are software related, not because the battery is low. It doesn't sound like you have these major issues so there's nothing you need to do currently.

Modern cars have much more going on with the charging systems than older cars, so it's much more complex. The system is optimized to use as little energy as needed to keep the 12V battery charged for efficiency.
 
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Peaceowl

Peaceowl

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Ahhh, thanx so much Tim, and everyone, great explanation. Looks like I’ve been reading way too many posts from the past?.?

I was just pondering the purchase of a volt reader for a quick check via the outlet Rather than a trickle charger. Electric cars need different tools than the ice cars! Guess it’s time to stockpile a few! ? Thnx again.

oh and thanx MachLee thanks also for the Extra Charging information link and info.

 
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