12V Battery SOC Tips

[ZombieJester]

Hi Everyone,

2021 Job 2 EAP here.

About 4 months ago my MME was failing to do updates. After some diagnostics with the Ford team we found that my 12v was not keeping SOC at all. Put it to the dealer and they installed a new 12v. 3 or 4 updates since then have gone great. My MME was recently at repair for 2 weeks as I was backed into in my work parking lot. I have the car back and received my latest update yesterday which has failed 4 times to update. I am really hoping the 12v isn't faulty again from sitting at the repair shop.

Any tips on how I can get the 12v up to speed again? Was going to try the "leave it on for 8 hours in the driveway" tonight to see if that works. Crossing my fingers It isn't just bad luck and I have to drop it off again.

Thanks for the time and suggestions!

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[mdolan92869]

Honestly, I just bit the bullet and drilled the big holes in the cover following the template provided here (https://www.macheforum.com/site/thr...cess-battery-access.10976/page-10#post-592027) and got the plastic caps.

After reading that there's an update ready, I put the charger I have on the battery before I head out for lunch today. Should be good to go. No idea if it really needed it, but last week I got the 12V battery alert on the dash and plugged it in after I got back home.

Hiding the battery like that is a really bad idea.

 

[RickMachE]

Hi Everyone,

2021 Job 2 EAP here.

About 4 months ago my MME was failing to do updates. After some diagnostics with the Ford team we found that my 12v was not keeping SOC at all. Put it to the dealer and they installed a new 12v. 3 or 4 updates since then have gone great. My MME was recently at repair for 2 weeks as I was backed into in my work parking lot. I have the car back and received my latest update yesterday which has failed 4 times to update. I am really hoping the 12v isn't faulty again from sitting at the repair shop.

Any tips on how I can get the 12v up to speed again? Was going to try the "leave it on for 8 hours in the driveway" tonight to see if that works. Crossing my fingers It isn't just bad luck and I have to drop it off again.

Thanks for the time and suggestions!

It takes like 15-20 minutes for the battery to top off while running, so 8 hours is excessive.

You are not alone in recent updates failing. If you are driving it, it's getting charged, so you need do nothing special.

 

[ZombieJester]

It takes like 15-20 minutes for the battery to top off while running, so 8 hours is excessive.

You are not alone in recent updates failing. If you are driving it, it's getting charged, so you need do nothing special.

Thanks for the clarification. On the OTA forum someone said I am at 85% SOC and the update probably needs 90+ to install so to let it run when I get home. Pretty silly but just glad I might not have to drop the car off again.

 

[Mach-Lee]

It takes like 15-20 minutes for the battery to top off while running, so 8 hours is excessive.

You are not alone in recent updates failing. If you are driving it, it's getting charged, so you need do nothing special.

I'm going to interject here, it actually can take a very LONG time to get to high SoC. It charges quickly at first, but the last 10-20% is very slow.

Looking at my history, on a recent test it took 35 minutes to go from 80% to 90% SoC. Above 90% it gets really slow, like it could take another hour or two to reach 100% from 90%.

The problem is a lot of these OTA updates want very high SoCs, and because of the kinetics of lead acid charging it takes a long time to get the battery that high.

I told him to try leaving it on for a couple hours, that does work for some people that can't put a 12V charger on it.

 

[RickMachE]

I'm going to interject here, it actually can take a very LONG time to get to high SoC. It charges quickly at first, but the last 10-20% is very slow.

Looking at my history, on a recent test it took 35 minutes to go from 80% to 90% SoC. Above 90% it gets really slow, like it could take another hour or two to reach 100% from 90%.

The problem is a lot of these OTA updates want very high SoCs, and because of the kinetics of lead acid charging it takes a long time to get the battery that high.

I told him to try leaving it on for a couple hours, that does work for some people that can't put a 12V charger on it.

Interesting.

When I had an update not applying recently, I let it run until it got to 81 or 82%, and then it applied just fine.

 

[Mach-Lee]

Interesting.

When I had an update not applying recently, I let it run until it got to 81 or 82%, and then it applied just fine.

Yeah the thresholds vary depending on the OTA and your battery capacity. Sometimes 80% is fine, other times it has to be >95%. It basically calculates if the battery will go dead while applying the update, if it thinks it will, then it won't install.

 

[ZombieJester]

Yeah the thresholds vary depending on the OTA and your battery capacity. Sometimes 80% is fine, other times it has to be >95%. It basically calculates if the battery will go dead while applying the update, if it thinks it will, then it won't install.

This is all great stuff as I am not very smart when it comes to car stuff outside of the standard tech. Looks like I need to look into getting CarScanner and one of the dongles so I can check my SOC.

 

[Mark Hassa]

To solve a recent failed update, all I did was drive to do some errands, and while I was there, I left the car running. I did my rounds and drove home. Total time was about 1.5 hours. Once home I ran the update again and it took.

 

[ZombieJester]

To solve a recent failed update, all I did was drive to do some errands, and while I was there, I left the car running. I did my rounds and drove home. Total time was about 1.5 hours. Once home I ran the update again and it took.

I have about a 25 mile drive home and then will be at the gym so I will leave it running while there and see what happens.

 

[Mach-Lee]

To help illustrate how long it takes for the 12V to charge, I pulled some data from a previous charge/discharge test:

As you can see, the rate of charge is non linear, slowing down quite a bit at the top end. As a result, charging to 95% can take up 4 hours depending how low the battery was to start with.

 

[Bayviews88]

I love it when MachE owners come together to address these kinds of intricate issues befalling our vehicles. (Thanks @MachLee) Yet this points out a continuing issue, that for those who don’t have an early adopter mindset or skills it is a challenge to maintain a first generation EV.

Hopefully this is resolved for MY22 and beyond - I did get an alert in FordPass that my 12V in my MY22CR1 was low and I should plug in my car presumably to increase the SoC [I had been using my car lightly for short trips without plugging in that week] - but if this isn’t addressed Ford will alienate a future generation of EV owners with a poor experience in keeping their vehicles up to date.

 

[ZombieJester]

Update:
I let the car run for 5 hours just to see if it would hit the SOC. Tried to run the update and it still failed. It's set to try again at 1am so let's see. Car is off, locked and lights set to auto. Unfortunately I do not have the option to charge at home (stupid HOA). What a pain in the ass...

 

[em5quare]

To help illustrate how long it takes for the 12V to charge, I pulled some data from a previous charge/discharge test:

As you can see, the rate of charge is non linear, slowing down quite a bit at the top end. As a result, charging to 95% can take up 4 hours depending how low the battery was to start with.

How long do you think it would take if you plug the car in instead of driving around?

 

[Mach-Lee]

Update:
I let the car run for 5 hours just to see if it would hit the SOC. Tried to run the update and it still failed. It's set to try again at 1am so let's see. Car is off, locked and lights set to auto. Unfortunately I do not have the option to charge at home (stupid HOA). What a pain in the ass...

Well after 5 hours you got it up to 95% but it still didn't want to install. Suggested next steps are an external battery charger, or disconnecting the negative battery terminal to do a 12V reset.

How long do you think it would take if you plug the car in instead of driving around?

You'd want to make sure the car charges for at lest 6 hours, e.g. 50% to 100%. Having it plugged in without charging does not help.

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