For those of you worried about charging to 100%...

[SnBGC]

Yep. Although there's also an argument to be made for the BMS adjusting the usable battery downward on the fly to preserve that upper buffer too. The upper buffer exists to protect the battery, and that need still exists even if it's lost 10%.

Or maybe it's some combo of both (like half out of the buffer, half out of usable)?

I really have no idea. But people doing OBD2 readings don't tend to see much loss yet on either, so we're probably good for years.

The way the folks at Magna explained it to me, the buffer doesn't need to be preserved. If a totally brand new battery has 0% deg and 4% upper buffer then it has a total of 4% that doesn't get charged. Later, as it is used and obtains 2% deg and 2% buffer then it still has that 4% in total that doesn't receive a charge. etc etc...

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[SnBGC]

Assuming each DC charging session eats up is a little bit of the max battery capacity, is charging at lower charge rate but still using Direct Current cause less degradation?
I have DCFC at 25 kwh and 50 kwh a lot more then at 150 kwh.

Yes.
To be clear.....ALL charging is Direct Current. Even L1 and L2 gets converted to Direct Current before it is presented to the HVB. Generally speaking.....we all pretty much agree that slower charging is better (all else being equal). It's always a balance between best practice mechanically and best practice for performance. As long as we have enough charge to complete the required task when needed then we are happy.

 

[ZuleMME]

Yes.
To be clear.....ALL charging is Direct Current. Even L1 and L2 gets converted to Direct Current before it is presented to the HVB. Generally speaking.....we all pretty much agree that slower charging is better (all else being equal). It's always a balance between best practice mechanically and best practice for performance. As long as we have enough charge to complete the required task when needed then we are happy.

The battery degradation from charging is called plating and occurs when the lithium ions literally plate the anode. This takes up ions that normally hold energy from moving across the membrane In the battery. This happens over time but occurs faster the:

1) Faster you charge it
2) Higher you take it

Thus the typical mantra of not using DCFC all the time and not taking it to 100% until you need it. Honestly I’ve seen some articles that indicate research that this process may be partially reversible.

 

[Dual Spool]

I'm at 98.5% - 22k miles, lots of DCFC, lots of 100% charges, 48A L2 every day, 12.2 months on battery age.

When it was new, was it a true 100%?

 

[DevSecOps]

When it was new, was it a true 100%?

Yes

 

[Southern92]

When it was new, was it a true 100%?

What process did you do to find out?

 

[RickMachE]

Honestly I don't think I could even tell if there were any degradation based on range, since it fluctuates so wildly on a regular basis. I really didn't expect any significant loss before the battery warranty runs out anyway.

This is the reality of 99.9% of EV owners. Few even know what the term means, fewer have any clue the state of their battery. At the time they sell the car, if asked they will say "no, I haven't noticed any" because it's true.

I did find one person that knew exactly, but he didn't own an EV.

 

[jeffdawgfan]

Charge to 100% every time.....usually 2-3 times a week. I use a 32a L2 charger. I have only DCFC once in 20K miles. We typically show about 300-310 miles of range in summer and around 280 miles in winter. Live in North Georgia. We had a 2018 Chevy Bolt before our MME and did the same routine. Never noticed any decrease in range on that vehicle either...before it burnt up....just kidding.

 

[MachE_DK]

Out of curiosity. Is the battery in MME worse than other EV makers since Ford has such a high buffer?
If you look at other EV they often only have 3-5 KWh buffer, much less than our beloved Mustang.
It would be awesome to have ie 94KWh capacity and not just the 88KWh in the 2021 model.

 

[RickMachE]

Out of curiosity. Is the battery in MME worse than other EV makers since Ford has such a high buffer?
If you look at other EV they often only have 3-5 KWh buffer, much less than our beloved Mustang.
It would be awesome to have ie 94KWh capacity and not just the 88KWh in the 2021 model.

The 2021s, fully updated, have 91kWh.

 

[SnBGC]

The 2021s, fully updated, have 91kWh.

My car still shows 88 kWh
It has received all dealer updates except the HVBJB recall and last OTA was 2.8.3.

 

[BadgerGreg]

Just sharing some real world usage info in case anyone wonders what they can expect down the road.
If usable range is any indication of general HVB health, then it doesn't appear that charging to 100% (displayed) has much of an effect. Of course there isn't anything wrong with choosing a lower percent for daily limits but if your driving is such that you would like to start each day at 100% then go for it. That is what I do most days and the car appears to be handling it just fine.

Wow, you’re really putting on the miles!

It’s great to see a real-world example of an EV that is not seeing any noticeable battery degradation, even halfway to 100,000 miles. This probably has something to do with Ford’s conservative approach to battery management. I can’t wait for your 100,000 mile update sometime next fall.

 

[BadgerGreg]

Coming soon.
I have already purchased a new set of tires. The tire shop by my office has them racked and labeled with my name. I am going to have them installed just before my trip to San Diego in Sept. Going to that Fully Charged Live thing....

It’s a good sign that your tires lasted this long. I assumed that the MME would burn through tires every 30,000 - 35,000 miles due to weight, but you got a very reasonable life out of them..

 

[BadgerGreg]

Dumb question. Since Ford has a ~10% buffer in the pack, will degradation eat into the buffer first, or will it affect actual usable capacity first?

@OON7 @dbsb3233 I've charged my car to 100% a few times. Rolling down the steep hill in my neighborhood, it had never decreased regen. I've always credited that to the 10% buffer.

I’m curious as to whether Ford will allow owners to unlock additional buffer when they go beyond the warranty period. This will help to offset much, if not all, of the degradation.

 

[SnBGC]

It’s a good sign that your tires lasted this long. I assumed that the MME would burn through tires every 30,000 - 35,000 miles due to weight, but you got a very reasonable life out of them..

Yes. I assumed the same. I changed my driving style a little bit and I think that made the difference.

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