MME has been around for 3 years, Battery lost?

[RickMachE]

Those numbers look about right and would be in line with most of the people on this forum. If they are both charged to 100% right now that would be the best time to do the math again because the car is full, and won't accept any more electrons. Then it's just a matter of seeing what is reported as energy to empty vs what a new pack is and divide the two. (i.e. 89/91).

Like I said in another post, there were a lot of people saying that the SOH was bugged in car scanner and showing 100% regardless. It didn't appear to be for everyone so maybe it was adapter based, I'm not sure (I'm using VeePeak). Doing the long hand math isn't perfect either, but it's as close as we can get. In my case, car scanner showed 93% SOH and the long hand way validated the same number.

For yucks I started charging the truck this morning before going to the dealership. Even though I gave it what I thought was enough time, it only started ramping down the charge at the end of the curve, and wasn't quite done when I had to leave.

I got up to 126.57 EtE at 99%. So maybe 128 at 100%. Of a possible 131, so 97.6%. Battery was at 71 degrees, so pretty much optimum.

Seems that if it isn't at 100% it's not accurate to do the math as was mentioned earlier.

The next time we charge to 100% for a trip with either vehicle, I will look at EtE before departing.

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[dtbaker61]

The only way to accurately measure capacity with lithium batteries is to:
- charge to full
- discharge at a moderate and steady rate (no regen), until
- near 0% SOC, and record kWhr expended

because the voltage curve of lithium is essential flat between 20%-80% you really have no idea where you are in StateOfCharge by looking at voltage until you get close to 0% or 100% 'resting voltage'. Energy measurement is thrown off by trickle current, or WOT, or regen hysterisis losses.

The difficult thing is that to be accurate you'd also have to do all this at a steady temperature.... probably on a dyno in a lab. AND you'd have had to take a baseline when new and then use the exact same procedure and conditions at a later date to get an accurate number for degradation.

All I am trying to point out is that the StateOfHealth number we see in available data is a result of a lot of aproximations to account for variables we cannot and do not control in 'regular driving'. I don't know what the margin for error is, or exactly how the SoH is determined, but I'd bet the margin for error is several percent.

 

[JohnnyForensic]

Got mine in September 2021, have 20,596 miles on it, and my battery health value is still 100%. I’ve done maybe 15 DCFC charges over that time.

 

[dbsb3233]

Minor nitpick on the title, but it's really been closer to 2 years than 3. The very first Mach-E delivery was Dec 30, 2020 IIRC. I think there were 3 delivered in those last 2 days of the year. The first real wave was Jan-2021. Those would be 2 yrs 5 mos today.

Of course, the battery cells would be months older than that, but with no miles and no significant discharge until the owner bought it with like 4 miles on the odometer.

For most of the early 2021's, it really closer to being 2 years.

 

[Haven]

I got my GT in September 2021 and have 28,000. The state of health from car scanner is 97%. I’ve done maybe 40 DCFC charges over that time. Normally charge with 32 amps in garage to 80% as I’m retired and don’t need to charge it every day. Only charge it when it gets to around 30%.

 

[BilLongua]

hey folks, wondering what kind of battery lost you are experiencing with your MME, they have been around for 3 ish years now.

I have a co worker with a 21 model Y and he has lost 21% in 2 years, with 160k (100 miles) on his, seems pretty wild

That is a lot of miles in 2 years - so is he DC fast charging a lot/majoriity of the time? I have had mine for about 18 months, with 2 winter cycles. I have noticed no drop in range. I charge at home 97% of the time on level 2. Is it also possible your friends car is just adapting to their driving habits and correcting the range accordingly?

 

[kennethjk]

15,700 miles, battery age is 17.02 and HVB SOH is 96.50

KW is 69.36 and HVB SOC is 77.63= 89.35 total available KW

 

[21st Century Pony]

I did meet a Nissan Leaf owner in late 2022 while charging... he bought his 2013 Leaf used and had about 80+k miles on the odo that evening... he said the Leaf was charging up to about 60% of spec.

Then again, I heard reliably that the earlier generation of Nissan Leafs (Leaves?) had a very aggressive battery management curve, so...

 

[Eagertrader]

My MME GT is 1.5 yrs old now. Last year in the middle of the summer the best full charge was about 287 miles. Couple of days ago, it wasn’t even that hot, about 80 degrees, and I was able to clock 302 miles of charge. If anything it seems to be getting better.

 

[ChuckA]

I may be wrong, but, if the original battery is 88 kWh and at 100,000 miles it degrades to 70 kWh, they both would show SOC 100% when fully charged. SOC is % of available capacity.

 

[RickMachE]

I may be wrong, but, if the original battery is 88 kWh and at 100,000 miles it degrades to 70 kWh, they both would show SOC 100% when fully charged. SOC is % of available capacity.

That's why SOH is what people are looking at, but it is suspect as well.

EtE (Energy to Empty) seems to be the right measure.

And all Mach-Es now have either 70 or 91kW available.

 

[bosbruce]

hey folks, wondering what kind of battery lost you are experiencing with your MME, they have been around for 3 ish years now.

I have a co worker with a 21 model Y and he has lost 21% in 2 years, with 160k (100 miles) on his, seems pretty wild

Just to be picky, first I'd like to say I expect 0 lost batteries in all Mach-Es to date.
Battery loss (%) is completely different from Battery lost !

Second, as many have stated, we don't have much data for Mach E given the short lifetimes so far.

Third, all EV manufacturers have pretty decent battery degradation warranty, and the would of course attempt to engineer their cars so that very few batteries need to be replaced within that time or mileage. Given Ford has listed >= 70% capacity by 8 years/100,000 miles, clearly mileage AND age are both factors. On top of that, of course driving and charging habits are key. Even with low mileage, if you always top the car up and keep it between 95 and 100% SOC most of the time, or use DCFC past 80% frequently, or do heavy acceleration and regen braking you could see early battery degradation. Similarly, if you store it unplugged at -40F for extended periods or leave it in completely discharged state for extended periods you will be hurting battery longevity.

For the argument of time vs. mileage, there isn't enough data on Mach E, but there is lots for Teslas that have been around long enough and most studies have focused on degradation by mileage as that seems to be a bigger factor in that one could put 300k miles a year on a car but one can only put 1 year age in a year and, based upon the 8 year warranty, it is pretty clear 1 year with no mileage (assuming reasonable storage conditions) should have very little impact on the battery health of a Mach E (or any EV).

Here's one recent study on battery degradation by mileage for Teslas for reference : https://electrek.co/2023/04/25/tesla-update-battery-degradation/

Anecdotal : a long time R/C enthusiast, ALL my batteries of various chemistry types primary factor in maintaining capacity was recharge cycles.

Tesla used to have 8 year unlimited mileage battery warranty but realized mileage had too big an impact in outlier cases so changed it to 8 years 100/120/150k miles depending upon vehicle and date of manufacture. Of course battery chemistry, packaging, cooling again may differ but here's another useful article from Tesla world on battery degradation : https://www.motortrend.com/features/how-long-does-a-tesla-battery-last/

Long and short of it : someone could easily have a Mach E GT or Tesla Performance (3/Y/Plaid) that they race hard and DCFC frequently charging to high percentages in worst case temperature conditions and have 20% loss in 1 year or 30k miles, but most people that aren't extreme in driving, charging, or storage habits will likely lose much less than 30% in 8 years or 100k miles .

 

[generaltso]

I did meet a Nissan Leaf owner in late 2022 while charging... he bought his 2013 Leaf used and had about 80+k miles on the odo that evening... he said the Leaf was charging up to about 60% of spec.

Then again, I heard reliably that the earlier generation of Nissan Leafs (Leaves?) had a very aggressive battery management curve, so...

I wouldn't base much of anything on the battery degradation seen in a Leaf since they have no active battery cooling.

 

[Mv10858]

26000 miles and 99.5%

 

[Billyk24]

lithium battery 'state of health' is super complex. It's definitely not just time, miles, or cycles. It can be affected by number of discharge events to near-zero that may zap a few out of balance cells that have less capacity than others, or number of high-current WOT events that grow dendrites, or number of times the vehicle was charged to 100% hot, and cooled to or below freezing overnight..... etc. etc. etc.

I wish I knew how the SoH number we see in OBD is calculated, but even that is an approximation since we do not drive in laboratory conditions.

The only real way to measure actual capacity of the pack is to charge to some 'near full' voltage, and measure actual energy expended to get down to some 'near empty' voltage.... all at some specific ambient temperature and output power.

Temperature control of the battery pack cells has got to be important item. Isn't 70f to 84f the preferred range? How warm does the pack get with 150kW charging?

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