Tracking the HVB State of Health - how much decline is normal?

If you have 20,000 miles or more, what is the SoH of your HVB?


  • Total voters
    95

mkhuffman

Well-Known Member
First Name
Mike
Joined
Nov 19, 2020
Threads
25
Messages
6,378
Reaction score
8,418
Location
Virginia
Vehicles
2021 MME GT, Jeep GC-L, VW Jetta
Country flag
When I first got my MME in November of 2021, I didn’t even consider tracking the High Voltage Battery (HVB) State of Health (SoH). But then last Fall, while tracking other data using a OBDII scanner, I noticed the SoH was much lower than the last time I noticed. I was kind of shocked with the drop.

Since then I have been mentioning this on the forum in various threads and it seems the SoH of my battery is lower than others. But it could be because I have more miles on the car. So I decided to go through all my old CarScanner data and see if I could track the SoH over time. Luckily I was able to find enough data to get a good trend.

Below the SoH is graphed relative to battery age in months as of today. The red line is the day I took delivery of the car. (Yes, it sat in Mexico for a while.)

Ford Mustang Mach-E Tracking the HVB State of Health - how much decline is normal? j2q_4LCNft_QfoEGdTmY9lIk7kFYZvSdnGr58bIc3inXL4YY14


I also compared SoH with odometer mileage. Unfortunately I was not capturing that in my CarScanner data feeds, but until the beginning of October I was using Tronity, which gives me accurate odometer readings until I had to turn it off on 10/10/22 (at 17,659 miles). I really, really miss Tronity, BTW.

Ford Mustang Mach-E Tracking the HVB State of Health - how much decline is normal? Vm7DCUQ7aTk5H9OqO1jUnR5AxJ_rXHZPBjeB4S5-lKurjjz-RQ


After Tronity ended I had to estimate the mileage based on records I recorded in my car maintenance log, which are very few. Today I added the odometer reading to the data I always capture in CarScanner, so going forward I will be able to accurately track SoH (and other data) relative to mileage. And maybe Ford will release an official API so I can turn Tronity back on again!

So many people have asked if DCFC could be causing the decline in SoH. So I went through all my charge logs, heavily leveraging Tronity until October, and compared SoH to all the DCFC battery capacity I have added since I got the car new.

Ford Mustang Mach-E Tracking the HVB State of Health - how much decline is normal? 4Z-Wj_Lh8sXpll1u6y7GfKweoQJ45xFxmSXlnvDEFsf-Z_0tJQ


I have also been asked if maybe there is a problem with the battery pack, and so I checked the HVB average voltage with the HVB module minimum voltage, and they are practically the same. Below is a graph of a 100% charge I did this morning, comparing average module voltage with minimum module voltage.

Ford Mustang Mach-E Tracking the HVB State of Health - how much decline is normal? Y8kuWXWWj-oMQcoPiNIS1e8ZH7Je9Vy3_w7fti7H8NLa4wm8mY


There have been debates in the forum regarding whether or not the SoH is accurate. I think it is. The reason I think so is because at 100% SoCD, the total energy to empty (EtE) is pretty close to what it should be per the SoH.

Ford Mustang Mach-E Tracking the HVB State of Health - how much decline is normal? qiU9QoPHZXI1jQrmQx8NX_Jqig-Fb7csDat_Aylice5L8mxrIY


For my 100% charge today, I was able to get the battery up to 83.78 kWh.

So doing the math, 83.78/91 = 92.07 %. The sensor value for SoH as of today is 91.5%. I suspect the lower SoH number is due to the fact I don’t regularly charge to 100%, so the SoH is a little off. I guess the actual SoH of the battery is what I calculated using EtE.

Another factor to consider is battery temperature. As you can see, the battery is not quite at ideal temperature but it is not cold. So I think I may get an improvement in EtE in the summer. Maybe.

Conclusion:
The SoH appears to be best correlated with mileage, and the worst correlation is with DCFC. I think if I spent the time and pulled together all charging events, instead of just the DCFC ones, we would see a strong correlation with total charging kWh. Obviously every mile that is put on the car requires a charge to get there, so that is why I think mileage correlates well. But I have a ton, literally, of charging events. And after Tronity ended, I only have FordPass as a record source, and it only goes back 30 days. Arrg.

I am very interested to see what others are getting for SoH vs. how many miles are on the car.

Update: 7/9/2023

I will continue to update this section as time progresses. Right now it looks like SoH is best correlated with DCFC, but I doubt that is really the case. As others have stated, age and the normal charging and discharging process will degrade the battery. I still think mileage will end up being the best correlation because you have to charge the car to put miles on it, and I am not tracking total kWh of charging, just DCFC kWh.

SoC has settled at 92.5% and not changed over several months.

Ford Mustang Mach-E Tracking the HVB State of Health - how much decline is normal? 1688903407329


(The red bar above is when I took delivery of the car)

Ford Mustang Mach-E Tracking the HVB State of Health - how much decline is normal? 1688903432683


Ford Mustang Mach-E Tracking the HVB State of Health - how much decline is normal? 1688903458633


Update 12/30/2023

The SoC went up to 93% for a while during the hot weather, but now has settled back down to 92.5%. As of others have said, it appears the deterioration is faster at the beginning, but then slows down as time progresses. At least that is what the data from my car shows so far.

The correlation that seemed to exist with DCFC has gone away. There now seems to be no correlation with any of the factors I am measuring. Does this mean I will stop reporting on this project? Nope! I will keep updating every few months to share with others so it may help with what to expect with your car's battery.

I am very relieved the SoH appears to have stabilized. Hopefully it won't take another turn down over the next few months.

Ford Mustang Mach-E Tracking the HVB State of Health - how much decline is normal? 1703945706204


Ford Mustang Mach-E Tracking the HVB State of Health - how much decline is normal? 1703945751520


Ford Mustang Mach-E Tracking the HVB State of Health - how much decline is normal? 1703945772010
 
Last edited:

heisnuts

Well-Known Member
First Name
Darrel
Joined
Dec 5, 2021
Threads
21
Messages
939
Reaction score
1,939
Location
Oregon
Vehicles
Model 3 Performance
Country flag
I just rolled over 20,000 miles and this is actually the first time I have looked at the state of health for the battery (97.5%). This is what it looks like after 3 HVBJB replacements and a lot of back road country driving. Maybe just like humans, exercise is really good for battery SOH.

I have the L2 home charger set to 85% and charge when it gets under 50%
I have around 10 DCFC over the entire year of ownership
I charge to 100% on weekends since I do a lot of back road driving Saturday and Sunday
Car is driven daily

Ford Mustang Mach-E Tracking the HVB State of Health - how much decline is normal? soh.PNG
 
Last edited:

dtbaker61

Well-Known Member
First Name
Dan
Joined
May 11, 2020
Threads
109
Messages
4,184
Reaction score
3,846
Location
santa fe,nm
Website
www.envirokarma.org
Vehicles
MME (delivered 2/26/21), DIY eMiata BEV
Occupation
Solar Sales/install
Country flag
you *might* find a different between SR and ER batteries, or trim levels
I have Select SR, and drive unbridled 1-p exclusively

I have 22k miles in 26months on HV.... HVBJB was replaced at 18k
...I have never used a DCFC, just Level 2
...I keep batt somewhere between 50%-80% unless I have a long day ahead and charge it 100% overnight.

checked SOH this am after charge to 100%m garage is 60F
SOH=95%
 
OP
OP
mkhuffman

mkhuffman

Well-Known Member
First Name
Mike
Joined
Nov 19, 2020
Threads
25
Messages
6,378
Reaction score
8,418
Location
Virginia
Vehicles
2021 MME GT, Jeep GC-L, VW Jetta
Country flag


breeves002

Well-Known Member
First Name
Sam
Joined
Feb 21, 2021
Threads
90
Messages
1,734
Reaction score
3,567
Location
St. Louis, MO
Vehicles
2021 Mach-E GT PE
Country flag
26k miles mine moves around some but usually 96-97% recently. Yours seems to be dropping oddly fast. I wonder if you have different behavior than me...but I'm not easy on the car and do a fair amount of DCFC, so I'm not sure.
 
OP
OP
mkhuffman

mkhuffman

Well-Known Member
First Name
Mike
Joined
Nov 19, 2020
Threads
25
Messages
6,378
Reaction score
8,418
Location
Virginia
Vehicles
2021 MME GT, Jeep GC-L, VW Jetta
Country flag
I do a lot of 1000 Amp WOTs. I wonder if that is doing it? Although @heisnuts probably has more WOTs than I do.
 

heisnuts

Well-Known Member
First Name
Darrel
Joined
Dec 5, 2021
Threads
21
Messages
939
Reaction score
1,939
Location
Oregon
Vehicles
Model 3 Performance
Country flag
I do a lot of 1000 Amp WOTs. I wonder if that is doing it? Although @heisnuts probably has more WOTs than I do.
😂 Yeah, but I do not have the GT. I would love to see the count on mine. I am sure it would easily be more than the miles when my first HVBJB went out.
 

AKgrampy

Well-Known Member
First Name
Mike
Joined
Jan 29, 2022
Threads
5
Messages
3,087
Reaction score
3,051
Location
Fairbanks, Alaska
Vehicles
Ford Expedition, Ford F-150, Mach E GT
Occupation
Retired
Country flag
Have you ever ran your battery down to a very low bevel of charge and then charged to 100%? I am not sure (no research) that would do anything with the batteries in our cars but back in the old days I know we conditioned some of our battery banks from time to time to improve their life including our 30MW storage unit.
 
OP
OP
mkhuffman

mkhuffman

Well-Known Member
First Name
Mike
Joined
Nov 19, 2020
Threads
25
Messages
6,378
Reaction score
8,418
Location
Virginia
Vehicles
2021 MME GT, Jeep GC-L, VW Jetta
Country flag
Have you ever ran your battery down to a very low bevel of charge and then charged to 100%? I am not sure (no research) that would do anything with the batteries in our cars but back in the old days I know we conditioned some of our battery banks from time to time to improve their life including our 30MW storage unit.
Yep! I followed the process @Mach-Lee specified in one of his threads for how to re calibrate the HVB. Didn't seem to change anything.
 

RickMachE

Well-Known Member
Joined
Jul 1, 2021
Threads
207
Messages
13,849
Reaction score
19,188
Location
SE MI
Vehicles
2022 Mach-E Premium 4X, 2022 Lightning Lariat ER
Country flag
I'm sure your larger loss is due to government intervention. 🤣

I peeked at ours on our trip, with around 8,000 miles and 14 months old, but only driven for 9 months (sat in Mexico), and as I recall it was 100%. I checked it when it was in Florida warmth, if that matters.
 
Last edited:

DevSecOps

Well-Known Member
First Name
Todd
Joined
Sep 22, 2021
Threads
69
Messages
4,746
Reaction score
11,537
Location
Sacramento, CA
Vehicles
'21 Audi SQ5 / '23 Rivian R1T / '23 M3P
Occupation
CISO
Country flag
I'm at 93%.

40k miles
DCFC at least 4 times a week
Charge to 100% at least twice a week

I've said this before, all the research I've read says that age+not driving the car is worse for the battery than DCFC, 100% charges and charge cycles. Of course they all wear on the battery, but your better bang for buck is to drive it, charge it, do what it's designed to do and stop worrying about it.
 
Last edited:

kennethjk

Well-Known Member
First Name
Ken
Joined
Sep 3, 2021
Threads
30
Messages
3,301
Reaction score
2,104
Location
NY
Vehicles
MME Prem. EB 4WD, X3, IX50
Occupation
Retired
Country flag
I am at 97% and 13k miles

have the car for 12 months
charge to 100% maybe 10 times
DCFC maybe 14 times

never WOT
 

RickMachE

Well-Known Member
Joined
Jul 1, 2021
Threads
207
Messages
13,849
Reaction score
19,188
Location
SE MI
Vehicles
2022 Mach-E Premium 4X, 2022 Lightning Lariat ER
Country flag
 




Top