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

[Niko]

Hello,
I just bought an OBDII and did a first test.
The Mach-E is an AWD ER 2021: 28000 Km. Bought second-hand (dealership car) at 10,000 km two years ago.
Strangely, the SOH is at 87.5%, but at 100% SOC I have an EtE of 86.75 Kwh. This should give a SOH of 95.33% based on a useful capacity of 91 Kwh.
For your information, I've had an HVJB fault and an HVJB change.
I don't understand this difference

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[mkhuffman]

Hello,
I just bought an OBDII and did a first test.
The Mach-E is an AWD ER 2021: 28000 Km. Bought second-hand (dealership car) at 10,000 km two years ago.
Strangely, the SOH is at 87.5%, but at 100% SOC I have an EtE of 86.75 Kwh. This should give a SOH of 95.33% based on a useful capacity of 91 Kwh.
For your information, I've had an HVJB fault and an HVJB change.
I don't understand this difference

You probably need to recalibrate the BMS.

@Mach-Lee wrote up a post for how to do that. I will see if I can find his post, but basically you need to charge the car to 100%, drive it down to around 10%, and then charge it back up to 100%.

I agree with you: the EtE at 100% and SoC should be pretty close. Not exactly the same, but your difference is not normal, I don't think.

 

[MACHEMIKE]

Reassuring. Thank you for the great info.

 

[Niko]

You probably need to recalibrate the BMS.

@Mach-Lee wrote up a post for how to do that. I will see if I can find his post, but basically you need to charge the car to 100%, drive it down to around 10%, and then charge it back up to 100%.

I agree with you: the EtE at 100% and SoC should be pretty close. Not exactly the same, but your difference is not normal, I don't think.

Thanks, yes I found the post, i will do the process in few days.

 

[mkhuffman]

Thanks, yes I found the post, i will do the process in few days.

For everyone else, the post is here:
https://www.macheforum.com/site/threads/hv-battery-calibration-procedure.23815/

 

[gpgrim]

25,069 miles and @95% SOH.

Batt age showing at 26.7 mos., which must be when the system controls were functional. Assembly line work was complete by 7/9/21, but was moved to a staging lot until 9/19/21 when the final chip(s) was/were installed and the bill of lading created.

Didn't load on KCS for another month and then sat in KC for another month before being dropped at the dealer in mid-Dec.

 

[Teslaeata]

25,069 miles and @95% SOH.

Batt age showing at 26.7 mos., which must be when the system controls were functional. Assembly line work was complete by 7/9/21, but was moved to a staging lot until 9/19/21 when the final chip(s) was/were installed and the bill of lading created.

Didn't load on KCS for another month and then sat in KC for another month before being dropped at the dealer in mid-Dec.

My HV SoH was around that until c65,000miles when I’d fell slightly, now at 75,000miles is around the 94% mark.

 

[mkhuffman]

I have updated the OP with the latest data from my car. Hopefully this will help people who are wondering about what to expect.

I am a new BEV owner, so this is all new to me as well. And I was not happy at all with the initial decline. Now that is appears to have stabilized, I am feeling better about the future with this car. Hopefully the SoH will remain in this general vicinity for a long time.

I will keep reporting!

 

[Mache_Nor]

I have updated the OP with the latest data from my car. Hopefully this will help people who are wondering about what to expect.

I am a new BEV owner, so this is all new to me as well. And I was not happy at all with the initial decline. Now that is appears to have stabilized, I am feeling better about the future with this car. Hopefully the SoH will remain in this general vicinity for a long time.

I will keep reporting!

Good to hear, and seems to be in line with other EVs; initially +- 5% drop the first year and then slowly degrade afterwards. My first gen Nissan Leaf (2015h with a measly 24 kwh battery is still between 85-90% after 135 000 km, and that has been regularly driven to low % and kept at 100% for hours on daily basis. If that poor thing is still somewhat functional after all this, I’m hoping that we’ll see 4-500 000 km before battery is below 80% capacity.

 

[Teslaeata]

Good to hear, and seems to be in line with other EVs; initially +- 5% drop the first year and then slowly degrade afterwards. My first gen Nissan Leaf (2015h with a measly 24 kwh battery is still between 85-90% after 135 000 km, and that has been regularly driven to low % and kept at 100% for hours on daily basis. If that poor thing is still somewhat functional after all this, I’m hoping that we’ll see 4-500 000 km before battery is below 80% capacity.

?

 

[worachj]

2023 Select AWD - MFD: 12/22.

CarScanner says my SOH is at 98.5 with 5400 miles driven at the one year anniversary of the build date. I picked up the car from the dealer on 03/10/23.

 

[mkhuffman]

I have updated this thread with the latest data from my MME. It is not a good update, as the SoH has dropped down to 88%. As I mentioned in the OP update, I am expecting (and hoping) that drop is just a BMS inconsistency and it will come back up to around where it was before.

At 100%, my last charge reached 83.85 kWH, which using math is 91% SoH.

On another note, I want to recommend everyone following this thread also follow the following thread:
https://www.macheforum.com/site/thr...-analytics-crowdsourced-data-add-yours.38065/

@flapjake314 is pulling together data from multiple vehicles in a format that is much better than the survey I did in this thread. A survey is a point in time, and there is context missing. His approach allows tracking across time and mileage with multiple entries. Great work Jake!

 

[Jepp]

I have updated this thread with the latest data from my MME. It is not a good update, as the SoH has dropped down to 88%. As I mentioned in the OP update, I am expecting (and hoping) that drop is just a BMS inconsistency and it will come back up to around where it was before.

At 100%, my last charge reached 83.85 kWH, which using math is 91% SoH.

On another note, I want to recommend everyone following this thread also follow the following thread:
https://www.macheforum.com/site/thr...-analytics-crowdsourced-data-add-yours.38065/

@flapjake314 is pulling together data from multiple vehicles in a format that is much better than the survey I did in this thread. A survey is a point in time, and there is context missing. His approach allows tracking across time and mileage with multiple entries. Great work Jake!

I’m curious. What’s your charge pattern? There’s lots of research on the NCM-battery (that’s in the ER-models) that states: Charing over 60% increases battery degradation. Staying below 60% actually halves degradation. So if you usually charge to let’s say 80% and your battery has degraded 10% in a year or two and 20 000 miles, if you had stayed below 60% for most of the time you’d only see 5% degradation.
Note: Using fast chargers and topping off to 100% from time to time for long trips is included in this number. The 60% SOC level is for week to week.

 

[mkhuffman]

I’m curious. What’s your charge pattern? There’s lots of research on the NCM-battery (that’s in the ER-models) that states: Charing over 60% increases battery degradation. Staying below 60% actually halves degradation. So if you usually charge to let’s say 80% and your battery has degraded 10% in a year or two and 20 000 miles, if you had stayed below 60% for most of the time you’d only see 5% degradation.
Note: Using fast chargers and topping off to 100% from time to time for long trips is included in this number. The 60% SOC level is for week to week.

I charge to 100% whenever I am driving out of town, which sometimes is several times a month. When not traveling, I have charged to 90% and 80%. Probably more often to 90%. I usually don't charge it again until it drops below 70%.

Many people do what I do and don't have the hit on SoC that I have experienced. I really think it is because of all the WOTs I have done. I think pulling 1000 Amps on a regular basis has to damage the battery. I didn't think about that before, and maybe I would have don't it less, but maybe not. It is one of the reasons I got the GT, so to not floor it defeats the purpose of having it.

The SoH is back up to 89%. Still not good for sure.

 

[Shayne]

I charge to 100% whenever I am driving out of town, which sometimes is several times a month. When not traveling, I have charged to 90% and 80%. Probably more often to 90%. I usually don't charge it again until it drops below 70%.

Many people do what I do and don't have the hit on SoC that I have experienced. I really think it is because of all the WOTs I have done. I think pulling 1000 Amps on a regular basis has to damage the battery. I didn't think about that before, and maybe I would have don't it less, but maybe not. It is one of the reasons I got the GT, so to not floor it defeats the purpose of having it.

The SoH is back up to 89%. Still not good for sure.

There was an article posted here lately that fast discards help the battery for degradation so who knows? Drive it like you want and see what happens. Not all CPU's are created equally and not all packs are the same. The good the bad and the ugly.

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