Post your MG ZS EV battery SOH data please

[Johnnib]

View attachment 4512

I'm going to try to pull together some data regarding battery State Of Health, we now have cars about that have done a reasonable mileage.

These are the bits that I think would be good to know:
SOH %
Mileage done
Car age (since registered)
Rought percentage of DC (Rapid) charges vs AC charges.
How many times do you think you've charged to 100%
GOM shown in Normal(3) after a 100% charge, with both trips reset (car started without brake pedal pressed/under no load) (this gives a good indication of SOH if you haven't got access to OBD2 data)

Mine, to start things off:
SOH 97.27%
10.5k miles
7 months old
5% Rapid charging (5 Rapids done, about 100 AC charges)
About 84 charges to 100%
GOM 159miles

Are you still collecting data on battery SOH etc. I have MG5ev and access to obd

 

[Alb]

It would be better to do a dedicated MG5 Battery SOH thread.

 

[Lovemyev]

It would be better to do a dedicated MG5 Battery SOH thread.

Maybe one for each model ?.
I know @JodyS21 did a great job of keeping track of SOH etc on a spread sheet on the ZS EV Gen1 when the buggy software became a problem after some updates and BMS upgrades.

 

[Alb]

Most useful would be a thread per battery type maybe?

 

[Johnberg51]

@JodyS21

I updated my list from a former post:

First use if the car at 07-01-2020
Last 100% SoH was at 07-01-2021 @ 9000 Km

Just some value’s from the last 15 months:
12-09-2021 97,4%
01-11-2022 97,18%
01-19-2022 96,98%
?? 96,78%
03-03-2022 96,57% 15183 Km
03-14-2022 96,37% 15603 Km
04-12-2022 96,16% 16151 Km
04-30-2022 96,02%. 16666 Km
06-08-2022 95,84% 17694 Km
07-07-2022 95,82% 18205 Km
08-14-2022 95,71% 19700 Km
08-24-2022 95,40% 20391 Km
09-03-2022 94,81% 20846 Km
09-24-2022 94,67% 21380 Km
10-12-2022 94,54% 21820 Km
10-30-2022 94,42% 22194 Km
12-01-2022 94,29% 22646 Km

Everything is still quite linear going down, about 3% per year.
Still no sign of decrease of degradation.
If the degradation is going further in the same tempo it should result in
100 minus 6 x 3% = 82% SoH after the 7 years warrenty!

 

[N2STY]

Here is gen 2 LR just under 4k miles

 

[Blackeunos]

Going to collect our new ZS SR today, I've got a couple of OBD11 readers, not sure if they'll work with the ZS, but I'll give them a try.

What's the best app to read the SOH please?

 

[Lovemyev]

Here is gen 2 LR just under 4k miles View attachment 13752

After only covering 4,000 miles, I would be stocked to see it report any less to be honest.

 

[chowbenter]

I did a 100% balance charge the other day & posted it in the wrong section

It used to read 96.9% for a full charge but has now dropped down to 95.2% for a full charge.

The SOH for my 2020 ZS EV Gen 1 is down to 98.7% for a low mileage of just 2666

Full charge on normal setting with trips reset shows a range of 143 miles on the GOM in Winter.

 

[Lovemyev]

I did a 100% balance charge the other day & posted it in the wrong section

It used to read 96.9% for a full charge but has now dropped down to 95.2% for a full charge.

The SOH for my 2020 ZS EV Gen 1 is down to 98.7% for a low mileage of just 2666

Full charge on normal setting with trips reset shows a range of 143 miles on the GOM in Winter.

TBH you can get very paranoid about all of this type of stuff.
You appear to be a low mileage user so unless you are stretching the max range on a regular trip, then I would not even worry.
After a while all EV’s will start to experience some type of battery degradation, sooner or latter, it’s pure fact.
Honestly, I think you will see your figures improve when the milder conditions return.
I have bee tracking results on my Trophy LR from when we picked up the car in March 2022.
It has consistently returned a predicted range of 212 miles when charged to 80% every single time.
Over the last 7 - 10 days this figure has plummeted by 10 - 12 miles as a predicted range.
What has changed here, the very low ambient conditions.
Every thing else is identical !.
Oh …. And before anybody chips in with “It’s the heater etc etc” - it’s not, the conditions ( except the weather ) are IDENTICAL !.

 

[Zoomy]

46000km and third service
92%

 

[Kithmo]

Charged and balanced today:
5,600 miles
SOH: 99.25%
SOC: 97%
HV Voltage: 455.75V
Min cell voltage: 4.166V (MU06)
Max cell voltage: 4.231V (MU04)
Cell Imbalance: 65mV
GOM: 155 miles (without zeroing the trip)
Battery temp after charging was 11 deg C at an ambient outside temp of 8 deg C.
I have only rapid charged once in 2.5 years, the rest 7kW with a 100% charge and balance once a month.

 

[chowbenter]

Haven't used the 2020 MG ZS EV since before Xmas so as my missus is using it tomorrow & she has the heating on full blast I thought I'd do a 100% charge & balance today.
The readings are slightly different each time I charge it over the Winter months.
Mileage 2726
100% charge showing as 97% today, 100% charge showing as 95.2% a few weeks ago!!!

149 miles range in normal mode.

 

[Lovemyev]

Haven't used the 2020 MG ZS EV since before Xmas so as my missus is using it tomorrow & she has the heating on full blast I thought I'd do a 100% charge & balance today.
The readings are slightly different each time I charge it over the Winter months.
Mileage 2726
100% charge showing as 97% today, 100% charge showing as 95.2% a few weeks ago!!!

149 miles range in normal mode.

Constant shifts in ambient temperatures are largely to blame for different results.
Your indicated 455 volts show on pack, suggests that you are running on the original BMS factory software - just saying !.
You are a low mileage user and with only 2726 miles recorded, I would expect that your HV pack SOH to be very close to 100% when the ambient temperature becomes a little warmer on a constant basis.
Having a OBD device is a handy tool for keeping an eye on what is going on with your HV battery etc.
But it can make you slightly paranoid about the condition of your HV pack.

 

[chowbenter]

Constant shifts in ambient temperatures are largely to blame for different results.
Your indicated 455 volts show on pack, suggests that you are running on the original BMS factory software - just saying !.
You are a low mileage user and with only 2726 miles recorded, I would expect that your HV pack SOH to be very close to 100% when the ambient temperature becomes a little warmer on a constant basis.
Having a OBD device is a handy tool for keeping an eye on what is going on with your HV battery etc.
But it can make you slightly paranoid about the condition of your HV pack.

Yes it's been through two services now & I've asked each time will there be any software updates & always been told if it needs them it will get them, When I've picked it up I was told doesn't need any!!!! Wont charge unless the car is locked too.

 

[Lovemyev]

Yes it's been through two services now & I've asked each time will there be any software updates & always been told if it needs them it will get them, When I've picked it up I was told doesn't need any!!!! Wont charge unless the car is locked too.

TBH - If the car is running / driving and performing charging cycles without any issues, then I would not be in any great hurry to get the BMS update done !.
Unless the charging while unlocked is a “must have” or a major issue, then don’t bother !.
To obtain this feature, it required another “tick box” exercise carrying out on the MG diag computer ( usually done in conjunction with the comfort 2 update ) that easily got missed off at the time.
My previous Gen1 did get it by default.
Strangely the early Gen2 models ( like ours ) did not get this facility !.
When our current Trophy ? LR is locked and on charge, if I unlock the doors, it just keeps charging from the A/C supply.
There is a software update available to correct this issue, which I guess will get done on its first service in early March 2023.
The car will have around 10,000 miles on the clock by then !.

 

[JodyS21]

Haven't used the 2020 MG ZS EV since before Xmas so as my missus is using it tomorrow & she has the heating on full blast I thought I'd do a 100% charge & balance today.
The readings are slightly different each time I charge it over the Winter months.
Mileage 2726
100% charge showing as 97% today, 100% charge showing as 95.2% a few weeks ago!!!

149 miles range in normal mode.

SOC

Haven't used the 2020 MG ZS EV since before Xmas so as my missus is using it tomorrow & she has the heating on full blast I thought I'd do a 100% charge & balance today.
The readings are slightly different each time I charge it over the Winter months.
Mileage 2726
100% charge showing as 97% today, 100% charge showing as 95.2% a few weeks ago!!!

149 miles range in normal mode.

Real SoC at “100%” is temperature etc related - plus how balanced, so that sounds reasonable.

Your 149miles sounds wrong though. With trips reset, It should correlate with the SOH% and WLTP value.
Maybe something to do with the older software being installed.?

 

[Roldorf]

Interesting video on measuring SOH. Can you trust what the car's software tells you?

 

[JodyS21]

Interesting video on measuring SOH. Can you trust what the car's software tells you?

Interesting.
I guess the car bms supplied SOH figure could be “wrong” but it depends on how you measure it and calculate it, algorithms etc will differ between manufacturers.

I’ve done mpkwh calculations from odb2 logged trips and they don’t match exactly what the cars trip says.
The problem is all calculations are based on 3 data points - voltage, amps & distance. Distance isn’t really an issue as you only need to take it at the start and at the end of the trip.
The voltage & amps are read continuously to work out how much energy has been used(and generated), but it can only be read so many times per second depending on the device/interface/program etc. Depending on the data rate you’ll get different overall results.
One has to assume that the actual cars BMS module itself has the best access to the refreshed real-time voltage & amps, so it “should” be in the best position to measure it and keep track of totalling up the kWh that was stored in the battery.
The supplied SOC data provided by the bms would also have to be used to then calculate the full usable battery capacity - this is then used to give a SOH as a percentage of the advertised battery capacity (bit awkward for the ZS mk1 as MG don’t advertise an official usable battery capacity)

 

[chowbenter]

Real SoC at “100%” is temperature etc related - plus how balanced, so that sounds reasonable.

Your 149miles sounds wrong though. With trips reset, It should correlate with the SOH% and WLTP value.
Maybe something to do with the older software being installed.?

Yes I think you're right, Just done a full charge & balance & with trips reset shows 150 miles on normal mode.
2790 miles.