Post your MG ZS EV battery SOH data please

[JodyS21]

Hi,
My car has just had its first service at 12,000 miles/1yr and the service sheet shows the SOH is only 89%. This appears to be well below average and it is causing me some concern.
I usually charge at home to 80% or about once or twice a month to 100% and have only done about 8 DC charges in that time so I don't think that should cause such degradation.
Any thoughts on why this might be and and any actions/remedies to minimise the further losses would be most welcome.

Are you sure it’s the SOH at 89% and not the SOC.
There’s a problem if your SOH really is that at 1yr/12k.

 

[Kithmo]

My old 2020 ZS SOH was at 100% for 2.5 years before it started dropping, it went down to 98% by the time I traded it in at 3 years old. I only do 3.5K miles a year.
I charged exclusively on 7kW AC, mostly at home and Tesco's, with the exception of one time I charged from 35% SOC to 80% SOC on a rapid DC just to make sure DC charging worked.

 

[MoDolph]

Hi,
My car has just had its first service at 12,000 miles/1yr and the service sheet shows the SOH is only 89%. This appears to be well below average and it is causing me some concern.

I would suggest getting an OBD reader and confirming the measurement yourself.

Hopefully they have made a mistake and the real number is much higher.

 

[EV convert]

Thanks for all your replies and suggestions.

Unfortunately it is SOH as SOC was even lower - see pic.
I wonder if it makes a difference if the battery is warm when the test is done. It was a cold morning and I only had a couple of miles to drive (in traffic) and parked outside the dealer at 8.30 with an SOC of about 52%. When the test was done the SOC was 50% so I don't think they could have checked all the lights and heated the battery using only 3% of the charge. Any thoughts?

I will get a OBD reader but haven't used one before and have no idea how to do it or what software may/will be needed. Any suggestions to which make/model is easiest to use/best suited to the MG4 and ditto any software needed?

I will also contact the dealer to query the reading and to register the point out that, if correct, the SOH is exceptionally low for a 1 yr old car.

Thanks again.

 

[Coulomb]

I wonder if it makes a difference if the battery is warm when the test is done.

Yes. The voltage of an LFP cell in particular is very sensitive to sub-freezing temperatures. I believe that the dark blue and orange curves are supposed to be -45°C and -25°C respectively:

From https://shop.gwl.eu/blog/LiFePO4/Wh...FePO4-battery-at-low-winter-temperatures.html . The first search result for "lfp voltage versus temperature".

Edit: If I'm not mistaken, the voltage of the cell will recover when the temperature rises again, so the LFP cell isn't "inefficient" at low temperatures, it's just not releasing all of what it has stored.

 

[Coulomb]

I will get a OBD reader but haven't used one before and have no idea how to do it or what software may/will be needed. Any suggestions to which make/model is easiest to use/best suited to the MG4 and ditto any software needed?

Go for an OBD2 dongle that is a few rungs up the quality ladder, i.e. not the absolute cheapest and nastiest, but one bought through Ebay or Ali Express should be fine.

For software, a good start is the one unhelpfully called Car Scanner ELM OBD2. Though I know nothing about MG4s and their compatibility.

 

[EV convert]

Good news on my MG4 which only had 89% SOH at its first service: I raised my concerns at the dealer's service reception and after checking with the technician I was told that he had made a mistake and it should be 99% - phew! Much happier but will be getting an OBD dongle and reader/app as soon as I can figure out which one(s) will work with an EV! Any suggestions?

 

[Lovemyev]

I raised my concerns at the dealer's service reception and after checking with the technician I was told that he had made a mistake and it should be 99% - phew!

Think of a number, between 1 & 100 then halve it ............. I think I know how the rest goes .

 

[JuziWomble]

What App do people use who have APPLE devices - I like eZS - But that's Android only :-(

Thanks

 

[JuziWomble]

Good news on my MG4 which only had 89% SOH at its first service: I raised my concerns at the dealer's service reception and after checking with the technician I was told that he had made a mistake and it should be 99% - phew! Much happier but will be getting an OBD dongle and reader/app as soon as I can figure out which one(s) will work with an EV! Any suggestions?

Dont think any apps are available for the MG4 just of yet - But I might be mistaken - Lets do a search on the MG4 Thread / pages

 

[chowbenter]

Probably the last data from this excite ZS EV 2020 model, I'm thinking of upgrading to the Gen 2 Trophy model.

Just did a 100% charge & balance & the SOH has crept down from last time 97.31% to 96.85% & whatever those two software updates were when I had a service & MOT last week it still doesn't charge unless the doors are locked & it's still on 455v.
Trips reset & showing 147 miles on Normal mode in this cold weather.

 

[Lovemyev]

As you are thinking of upgrading to the Gen2 model, then I guess the latest figures on battery condition will become history soon.
As the HV voltage is still 455 volts, I think we can safely say that the car did not receive the BMS update.
Are you going for the standard range or the long range model ?.

 

[chowbenter]

I'll be going for the standard range trophy, The long range would be wasted on my low mileage usage

 

[JuziWomble]

I'll be going for the standard range trophy, The long range would be wasted on my low mileage usage

Whoever gets your LOW mileage one will get a deal ... - Ours is 3 years old with 23k - I though that was low at the time of buying it - Have since seen a few others lower ! - But not as low as yours !

Anyone suggest the best app for an iPhone user ?? Keen to have a look at ours now ...

 

[apial]

93% after 15k miles and 18 month. Charging 100% AC with 3-7,4kw

Not so happy but I still believe the software rather fakes one then calculating it accurate to keep warranty claims away - but who knows. Just 18 more month and car is gone (lease) so not to concerned about it.

 

[Lovemyev]

Manufactures tend to build a larger buffer at the head of the battery, because the initial HV battery degradation tends to higher in the first year of the batteries life cycle.
Later degradation is intended to be at a slower rate, after this initial high drop.
This process is done intensionally, to prevent owners from freaking out at early range loss.
I guess if you shrink the head space, to declare a larger usable capacity, then degradation is likely to be more noticeable earlier.
SOH readings on the ZS EV Gen1 have been widely reported on the thread on the BMS update.
@JodyS21 did some brilliant work on collecting data from many owners, it is a long thread but definitely worth a read if you have the time.
It covers cars with pre and post BMS updates.
Quick search under BMS Update should direct anybody who is interested.
As a previous owner of a ZS EV Gen1 for two years and about 20,000 miles I am convinced that battery degradation was certainly evident here.

 

[JodyS21]

Probably the last data from this excite ZS EV 2020 model, I'm thinking of upgrading to the Gen 2 Trophy model.

Just did a 100% charge & balance & the SOH has crept down from last time 97.31% to 96.85% & whatever those two software updates were when I had a service & MOT last week it still doesn't charge unless the doors are locked & it's still on 455v.
Trips reset & showing 147 miles on Normal mode in this cold weather.

Wow your mileage is so low!

Out of curiosity if you don’t mind my asking, given your very low usage, what’s the reason for upgrading at a fair cost?

 

[chowbenter]

Wow your mileage is so low!

Out of curiosity if you don’t mind my asking, given your very low usage, what’s the reason for upgrading at a fair cost?

It was my missus's choice really to change the car. We're both retired & don't use the car every day. She misses a reversing camera & most of all the heated seat which are not on this Gen 1 excite model.

 

[Lovemyev]

It was my missus's choice really to change the car. We're both retired & don't use the car every day. She misses a reversing camera & most of all the heated seat which are not on this Gen 1 excite model.

Are you going for the standard range Trophy as I don’t think heated seats are included in the SE model.

 

[chowbenter]

Are you going for the standard range Trophy as I don’t think heated seats are included in the SE model.

Yes the SR Trophy model.