ZS EV SR SOH

[Aussi55]

Hi everyone,

Our 22 SR with 8k miles is now showing 94.45 % SOH.

It has only been AC charged, frequently to 100% and not left at a low or high SOC.

Now the weather is warmer I was expecting the GOM estimate to increase, however the best is 193 miles heater off and trip reset.

I have never seen it do a balance charge on any of the charge session graphs, it gets to full then stops. That being said I did notice in colder weather it would get to 100% then stay at 1.5kw which I assume was heating as that seems too high for balance. This only happened when it was very cold.

I have attached information on cell voltage etc.

Does anyone know from this if the battery is out of balance?

Could it be the firmware is in need of update?

Can anyone with a SR confirm if the SR actually does balance charge?

Just trying to figure out if something is amiss.

Many thanks in advance.

 

[N2STY]

I wouldn't worry too much the standard range appears to be on a timer for some reason for battery degradation which makes me laugh as my long-range coming up to 10,000 miles 100% SOH

 

[ashok198311]

I wouldn't worry too much the standard range appears to be on a timer for some reason for battery degradation which makes me laugh as my long-range coming up to 10,000 miles 100% SOH View attachment 17645

How do you get the SOH of battery in ZS EV..?

 

[andymgzs]

SOH.mine takes max 32kwh from 0 miles to 100%. 32/44.5 = battery knackered or lie on the battery capacity or BMS has throttled in the early update.
SOH does not tell the truth. Linear degradation is preset.

Not very good MG!

 

[N2STY]

SOH.mine takes max 32kwh from 0 miles to 100%. 32/44.5 = battery knackered or lie on the battery capacity or BMS has throttled in the early update.
SOH does not tell the truth. Linear degradation is preset.

Not very good MG!

Sounds more like a badly balanced MK1 how are reading your SOH

How do you get the SOH of battery in ZS EV..?

There are plenty of posts with the free eZS app(Android) with a compatible Bluetooth OBD2 dongle
Amazon product ASIN B08BPC179W

 

[andymgzs]

Sounds more like a badly balanced MK1 how are reading your SOH

There are plenty of posts with the free eZS app(Android) with a compatible Bluetooth OBD2 dongle
Amazon product ASIN B08BPC179W

Mg dealer did diagnostic check and I got print out.

Sounds more like a badly balanced MK1 how are reading your SOH

There are plenty of posts with the free eZS app(Android) with a compatible Bluetooth OBD2 dongle
Amazon product ASIN B08BPC179W

Mg dealer did diagnostic check and I got print out.

Sounds more like a badly balanced MK1 how are reading your SOH

There are plenty of posts with the free eZS app(Android) with a compatible Bluetooth OBD2 dongle
Amazon product ASIN B08BPC179W

Balancing takes about 4 hours every time I fully charge over night. I fast charge very rarely because I have given up doing longer distances in the MG - very poor range and no such thing as fast charge.
Fast charge was very slow. Max 36kw. Nothing like the specification and MG won’t accept there is a problem.

PS - I could buy a dongle to check it but no point - the BMS give a linear degradation curve. It’s like a software set failure after the warranty ends.

 

[N2STY]

PS - I could buy a dongle to check it but no point - the BMS give a linear degradation curve. It’s like a software set failure after the warranty ends.

The problem you have is the MK1 battery was only 44.5kw new so you say you get 32kw so that's a SOH of 88% so warranty will not apply
As for linear degradation that's only been proven on the MK2 LFP SR if you car is calling for 4 hours of balancing every charge it's suggests you have a cell down or cells what range are you getting

 

[andymgzs]

Last time I checked 32/44.5 was 72%. BTW it was the same when the car was new. Prior to a BMS update it would only take 28kwh.

I do agree with you that the battery is knackered (from new) but MG refuse to do anything because ‘no fault code’.

PICNIC.

Last time I checked 32/44.5 was 72%. BTW it was the same when the car was new. Prior to a BMS update it would only take 28kwh.

I do agree with you that the battery is knackered (from new) but MG refuse to do anything because ‘no fault code’.

PICNIC.

And 32kwh is the energy going in. Add losses in the AC to DC then it’s worse! Again a fact lost on MG.

 

[N2STY]

And 32kwh is the energy going in. Add losses in the AC to DC then it’s worse! Again a fact lost on MG.

What did MG say your SOH is on there print out? What was total voltage?
What was the max min voltage of cells?
What is your max range?
Have you tried a different dealer?
May well be worth you getting your own OBD2 so you car fight your corner with facts

 

[andymgzs]

What did MG say your SOH is on there print out? What was total voltage?
What was the max min voltage of cells?
What is your max range?
Have you tried a different dealer?
May well be worth you getting your own OBD2 so you car fight your corner with facts

Shouldn’t have to. Trying to explain to MG uk who want to ignore the problem is a waste of time. 92% SOH. I have the max voltages listed but that is meaningless to MG.
This has been going on for 2.5 years and frankly it’s a waste of time.
MG UK customer service refuse to talk on the phone and request all correspondence by email to keep it recorded. An elaborate excuse to ignore emails.
Poor experience overall. It’s a cheap car and even cheaper customer service. Would have sold it but it’s a 4 year lease.

 

[Lovemyev]

Balancing takes about 4 hours every time I fully charge over night.

If you like a good read before bed, then type BMS update in the search field and it should throw up the LONG thread on this subject on the ZS EV Gen 1 model.
We where in the first 1,000 customers for the ZS EV Gen 1 and we did have our up's and down's with software updates etc etc.
Before the car had the software cannon shot at it ( long story ) it was running on the factory software, then it had the BMS update performed.
Therefore I had about 9 - 12 months and about 8,000 miles ( ish ) running on the factory software, then the remaining 10,000+ miles and 12 months on the BMS update.
I spent WAY to long tracking the charging habits of the car after the BMS update.
So, this is what I ( and others ) had observed when it came to charging / balancing from a home wall box.
Pre and post BMS completely changed what I observed when balancing the battery at the end of a full charge cycle.
Pre BMS - When the car reached 100% SOC, the balance would commence.
The time to balance the pack was usually around the 30 minute mark.
Very rarely, it may stretch to 40 - 45 mins absolute tops !.
Post BMS - This pattern completely changed !.
After the update was done, I was told that the car would need to be fully charged and then allowed to balance for a good number of times, in order to correct any imbalance in the pack.
I however, had not suffered from the Buggy software on my car.
But some owners did have this update done, because they where experiencing problem with a sizeable loss in range after their cars became infected with a bug, that entered the car when the likes of the "Comfort 2" update was done etc.
Owners who used rapid chargers, just made the situation worse by D/C charging as higher charging rates, just made matters worse in fact !.
Post BMS - The time to complete a balance from the "get go" increased massively.
The first balance cycle had taken around 8 hours !.
Other owners reported similar times on the first cycle.
But this did quickly reduce in length, after a short time scale of a few weeks, if I remember correctly.
However, it never returned anyway close to the original 30 - 45 minutes on the factory software.
The normal time to balance after the BMS update, was about 3 - 4 hours, when it was only pulling about 500 watts to start with, then it would drop to about 300 watts and then when it hit 175 watts, it would complete very soon after hitting the 175 mark.
It is my understanding, that part of this BMS update, was to increase the buffer space at the head of the pack.
It's been suggested that this is the reason why the balance cycle time had increased post BMS update, which I am inclined to go along with.
So @andymgzs with this in mind, your car installed with the BMS update, taking about 4 hours to balance ( post BMS update ) is similar to our previous Gen 1 ZS EV then.

 

[andymgzs]

Thanks. MG told be it would take a while for the car to reach full capacity post BMS. I gave up recording the data after 12 months. Also told that if I fast charge the battery would need balancing again and it was my fault for fast charging.
For the record I fast charged about 2 times every 6 months - on the same trip out and back.
Fast charging was a joke - 36kw max ever achieved.
Never is the MG on a trip now. Waiting for lease to end.
Pretty shambolic MG.

Ps I think we were one of the early cars as well. Turned out that the car was pre-registered and the first service was due shortly after taking delivery. A 4 year lease on a secondhand car. 2 mots that I’m not looking forward to and it’s out of warranty before lease ends.
Bit of a scam!
Car had defective BMS and software on delivery - dealer and lease company would not accept that this was a fault with the car.
Problems persists - dealer has 2 month lead time for appointments - car is off the road because it keep blowing head lights. MG say it’s ok to drive!

 

[N2STY]

2 mots that I’m not looking forward to and it’s out of warranty before lease ends.

Surely not it's got 7 year warranty

 

[andymgzs]

Only on the battery. Not on the mechanics.

 

[profdraper]

Am sighty confused about this thread: it is not clear which year model he is referring to. the OP 'seems' to be referring to a MK2 facelift MY22 or beyond because he mentions 'short range' (vs long range) & not the MK1 MY21 or before where there one only one 'range' [?]

I have owned both models & am also interested in if & how the MK2 balances its battery given that there is now differnet LFP battery chemistry in this car vs NMC in the older model.

Otherwise, with my MK1 which had the latest BMS: this was always run between 20-80% & mostly form home on a 7kw wallbox. Every two months then charged to 100% and the battery balance phase always took 105mins beyond the 100% point. This never changed in the entire life of the car nor did it lose any range except for a few ks in winter.

To return to the OP, he asks "Can anyone with a SR confirm if the SR actually does balance charge?" In the case of the Mk1, this is clearly shown by the MG logo on the front of the car where it: flashes while charging; then goes solid light when balancing; then goes out when finished. In the case of the Mk2 Short Range, I have no idea & this seems to be the question being asked.

 

[andymgzs]

Mine is a 2019 Mk 1 with 44.5 kwh battery.

I do think you need to be a prof to own an MG. Really - I expect to get in and drive it. And not have to understand every BMS quirk, max volts or flashing grill.