Is there a software update I can get to improve the range?

[Gomev]

What is GOM?

Guess-O-Meter - miles range left.

 

[John Arnold]

Hi Folks,
I beg to differ about the quality of the GOM in the ZS EV.
In my opinion it is one of the best on the market. This is the opinion also of several professional reviewers including B Nyland from Norway.
The ZS EV GOM does exactly what it is designed to do.
I will recommend to all those who feel their GOM is not working right to have it checked.
As for this simple multiplication that is persistently being pushed down our throats please forget it. The Current and Acummulated data does work on averages but the GOM is more complicated than that.
These are the official MG data:
View attachment 604

Had a response from the Dealership. They say another BMS update, previous update done 3 weeks ago, is being applied. This will require 325 hours of either driving or charging. I have asked which one. If driving this would take me a year to achieve. If charging with my limited range and using the Granny Charger this could be achieved in about 8-10 weeks.
All without any guarantee of a full resolution. All this leaves me very unsure whether to cut and run or not.

 

[Mike]

Had a response from the Dealership. They say another BMS update, previous update done 3 weeks ago, is being applied. This will require 325 hours of either driving or charging. I have asked which one. If driving this would take me a year to achieve. If charging with my limited range and using the Granny Charger this could be achieved in about 8-10 weeks.
All without any guarantee of a full resolution. All this leaves me very unsure whether to cut and run or not.

What is your voltage when fully charged to 100%?

 

[Cocijo]

Had a response from the Dealership. They say another BMS update, previous update done 3 weeks ago, is being applied. This will require 325 hours of either driving or charging. I have asked which one. If driving this would take me a year to achieve. If charging with my limited range and using the Granny Charger this could be achieved in about 8-10 weeks.
All without any guarantee of a full resolution. All this leaves me very unsure whether to cut and run or not.

There’s lot of responses on here about equalization and bms updates. If you are struggling, I would strongly suggest that you firmly push back to the dealer and tell them to sort it out. From what you say you can no longer use the car as intended due to significant loss of range. Tell them you are not prepared to accept the car in its current condition. That is not being unreasonable - it’s unacceptable to be expected to sort it out yourself and during that time suck up the consequences.

 

[RossN]

GOM is an acronym for Guess O Meter...i.e. the amount of miles the car says it will go...it varies so much thats why we call it a GOM

 

[John Arnold]

What is your voltage when fully charged to 100%?

Full charge on eco 165 , 175 with heating control turned off.

 

[John Arnold]

Full charge on eco 165 , 175 with heating control turned off.

Sorry I thought you meant mileage. Voltage 435

 

[rbpasapera]

Sorry I thought you meant mileage. Voltage 435

I think your car was affected by the duff BMS, with the latest BMS update your car needs to recover from the old BMS, it will take a little time to recover.

 

[John Arnold]

Yes I think you’re right. The dealer said 325 hours of battery charging would be required. Is that what you have heard?

 

[JodyS21]

Yes I think you’re right. The dealer said 325 hours of battery charging would be required. Is that what you have heard?

lol you've posted this on 3 different posts! And had the question answered several times!

There's tons on here about the bad BMS and what to do.

The dealer should have told you when they took the car in to fix (and apply the fixed BMS), that it would take many hours of AC charging to get the battery back to full use. I personally if the dealer didn't tell you any of this originally when you took it in because of the issue, not use that dealer again.

435Volts is 15 out of full (450v), guess 10 hours AC charging (actually balancing) per 1V out, so 150 odd hours needed.
In my opinion you are within your right to make the dealer keep the car and sort it out under their time and costs.

 

[Cocijo]

Completely agree

 

[Chrispydoc]

Guess O Meter.......your predicted range......based on historical trips etc.

Ive had by car 15 months and done about 8k miles.

Ive always found mine pretty accurate.

Currently with everything switched off and in eco mode, mine in predicting 172 miles.
(But it is in a heated garage....so it doesn't know its minus 1out there ! ..)

 

[123]

.

 

[Dr Dave]

There’s lot of responses on here about equalization and bms updates. If you are struggling, I would strongly suggest that you firmly push back to the dealer and tell them to sort it out. From what you say you can no longer use the car as intended due to significant loss of range. Tell them you are not prepared to accept the car in its current condition. That is not being unreasonable - it’s unacceptable to be expected to sort it out yourself and during that time suck up the consequences.

Take the car to the dealer to sort out. Read the attachment, it states 'the option should be offered to the customer for them to leave the vehicle for continuous charging at the dealership'

 

[Cocijo]

Reading those notes is interesting - thank you. I thought cell balancing only occurred after a full charge. It seems that if the car is left standing in ready mode the cells also balance and that this is how dealers are told to balance cells. Also each 0.001v imbalance takes 1hr - so 1000hrs to get 1 volt?
That said it doesn’t change much as far as getting the car sorted - if it is that John genuinely wants to sort the car and not just repeat posts on various threads getting the same responses - then get it back to the dealer for them to sort it out. If of course he has had enough of the car that’s another matter and it may be time to move on. Either way continually asking the same questions won’t get the car sorted.

 

[Gomev]

Very interesting that just leaving the car in Ready mode after fully charging does the balancing as well.
Not many people knew that

 

[Dr Dave]

Take the car to the dealer to sort out. Read the attachment, it states 'the option should be offered to the customer for them to leave the vehicle for continuous charging at the dealership'

Very interesting that just leaving the car in Ready mode after fully charging does the balancing as well.
Not many people knew that

The MG ZS cell balancing process dealer information sheet I attached to my earlier post does not instill me with confidence in MG. They contradict themselves ie. '6 If the average is above 100mV and below 450mV' and in '7 If the average is above 450mV... until the cell balance is below 100mV.

In the example table they seem to mix up volts and millivolts.

The table refers to Average mV of
0.137 when they mean 0.137 Volts.

Do MG really know what they are doing?

 

[Cocijo]

That’s debatable... I’m confused on this mV thing. A mV is one thousandth of a volt correct? Some owners have their cars voltage over 10v out of balance. MG say 10hrs balancing per mV - so for 10v to make up that’s 10,000 hors balancing. Where have I gone wrong?

 

[JodyS21]

Take the car to the dealer to sort out. Read the attachment, it states 'the option should be offered to the customer for them to leave the vehicle for continuous charging at the dealership'

That's great info to get a copy of that.

I wonder if @Stuart Wright could create a permanent post to which any official copies of letters such as this can be added to, to keep them all in one place?

 

[JodyS21]

Very interesting that just leaving the car in Ready mode after fully charging does the balancing as well.
Not many people knew that

I wonder if @MilesperkWh could comment on this - this is the first time it has ever been mentioned that just leaving a car in Ready mode will rebalance the battery cell packs.

Obviously it is possible that it could do this, but I'd be surprised to be honest; as being in ready mode assumes the car is to be used and therefore you wouldn't expect the charging balancing process to run.

Reading those notes is interesting - thank you. I thought cell balancing only occurred after a full charge. It seems that if the car is left standing in ready mode the cells also balance and that this is how dealers are told to balance cells. Also each 0.001v imbalance takes 1hr - so 1000hrs to get 1 volt?
That said it doesn’t change much as far as getting the car sorted - if it is that John genuinely wants to sort the car and not just repeat posts on various threads getting the same responses - then get it back to the dealer for them to sort it out. If of course he has had enough of the car that’s another matter and it may be time to move on. Either way continually asking the same questions won’t get the car sorted.

I was thinking the 1mV per hour, relates to each cell. So each of the cells within the 9 cell packs can have their min/max moved by 1mV per hour.
Remember there are 12 cells in each pack (12*9=108*4.2v=453.6)
So in theory you could move a maximum total of 108mV (0.108V) per hour.

In terms of the total voltage shown in the car, I believe it charges until the first cell reports it has hit "max" voltage, then it stops and kicks in balancing.
So it could potentially be one cell causing the charge to stop "early", so just fixing this worst one cell could kind of suddenly free up the others to be charged higher and then give a higher total voltage.