The dreaded (---) on the GOM is not fun

[Cocijo]

Had my car since December 2019. Was able to do a 100 mile trip comfortably on a full charge. Today did 50 miles mainly motorway, 60 mph max. Heaters off. No other electrical loads. Used 100 miles of battery. This happened on the return journey as well. Just had the latest battery update done. The car goes in on Tuesday for a rattle problem.
Can anyone offer advice please.

Hi John,
your key metrics to look at are;
whats your HV battery voltage when fully charged and equalised? This will be either c455v or c450v (latest) depending on bms - if it’s much less then you have an issue.
on a journey check what mpk you are achieving - say you get 3mpk then 120miles on a charge should be well achievable - do this to sense check your journey/battery capacity
your predicted range should not drop significantly like you say with that type of use - this would suggest a potential bms issue - what average mpk did you get on the journey?
a couple of other things - if you regularly rapid charge that can cause the faulty bms to get much worse a lot quicker - although you say that you’ve had the latest bms update you may also need to complete a course of battery equalisations unfortunately. If your battery pack was not balanced it will take time to get back to normal - about 10hrs equalisation per 1v out of balance. I hope that this is helpful and not too confusing ?
it’s good that your car is booked in at the dealer as they should really support you if you have concerns/issues.

 

[JodyS21]

Had my car since December 2019. Was able to do a 100 mile trip comfortably on a full charge. Today did 50 miles mainly motorway, 60 mph max. Heaters off. No other electrical loads. Used 100 miles of battery. This happened on the return journey as well. Just had the latest battery update done. The car goes in on Tuesday for a rattle problem.
Can anyone offer advice please.

I think it's very important to emphasise the difference between Miles Per KwH and Range(&Volts).

If you're querying what's happened over a particular trip, the important thing to note is the Miles Per KwH in the trip computer (the journey trip automatically resets each "journey").
3.8x MpkWh is roughly what equates to the cars official WLTP range of 163 miles.
There is pretty much no quibble over this figure, it is the energy you've used with whatever type of driving you have just done.
You can divide the trips' Miles by the MpKwH, that gives you the amount of energy used up. Compare that against the supposedly full usable battery capacity of about 42.5kWh (this ignores potential regen but that's too complicated!)

If you want to check the battery capacity of the car is ok.
Fully AC charge (and balance) it.
With the car then switched on without HV battery engaged (start it without pressing the brake pedal), check the battery volts in the dash display, should either be 449/450 or 455ish dependant on the BMS software version installed.
Reset the Accumulated Trip computer. Check the (GOM) range on Normal mode / 3 KERS.

 

[ChrisR]

I think the OP said they’re still learning which is fair enough. Not everyone understands EV’s and the ins and outs of how range works.

Thanks @Cocijo. I guess I'm still learning about this forum too and was surprised to be mildly scolded for sharing an experience that I thought might be useful or interesting for others.

I was also hoping to spark some discussion about why the ZS doesn't show battery level (or even estimated range) when it is most needed. It can tell me the air pressure in my left rear tyre to the nearest 0.1 psi but chooses not to divulge the data that I really want to know.

The fact that the MG5 has a dial dedicated to battery level makes me think it is a flaw in the ZS. Perhaps MG could reallocate the 'battery' toggle to display the battery % rather than a range that has such a margin of error due to all the variables.

 

[Mark Holmes]

Thanks @Cocijo. I guess I'm still learning about this forum too and was surprised to be mildly scolded for sharing an experience that I thought might be useful or interesting for others.

I was also hoping to spark some discussion about why the ZS doesn't show battery level (or even estimated range) when it is most needed. It can tell me the air pressure in my left rear tyre to the nearest 0.1 psi but chooses not to divulge the data that I really want to know.

The fact that the MG5 has a dial dedicated to battery level makes me think it is a flaw in the ZS. Perhaps MG could reallocate the 'battery' toggle to display the battery % rather than a range that has such a margin of error due to all the variables.

I’d love to see the old Battery Toggle moved from range to battery percentage as this is more meaningful data as we know the display bar system is inaccurate in its distribution and the last bar along is equal to 25% but creates range anxiety as it looks like your nearly on empty...

“Come on MG make it happen you must be able to do this for us MG owners.....”

Let’s hope so as many have been asking for this since the Comforts 2 update...

 

[JodyS21]

I’d love to see the old Battery Toggle moved from range to battery percentage as this is more meaningful data as we know the display bar system is inaccurate in its distribution and the last bar along is equal to 25% but creates range anxiety as it looks like your nearly on empty...

“Come on MG make it happen you must be able to do this for us MG owners.....”

Let’s hope so as many have been asking for this since the Comforts 2 update...

I can't think of any other simple software improvement that could provide such a big win on the car.
If MG don't actually do it soon they are being very very silly....

 

[Cocijo]

Have we established within a reasonable level of error what each of the 8 bars on the battery level gauge actually represent in battery %? if reasonably accurate each bar would be 12.5% - how far out is it do we know? I guess that it also depends how long it has been showing on a particular bar as well. I tend to treat them as each bar is 5kwh based on 40kwh usage - this is just my rule of thumb - so if i show 5 bars and avaerage 3mpk the 25 x 3=75miles left - then check against prediction. ???

 

[JodyS21]

Have we established within a reasonable level of error what each of the 8 bars on the battery level gauge actually represent in battery %? if reasonably accurate each bar would be 12.5% - how far out is it do we know? I guess that it also depends how long it has been showing on a particular bar as well. I tend to treat them as each bar is 5kwh based on 40kwh usage - this is just my rule of thumb - so if i show 5 bars and avaerage 3mpk the 25 x 3=75miles left - then check against prediction. ???

I think someone had and it's somewhere on the forum, but I can't remember what it was.
It wasn't 100/8=12.5% per bar though.....very useful.....!

 

[jamesie]

Wasn't it 11% per graticule for the first 7 with the final being 23%?

 

[Kithmo]

Is this it ?
For the benefit of ZS EV new owners here's the state of charge as per the 8-bar gauge:

8 : 91-100%
7 : 80-91%
6 : 69-80%
5 : 58-69%
4 : 47-58%
3 : 36-47%
2 : 25-36%
1 : <25% (HV battery light comes on)

HV battery light starts flashing at 10% and will warn about aggressive driving. I believe it stops flashing and disappears at 5%.

The GoM turns to --- at 10 miles

Stick this in your phone notes for future reference.