MG4 Restricted speed - weird

[Thorpey]

If you have a charger that can show you how much charge is put into the battery you could also use the starting percentage and calculate if it is fully charging.

 

[Ayoull]

If you have a charger that can show you how much charge is put into the battery you could also use the starting percentage and calculate if it is fully charging.

That doesn't account for the balancing or loses during charging as I can put upto 48kWh into our 44.5kWh ZS EV MK1 due to those

 

[Thorpey]

That doesn't account for the balancing or loses during charging as I can put upto 48kWh into our 44.5kWh ZS EV MK1 due to those

It does if you assume the charger is 90% efficient. I'm expecting it to be several kWh out if a problem is showing at 40% charge

 

[Ayoull]

It does if you assume the charger is 90% efficient. I'm expecting it to be several kWh out if a problem is showing at 40% charge

Balancing can use between 0.2 and 2.0kWh from experience depending on how far out of balance the cells are, the only way to be 100% sure it is balanced is to either have a smart charger where you can see a current or kWh chart or leave it on charge for a atleast 3-4hrs after reaching 100%

 

[bowfer]

Balancing can use between 0.2 and 2.0kWh from experience depending on how far out of balance the cells are, the only way to be 100% sure it is balanced is to either have a smart charger where you can see a current or kWh chart or leave it on charge for a atleast 3-4hrs after reaching 100%

Willing to give that a go.
I’m emailing the dealer tomorrow to record the incident again though, and give them more detail that it appears to happen around 40% charge.

 

[Thorpey]

Balancing can use between 0.2 and 2.0kWh from experience depending on how far out of balance the cells are, the only way to be 100% sure it is balanced is to either have a smart charger where you can see a current or kWh chart or leave it on charge for a atleast 3-4hrs after reaching 100%

I'm expecting the car to stop charging far earlier than the theoretical battery capacity as it isn't fully balancing. Balancing is still charging it just is only on selected cells so the total amount of charge accounting for the 10% loss will be less than the expected amount taking current percentage and maximum capacity of the battery.

 

[bowfer]

@Michael1982
I’ll be really interested to see if your dealer can ‘see’ the incidents you’ve suffered.
As that will obviously mean they can see mine too.
If they can see the incidents I’m beginning rejection too.
I’m over 30 days too but a good 7 or so of those have been using loan cars while mine was in their workshop.
TBH I’ll take a small financial hit for ‘fair use’ just to get rid of this car.
Let me know what your dealer says ASAP?

 

[M101]

So after a lovely 3 hour wait at MG today they found a couple of registered faults and did a full system reset and then 5 software updates.
The car was fine all the way home and achieved 2.7m/kwh over 8 miles which is an improvement and that was in a lot of stop/start traffic so I don't know if that helps or makes things worse

Tomorrow's commute will be a better test but I'll let you know if it's improved

 

[Cocijo]

I don’t have MG4 experience, but I’ve experienced restricted power on cars with imbalanced HV packs before.
It usually occurs when the HV pack is at at the lower end of charge and the bms is looking to protect cells that are out of balance. I know that on some early ZS EV’s there was a bms issue that caused imbalanced cells.
The dealer should be able to read each cell and advise on state of balance as well as health. Usually a full AC charge and balance helps (sometimes a few of these are needed).
Of course your issue could be something completely different. Frustrating though.

 

[bowfer]

does it have anything to do with improving excessive battery drainage or withholding power with lots of battery left?
I had another miserable drive to work today, i had 49% battery when i set off, there was no power, the car refused to accelerate and it put me in a very dangerous position when i joined the bypass and would not accelerate, the car crawled to 40 mph while i had approaching vehicles. I arrived at work after 9 miles of driving with only 32% battery and 32 miles of range.
Its going back to MG next week and i want one of 3 things, Fix it, swap it for one that works or give me a full refund and let it be someone else's problem and potential death trap!.

So after a lovely 3 hour wait at MG today they found a couple of registered faults and did a full system reset and then 5 software updates.
The car was fine all the way home and achieved 2.7m/kwh over 8 miles which is an improvement and that was in a lot of stop/start traffic so I don't know if that helps or makes things worse

Tomorrow's commute will be a better test but I'll let you know if it's improved

Did they think this was connected to the restricted speed??
Be brilliant if some of the fault codes were very specific to restricting speed.

 

[Ian Key]

So after a lovely 3 hour wait at MG today they found a couple of registered faults and did a full system reset and then 5 software updates.
The car was fine all the way home and achieved 2.7m/kwh over 8 miles which is an improvement and that was in a lot of stop/start traffic so I don't know if that helps or makes things worse

Tomorrow's commute will be a better test but I'll let you know if it's improved

Keeping fingers crossed for you

 

[M101]

Did they think this was connected to the restricted speed??
Be brilliant if some of the fault codes were very specific to restricting speed.

They said because 1 fault was charging related that it could have been triggering a low power mode
Time will tell, but I'm happy they got me in so quickly and have at least tried to correct it. Hopefully the updates will help but I'd advise anyone with a first batch car to go and get the updates as there is a few needed

 

[Macadoodle]

Man I’m at my wits end with this car…
So while it was into the dealer for TPMS and stuck rear seat issues, I had a loan 5.
It was a joy to drive, flying up the bypass I use to go home with no issues.
Started cold, battery conditioner off (I checked).
My car tonight, same bypass, foot the floor, 61mph….!!!!!!!
Any speed limiting is off.
The speed sign thing is on, but was showing 70mph (so why stop me at 61mph…?)
I’m at a loss to explain why my car pleases itself what speed I’m limited to on the way home, no rhyme nor reason to it.
I’ve never felt such utter despair with a car…
Not something I can easily show to the dealer either as it seems to be peculiar to my journey home.
But it’s my bloody journey home and I can’t change that!
Honestly…61 foot to the floor…what the hell

On day 2 with my SE SR, still burning through the charge provided by the dealer but had it down to 16 % as I approached home.
Thinking of the issue you're experiencing, I floored it at this SOC and it responded briskly up to and beyond 60 mph until I let off.
So yes, definitely something amiss with yours, hopefully just a BMS glitch but a duff cell is also possible IMO, would explain why it only appears at a lower SOC.

 

[bowfer]

They said because 1 fault was charging related that it could have been triggering a low power mode
Time will tell, but I'm happy they got me in so quickly and have at least tried to correct it. Hopefully the updates will help but I'd advise anyone with a first batch car to go and get the updates as there is a few needed

I’ll wait for your update I think.
I simply cannot be bothered putting it back into the dealer again, I really think the next visit back to them needs to be the last.

TPMS system failure (all four wheels)
Steering vibration.
Stuck down rear seat due to failed central seat belt.
Oil leak.

I could suffer all of the above if the car drove well, which it’s capable of doing, but now this…?

Only had the car since 5/11 and spent around 7 days driving a loan ZS, 5 and Dacia Duster…

Sigh….

 

[M101]

I arrived at work today after driving 22 gentle miles from my last charge and its already down to 67% battery!
I guess its going back to MG again for an ultimatum visit! Make this a useable daily driven car or take it back and refund me!!

 

[tsedge]

I arrived at work today after driving 22 gentle miles from my last charge and its already down to 67% battery!
I guess its going back to MG again for an ultimatum visit! Make this a useable daily driven car or take it back and refund me!!

That's a shame. What about the power loss, was that any better?

 

[M101]

No power loss as i set off to work with 79% battery and its only happened twice before at 32% and 49% battery.
I've contacted MG and told them they must resolve this as i've bought a car that cant really be used for anything other than short journeys.
Im supposed to be going to Manchester tomorrow on a 100 mile round trip and im worried it wont make it.
To compare a colleague has a VW ID3 and she is only losing about 40 miles of range and is still able to get over 200 miles between charges.

 

[the briggie]

Sorry Michael did you say you set off at 79% and arrived with 67% after 22 miles..confused sorry?

 

[M101]

no, i've done 22 miles since the last charge which was done just before i took the car to MG yesterday and im already down to 67% battery.

 

[the briggie]

OK, so 100% going to MG and after total of 22 miles down to 67%. Roughly 1.3 miles per Kwh. Something smells off...