MG4 Software Update Thread

[GameZone]

No you don't have it wrong, Gary does.

There are different battery chemistries, which he should have mentioned:

For AC:

LFP/SR: 100% charging always is recommended.
NMC/LR: 80% normally, 100% once a month or if you need the range.

I got this information from MG!

DC charging is whatever you like but the last 20% will be very slow. Not recommended to take it right up to 100% on DC unless you need that extra range - and very impolite if there is a queue for the charger!

Why the difference between SR and Trophy?

 

[siteguru]

It's the difference between SR and LR ... LFP vs NMC chemistries. Topic has been done to death in other threads.

 

[tsedge]

Why the difference between SR and Trophy?

As @siteguru says, it is the difference between SR and LR battery types, nothing to do with SE vs Trophy spec.

 

[Tigger]

I have just had my annual service, including the updates R46, SC47, SCUK001, which I believe are standard for the Trophy. The result seems pretty good to me - I particularly like the new LKA, which is very restrained, and is now a positive safety feature (so far...)

I also like the new HVAC screen - it is less cluttered, with larger icons, which makes it usable while driving. I think I came across someone complaining about this screen - if so, I disagree. However, I do run the main screen permanently in dark mode, which increases contrast - I agree it is less good in light mode.

 

[GameZone]

I have just had my annual service, including the updates R46, SC47, SCUK001, which I believe are standard for the Trophy. The result seems pretty good to me - I particularly like the new LKA, which is very restrained, and is now a positive safety feature (so far...)

I also like the new HVAC screen - it is less cluttered, with larger icons, which makes it usable while driving. I think I came across someone complaining about this screen - if so, I disagree. However, I do run the main screen permanently in dark mode, which increases contrast - I agree it is less good in light mode.

What are SC47 and SCUK001?

 

[siteguru]

In my case (SE) they were this:

SC47 updated the CCU module (this may be why heating whilst plugged in not charging now works)
GW and IPK modules also updated
SCUK001 updated the BCM, EVCC and FDR modules

 

[Tigger]

It's interesting to see the UK in SCUK001 - maybe this is different in other countries?

 

[tsedge]

It's interesting to see the UK in SCUK001 - maybe this is different in other countries?

Almost certainly.

 

[Themist0]

Here is Gary’s (at MG) reply… he really has put doubts in my head as to what is the best practice… I think I’ll keep charging to 80% twice a week as don’t need huge range, and give it a100% monthly..

 

[Martinonline]

Perhaps you could refer him to the video of a scientist explaining that NMC batteries should not be kept at 100% and to the Canadian symposium where the professor explained the breakdown mechanism via the electrolyte at full charge. Sorry can't remember the links but will look.

Of course, he is probably correct if you use your car every day and don't leave it at 100%. But failure to explain that situation does not help matters. I suspect uninformed people will try to keep their cars at full charge even if they are not going to use it for a while particularly with the reduced range generated by the cold weather.

 

[RP67]

Almost certainly.

Speaking of other countries... I have my software "updated" yesterday, on my request to get some issue sorted, and to get OPD enabled. Also I asked the team to check my under tray, and I noticed the drive shaft end, and nut is kind of rusty, so I wanted some advice.

On pickup, they told me they updated a bunch of things (BMS, CCU, EVCC, FDR, FVCM, GW, IMCU, IPK), also they ordered a replacement under tray (I'm the first one here in NZ who has this issue), also the rust is normal...
As far I can tell, nothing changed (MPU, MCU sw version) or even under the "engineering info" everything appears to be the same. However, the ACC speed adjustment has been changed (long press vs short press), so that is more sensible now. I'm not sure whether the AEB or LKA improved, but certainly the ACC keeps the speed on small curves, which was not quite like this before, but still brakes every now and then, without obvious reason.

The best thing what I've got from this, I've got an MG ZS loaner. The software is pretty much same "under developed" as on my MG4, plus the driving comfort and responsiveness is way wore. I mean very bad, delay on acceleration, braking, spongy brake pedal and wobbly suspension. It was also 2023 car, travelled about 1000 km more than my MG4. So I getting more satisfied with my ride, and less critical about what annoys me. I would trade the ACC though, that was seamless on the ZS.

Anyone can tell me how/where else can I found information about the SW update in the MG4?

 

[RP67]

Perhaps you could refer him to the video of a scientist explaining that NMC batteries

I would rather avoid Gary in the future... it is a bad sign if you have to educate someone who should give you advice... It's probably just me.

 

[tsedge]

Here is Gary’s (at MG) reply… he really has put doubts in my head as to what is the best practice… I think I’ll keep charging to 80% twice a week as don’t need huge range, and give it a100% monthly..

This is contrary to everything I've learned about modern NMC batteries. I do think he is completely confused.

All NMC batteries have a finite lifespan, but it is very long. If thermally controlled, like on the MG4, typically they'll give 85-90% or even more of their original capacity after many years and after "going around the clock". Battery lifespan should not be a worry for the average user - there are many MG EV taxis out there reporting huge mileages are possible.

You can shorten the life of the battery, although it is debatable how big the effect of any of these is:

• Leaving it at a high state of charge (e.g. >80%) for long periods of time.
• Rapid charging constantly, due to the effects of very high input current (ie the ultra fast part of the charge curve).
• Failing to balance the battery for extended periods.
• Constantly topping up a little bit rather than waiting.
• Never draining the battery to a low SoC around 10%, apparently it likes it twice a year or so.

But this is not like some high-maintenance ICE car where you need to be tinkering with the valves and the timing every weekend - plenty of people will not know about the above or not do them and hire cars will be constantly abused - the evidence seems to be that it makes less difference than people think.

I have never heard of 80% being a DC only thing. Has anyone else?

 

[Ayoull]

This is contrary to everything I've learned about modern NMC batteries. I do think he is completely confused.

All NMC batteries have a finite lifespan, but it is very long. If thermally controlled, like on the MG4, typically they'll give 85-90% or even more of their original capacity after many years and after "going around the clock". Battery lifespan should not be a worry for the average user - there are many MG EV taxis out there reporting huge mileages are possible.

You can shorten the life of the battery, although it is debatable how big the effect of any of these is:

• Leaving it at a high state of charge (e.g. >80%) for long periods of time.
• Rapid charging constantly, due to the effects of very high input current (ie the ultra fast part of the charge curve).
• Failing to balance the battery for extended periods.
• Constantly topping up a little bit rather than waiting.
• Never draining the battery to a low SoC around 10%, apparently it likes it twice a year or so.

But this is not like some high-maintenance ICE car where you need to be tinkering with the valves and the timing every weekend - plenty of people will not know about the above or not do them and hire cars will be constantly abused - the evidence seems to be that it makes less difference than people think.

I have never heard of 80% being a DC only thing. Has anyone else?

DC charging leads to acceleration of lithium plating of the graphite anode in the battery, and at >80% this increases exponentially.

During use of the battery after charging, some plating will breakdown and become reusable lithium, some will become inert "dead" lithium that is no longer useable, some will remain on the anode and lead to increased battery resistance, the plating caused by DC charging is harder to breakdown as it is formed at higher temperatures than by AC lithium plating.

Leading to acceleration of battery degredation, some cells will degrade easier and faster than others like anything that is mass produced some perform worse than others, but the fundamental science is the same.

 

[Tigger]

Intermittent wiper update? I drove home from Greenwich tonight in light drizzle using intermittent wipe, and it seemed to be different. Crossing Blackheath at 24mph the wipe interval was typically 9 seconds, but occasionally it was much shorter - one or two seconds. I don't think it was doing this before my software update.

Anybody else noticed this, or is it my imagination?

 

[tsedge]

DC charging leads to acceleration of lithium plating of the graphite anode in the battery, and at >80% this increases exponentially.

My understanding is this is exactly why the car limits the charge rate at higher SOC: to manage this effect, also taking into account the battery temperature. Rates at high SOCs (>80%) typically always drop down to AC charging levels, protecting the battery.

During use of the battery after charging, some plating will breakdown and become reusable lithium, some will become inert "dead" lithium that is no longer useable, some will remain on the anode and lead to increased battery resistance, the plating caused by DC charging is harder to breakdown as it is formed at higher temperatures than by AC lithium plating.

Understood. These higher temperatures are typically associated with the peak charge rate rather than just the SOC though, are they not? This would mean, for example, that Rapid charging on a hot summer's day after a long drive would do the most damage. Is that what you are saying?

Leading to acceleration of battery degredation, some cells will degrade easier and faster than others like anything that is mass produced some perform worse than others, but the fundamental science is the same.

But this says nothing of leaving the battery for extended periods at a high SOC - it is my understanding this is worse for the battery than rapid charging per se.

And all of this assumes that the manufacturer has not already dealt with this in the BMS, buffer capacity and algorithms.

 

[Swift]

Intermittent wipe update? I drove home from Greenwich tonight in light drizzle using intermittent wipe, and it seemed to be different. Crossing Blackheath at 24mph the wipe interval was typically 9 seconds, but occasionally it was much shorter - one or two seconds. I don't think it was doing this before my software update.

Anybody else noticed this, or is it my imagination?

Maybe the behaviour has changed slightly but it's always done this. The faster you drive the shorter the interval gets. It also does an additional wipe when you pass certain speed thresholds - I've noticed it when you start moving from a standstill, then at about 10 mph, then again at 30 mph.

 

[Themist0]

I think I’ll just stick to my normal charging routines, only 100% monthly following my afternoon nap…️

 

[Ayoull]

My understanding is this is exactly why the car limits the charge rate at higher SOC: to manage this effect, also taking into account the battery temperature. Rates at high SOCs (>80%) typically always drop down to AC charging levels, protecting the battery.

The anode and battery have already been heated due to high current by this point, as such the DC charging has already caused higher levels of lithium plating than AC charging as temperature is an accelerator of the process.

Understood. These higher temperatures are typically associated with the peak charge rate rather than just the SOC though, are they not? This would mean, for example, that Rapid charging on a hot summer's day after a long drive would do the most damage. Is that what you are saying?

The MG4 charging curves which I can't post here as the forum doesn't permit SVG images, drops to 3ph AC levels (circa 22kW) around 90% and it's been found to be around 30-40kW is the point where higher levels of heat are produced in a battery while charging. This is ignoring any cooling system available on a battery however and even then two identical cars won't perform the same here due to deterioration of coolant with age.

But this says nothing of leaving the battery for extended periods at a high SOC - it is my understanding this is worse for the battery than rapid charging per se.

Hi levels of soc and allowing lithium plating to stay in situ for extended periods make it hard to breakdown.

Think of it like Weetabix in a bowl, of you wash it straight away it ls easy to clean it, leave it a day and you might as well bin the bowl and start again.


LFP is more resilient to lithium plating due to its structure being far more stable and rigid athan NMC which can suffer crystalline collapse if too much lithium plating occurs

 

[tsedge]

Thanks for the explanations it all makes sense.

I'm going to continue to keep my car at 80% normally, 100% when I need it and rapid charge to any level needed. I'm confident that this will be fine long term.