Recent BMS update

[Lovemyev]

The new maximum voltage will be around 449/450V (assuming no loads on like climate etc). The minimum voltages have been adjusted to keep the range equal.

Thank you @MilesperkWh .
This has confirmed my theory then that the pack voltage had been reduced for some reason after the Jan 15th update.
Yes - we need to balance our packs IF they have been affected by any of the previous “Buggy” software BMS issues.
But if like me, you never had the “Buggy” BMS updates and you have been updated to the latest update released Jan 15th - then your pack is less likely to be badly affected.
So, in affect the longer your car has been running on the “Buggy” versions, the more likely your pack will be affected.
It’s just plain common sense really.
Reducing the voltage at the factory from 455 volts down to around 449 - 450 volts may have been as a result of cars blowing the HV fuse !.
In affect, the software released on the 15th Jan should correct all of the problems encountered by the previous versions of updates in my book.
Please feel free to correct me if I am wrong here please @MilesperkWh .
If my theory is correct, then chasing the previous 455 volts once seen on the pack prior to the latest update after a full charge, is totally futile !.
If your HV battery has been badly affected by previous “Buggy” versions and your pack voltage is down at 430 volts, then yes there is improvement to be made for sure.
I appears that the 455 volt unicorn has been overruled by the new kid on the block.
The target now is the same as the production models leaving the factory then at 450 volts ?.

 

[Cocijo]

Just a thought... So... if MG have adjusted the max voltage to 450v from 455v to improve battery life - but adjusted the lower end to maintain range with no battery detrimental impact - why not do that with the 455v and get better range in the first place?

 

[Cocijo]

And if the battery has been modified from the configuration that took the original test and got 163miles - wouldn’t that mean the WLTP tests will need reconfirming? without independent tests the modified battery range cannot be confirmed can it?

 

[Miles Roberts CG]

And if the battery has been modified from the configuration that took the original test and got 163miles - wouldn’t that mean the WLTP tests will need reconfirming? without independent tests the modified battery range cannot be confirmed can it?

If the overall usable capacity remains identical, then it doesn't need retesting.

 

[Cocijo]

Thank you @MilesperkWh .
This has confirmed my theory then that the pack voltage had been reduced for some reason after the Jan 15th update.
Yes - we need to balance our packs IF they have been affected by any of the previous “Buggy” software BMS issues.
But if like me, you never had the “Buggy” BMS updates and you have been updated to the latest update released Jan 15th - then your pack is less likely to be badly affected.
So, in affect the longer your car has been running on the “Buggy” versions, the more likely your pack will be affected.
It’s just plain common sense really.
Reducing the voltage at the factory from 455 volts down to around 449 - 450 volts may have been as a result of cars blowing the HV fuse !.
In affect, the software released on the 15th Jan should correct all of the problems encountered by the previous versions of updates in my book.
Please feel free to correct me if I am wrong here please @MilesperkWh .
If my theory is correct, then chasing the previous 455 volts once seen on the pack prior to the latest update after a full charge, is totally futile !.
If your HV battery has been badly affected by previous “Buggy” versions and your pack voltage is down at 430 volts, then yes there is improvement to be made for sure.
I appears that the 455 volt unicorn has been overruled by the new kid on the block.
The target now is the same as the production models leaving the factory then at 450 volts ?.

As usual I think you summarise very well and in a nice style. I still have concerns about how fragmented updates appear to be. I now understand that charging whilst unlocked is a separate update to any BMS configuration having initially thought that the two things were part of an overarching BMS update that also included the ability to complete a timed home wallbox charge. The comfort updates are also separate items I believe. Historically owners have had one update only to find it has affected other items - and this has been put down to application error by the operator at the dealership. Now the battery pack voltage has been adjusted downwards to improve longevity. Without software release notes it does get very confusing and is not confidence inspiring - and that’s one of the reasons why there are so many questions. MG dealerships do try to help but there aren’t many that seem to have the knowledge and provide the information that Chorley Group do. Many users seem to make a long round trip just to buy a car from them and get the updates with good back up information. Whilst this is commendable to Chorley other dealers should also step up and follow their lead - for example get on the forum and take part in discussions instead of leaving Chorely to take all the questions

 

[jamesie]

It would be even more useful, imo, if someone from the Technical Department in MG participated.

It's great to have Miles as part of the forum and podcast. The information is much welcomed.

 

[Mark Holmes]

As usual I think you summarise very well and in a nice style. I still have concerns about how fragmented updates appear to be. I now understand that charging whilst unlocked is a separate update to any BMS configuration having initially thought that the two things were part of an overarching BMS update that also included the ability to complete a timed home wallbox charge. The comfort updates are also separate items I believe. Historically owners have had one update only to find it has affected other items - and this has been put down to application error by the operator at the dealership. Now the battery pack voltage has been adjusted downwards to improve longevity. Without software release notes it does get very confusing and is not confidence inspiring - and that’s one of the reasons why there are so many questions. MG dealerships do try to help but there aren’t many that seem to have the knowledge and provide the information that Chorley Group do. Many users seem to make a long round trip just to buy a car from them and get the updates with good back up information. Whilst this is commendable to Chorley other dealers should also step up and follow their lead - for example get on the forum and take part in discussions instead of leaving Chorely to take all the questions

Well said

 

[SCB86]

I have the latest update and can now charge whilst unlocked. Voltage has dropped from 455v to 449v but my range hasn't changed.

 

[Lovemyev]

If the overall usable capacity remains identical, then it doesn't need retesting.

Hi @MilesperkWh .
Thank you for the on my views on the new voltage settings !.
At the first chance, I will be paying a visit to the Chorley dealership, to get my inconsistent charging rate sorted on my car after receiving work at another dealership.
I am compiling data and spoken to the Tech Team at Rolec.
It is the car and NOT the wall box that is responsible for the cars strange charging behaviour.
This will get your EV Tech’s scratching their heads !.
It is NOT going back to the original dealer that’s for sure.
I hope to be paying you a visit ASAP !.

 

[AbuG]

An update that increases the battery range to the level of the newly released "Gen2" in India would be well appreciated, and possibly make up for some of these short falls that we have seen.

 

[JodyS21]

It would be even more useful, imo, if someone from the Technical Department in MG participated.

It's great to have Miles as part of the forum and podcast. The information is much welcomed.

Definently agree there.
MG could do with some official input to discussions.

 

[JodyS21]

As usual I think you summarise very well and in a nice style. I still have concerns about how fragmented updates appear to be. I now understand that charging whilst unlocked is a separate update to any BMS configuration having initially thought that the two things were part of an overarching BMS update that also included the ability to complete a timed home wallbox charge. The comfort updates are also separate items I believe. Historically owners have had one update only to find it has affected other items - and this has been put down to application error by the operator at the dealership. Now the battery pack voltage has been adjusted downwards to improve longevity. Without software release notes it does get very confusing and is not confidence inspiring - and that’s one of the reasons why there are so many questions. MG dealerships do try to help but there aren’t many that seem to have the knowledge and provide the information that Chorley Group do. Many users seem to make a long round trip just to buy a car from them and get the updates with good back up information. Whilst this is commendable to Chorley other dealers should also step up and follow their lead - for example get on the forum and take part in discussions instead of leaving Chorely to take all the questions

I tried to get the full info from the dealer when I picked my car up.
I asked if I could get some screen shots/photos from the technician doing the updates.
Unfortunately no joy

Somewhere out there, we know for a fact, there is an update to some system/ecu/controller that causes some people to get the "fancy car graphics" vs boring text when changing modes. There's not much we can definitively differentiate between cars with supposedly all the latest updates, other than our guesstimates with battery/regen etc, BUT the graphics are either there or not therefore definitive.

 

[JodyS21]

And if the battery has been modified from the configuration that took the original test and got 163miles - wouldn’t that mean the WLTP tests will need reconfirming? without independent tests the modified battery range cannot be confirmed can it?

Personally I'm not convinced about the 163miles WLTP Combined range figure - WITH the current car we (I) have.
I know it's very cold right now but the range just does not seem good enough to me.

Mine is a new car that had done 13miles print to having the Jan update, so it shouldn't have any of the battery out of balance issues.
After a definite full granny charge:
Yesterdays 103mile journey, based on the trip data, used 34.23kWh of juice; with 16m left on the GOM = another 5.33kWh left in the battery pack. Giving total of 39.56kWh available battery capacity. I believe I did pay for a 44.5kWh of usable battery in the car.
I do not believe that 163 miles WLTP combined range can be achieved in the car on 39.56kWh of battery....

Also, personally I think that when the car is in an almost usable low power state, that should be the point at which is WLTP test is concluded.
If I can't use the radio when 25miles is left on the GOM & have stupidly reduced power, without the option to switch off the reduced power, then that's the "Real" usable range of the car.

(I really like the car by the way, some software changes could probably resolve All of the issues)

 

[Chrisb]

Took mine in for its first service on Tuesday, charged it today and it charged to 456v (after 6 hours balancing), it always used to charge to 455v, I think it's just coincidence and that maybe they've not done the recent update, not really bothered as my car still seems to have 42.5kw usable capacity.

 

[Lovemyev]

Somewhere out there, we know for a fact, there is an update to some system/ecu/controller that causes some people to get the "fancy car graphics" vs boring text when changing modes. There's not much we can definitively differentiate between cars with supposedly all the latest updates, other than our guesstimates with battery/regen etc, BUT the graphics are either there or not therefore definitive.

Hi Jody - My car ( Jan 2020 ) did have the fancy graphics when switching driving modes with the toddle switch.
I received the Jan 15th 21 update only two days after it was released.
I have not checked if the fancy graphics are still there, because I always drive in the default mode of normal and Regen 3 mode.

 

[Lovemyev]

Took mine in for its first service on Tuesday, charged it today and it charged to 456v (after 6 hours balancing), it always used to charge to 455v, I think it's just coincidence and that maybe they've not done the recent update, not really bothered as my car still seems to have 42.5kw usable capacity.

I would suggest that you have not had the update then.
Unless the car goes in for any other work, it will next year before you have it.
By then it could all be sorted ( or not ).

 

[Jake]

Just a bit curious as to why tweak the maximum voltage down to 450v from 455v to improve longevity of the battery pack? Do MG have doubts whether the usable life of the pack will extend throughout the warranty period? If so what happens to those that are still on the BMS version that charges to 455v max and may never be updated? Are they at risk of being warranty replacements say in years 5 or 6? That is sailing very close in specification terms and I would have thought a 10 year+ life expectancy for something that is warranted for 7 years to be more conservative.

 

[Chrisb]

I would suggest that you have not had the update then.
Unless the car goes in for any other work, it will next year before you have it.
By then it could all be sorted ( or not ).

Yeah I think they've not, although it did take them 2 hours, I had a waiting appointment and they took it in straight away, I've only ever charged mine up fully about three times anyway, usually plug it in for three hours once the car gets to two bars remaining and that takes it back to just over 80% full, I only charge and balance to full if I'm planning on a long journey, I plan on keeping the car as long as possible, so far it's been a great car for me, had no trouble at all.

 

[Lovemyev]

Just a bit curious as to why tweak the maximum voltage down to 450v from 455v to improve longevity of the battery pack?

I have a theory that MG have reduced the voltage on the pack because a number of cars have had the main HV fuse failure.
My local dealer had the fuse fail while carrying out the PDI checks !.
A second car arrived at the dealership on a flat bed with HV fuse failure.
Both cars where shipped out to another dealer about 40 miles away.

 

[Lovemyev]

I only charge and balance to full if I'm planning on a long journey, I plan on keeping the car as long as possible, so far it's been a great car for me, had no trouble at all.

I am of the same camp as yourself.
Only charging to the max 100% if I am taking on a long trip.
Not many of THEM going on at present !.
As a pretty good guide, a 7.0 kw wall box will give you roughly about 25 miles of range, for every hour that the car is on charge up to about 97 - 98% then the charge will throttle back to 3.6 kw's to reach 100%.
Then the car will commence the balancing process and reduce the charge to about 500 watts.