BMS update-Computer says “No”

[Mike]

I drove 84 miles again today. 5 stops. Arrived home with 21%. I had reduced power from about 40%. It was generally 2°C.

 

[RobMgZsEV]

@shikoku14 regarding your granny charge/455V are you able to charge car at home and tell exact amount of energy pumped in? so you drive from 100% to x% pluggin in charging to 100% and you know that 100% - x% = y kWh pumped in? my voltage is 439V and ive noted down some figures on mine which are 100% to 16% and pumped in 27kWh, and 100% to 29% pumped in 24kWh so avg from both days suggests about 33kWh battery available, i do have separate meter on wall charger

 

[BigEVuser]

I tried charging on slow last night ( 16A)... car is now full showing 137 miles but voltage is only showing 437 volts..So when it goes in on Monday I am hoping they can remove the BMS update... will feedback

 

[Mark Holmes]

I tried charging on slow last night ( 16A)... car is now full showing 137 miles but voltage is only showing 437 volts..So when it goes in on Monday I am hoping they can remove the BMS update... will feedback

Not sure if they can be removed only overwritten, I wonder is they can revert, that would be very interesting if they can..

 

[shikoku14]

Hi @RobMgZsEV I can, here are my last few chargers with my Ohme cable (obviously this adds in charging loss)

The last charge with the Ohme was adding 46% (the car when plugged in reported that it was at 54% 22.95kWh assuming 42.5 usable). 30th December it was at 48% (20.4kWh) and 28th I was at 22% (9.32kWh) (33.2 is about what I max out at in my 5 hour Octopus Go Faster window) these last two are a bit from memory, and Christmas drinks may affect the memory 1-2% either way! But its looking like its getting close to what 100% should be, I generally tell the Ohme to charge a couple of percent more than is needed to get to 100% to allow for charging loss, but I recall I didn't on the last charge.

Edited as I'd got my adding up wrong on amount remaining and what that would relate to in kWh left in the pack.

 

[RobMgZsEV]

Hi @RobMgZsEV I can here are my last few chargers with my Ohme cable (obviously this adds in charging loss) View attachment 1026
The last charge with the Ohme was adding 46% (19.55kWh assuming 42.5 usable) (the car when plugged in reported that it was at 54%). 30th December it was at 41% (17.43kWh) and 28th I was at 22% (9.32kWh) (33.2 is about what I max out at in my 5 hour Octopus Go Faster window) these last two are a bit from memory, and Christmas drinks may affect the memory 1-2% either way! But its looking like its getting close to what 100% should be, I generally tell the Ohme to charge a couple of percent more than is needed to get to 100% to allow for charging loss, but I recall I didn't on the last charge.

two of your charges are fairly close to 43kWh battery capacity, you pumped in 20kWh as for 46% used and 33kWh in as for 78% used so it looks ok, better than mine

 

[shikoku14]

I'll keep an eye on it over the next couple of weeks, not that I'm going to be needing to charge it probably, with WFH and the border radius of my town being a couple of miles in each direction this last charge should do me until Feb/March!

 

[Chrisb]

My car had all the updates done in August before I collected it, I bought an ex demo car which was registered February, I can charge with my doors unlocked and it doesn't have any bongs, I seem to recall they did 4 separate updates in total, just charged mine to 100% and it's was 455v on the dash.

 

[Mark Holmes]

All charged mine last night and this morning I had 454 volts, it may have lots a little overnight or perhaps I lost a little battery capacity over the 13,000 miles which isn’t so bad as degradation compared to other EV car makers...
I think Mike Proctor said he’d also only lost 1% over a year and 12,000 miles too.

 

[shikoku14]

I'm going to cross post this from speakev as Tim mentions there may be two BMS updates one from August (which will have been the one my car got) and one that came out in November this may explain the discrepancy in my figures to others who got their cars from Nov onwards - Lower range after Service

No, its not the battery heater update.

It's the BMS. And the BMS update changed sometime between August and November. August BMS update is ok. November BMS update kills range. First it makes the GOM go crazy, then it sorts itself out by using a really low miles per kWh. I believe the m per kWhr is not just measured, but estimated based on change in battery percentage, estimated battery capacity and miles traveled. With the bad BMS update, the battery capacity is considerably reduced, which then causes the car to give really bad miles per kWh as it tries to match battery percentage against the capacity which is much lower than it expects.

 

[Miles Roberts CG]

Hi all,
I've had confirmation today that MG has spotted a bug in the BMS code from the recent August/October updates.
It looks like the August update caused cell balancing issues when full (so the end balance took 5hours or so). They tried to rectify this in the October update, but then found that this caused cell balancing issues when SOC was lower. This has caused range issues, as the car isn't able to use the full pack capacity.
By the end of next week, there will be a new BMS update released to the dealer network, which will be able to fix the affected vehicles.

 

[MAS]

Thanks Miles, would there be a recall by the dealer to the affected owners based on their data or we are expected to contact the dealer?

 

[Miles Roberts CG]

It would be applied at next service time, unless the customer advises their dealer that they need it doing sooner. The dealer is unlikely to have a list of the cars which have had whichever update was available at PDI. Probably best if you tell them if you think it needs it.

 

[Richie]

Hi all,
I've had confirmation today that MG has spotted a bug in the BMS code from the recent August/October updates.
It looks like the August update caused cell balancing issues when full (so the end balance took 5hours or so). They tried to rectify this in the October update, but then found that this caused cell balancing issues when SOC was lower. This has caused range issues, as the car isn't able to use the full pack capacity.
By the end of next week, there will be a new BMS update released to the dealer network, which will be able to fix the affected vehicles.

Hi, that's good news. Can we assume that everyone can now have the latest version free of charge?

Having had an update on 12th November for the charge/unlock doors that did not work and then another update on the 1st December that did work. How can one very simply see which version was actually updated?

 

[MAS]

Thanks, for me service is 12 months away, only go the vehicle last week. I will contact dealer, see what they say.

 

[JohnG]

Miles many thanks for the update on the BMS SW problem. Do you know if this negates any issues with the "Coldgate" battery heating option that was made available end of last year and range issue were in fact related to the BMS update?

 

[Miles Roberts CG]

Hi, that's good news. Can we assume that everyone can now have the latest version free of charge?

Having had an update on 12th November for the charge/unlock doors that did not work and then another update on the 1st December that did work. How can one very simply see which version was actually updated?

Unfortunately, the software versions are only readable with the MG diagnostic laptop which the dealers use, so you'd have to take it to a dealer and ask them to check.

 

[Miles Roberts CG]

Miles many thanks for the update on the BMS SW problem. Do you know if this negates any issues with the "Coldgate" battery heating option that was made available end of last year and range issue were in fact related to the BMS update?

I don't know if it will fix all issues with the coldgate battery heater option, but it's certainly compatible with it, and should fix the range related issues. Not sure if it will actually make the heater work though.

 

[jamesie]

Many thanks Miles for keeping the members updated. It's very much appreciated.

 

[mystreet]

Many thanks to Miles for the update. My concern is that the update is going to be available next week, how much testing has been done to it. So yet again owners will become beta testers for MG again.

As to what is on my car, I will be contacting my dealer/MG to request all the information that they hold on me (subject access request) which they must supply. Including the service record as my car identifies me. Then we will see what is recorded .