BMS update- feedback from MG

[bloggsy]

I picked up the wife's brand new ZS EV Exclusive from the dealers today and put it straight onto charge when I got it home.

My smart meter showed it was drawing a constant 7Kw from my Pod Point until fully charged with 459 Volts and a GOM of 167 miles showing.

My dealer said my car had come straight from MG with all the latest updates but how can I check?

Cheers

Bloggsy

 

[JodyS21]

I picked up the wife's brand new ZS EV Exclusive from the dealers today and put it straight onto charge when I got it home.

My smart meter showed it was drawing a constant 7Kw from my Pod Point until fully charged with 459 Volts and a GOM of 167 miles showing.

My dealer said my car had come straight from MG with all the latest updates but how can I check?

Cheers

Bloggsy

I'm sorry but that indicates that it does not have the latest updates on it, otherwise it would top out at the lower figure of about 449/450V maximum charge.
Did you reset the Accumulated trip before you got that 167miles reading (and with car started without brake pedal depressed so under no load).

Easiest way to check software versions is to buy a £15 obd2 dongle and install the android app.

Project OBD2 - Mobile App v1.2.1 and later

Edited: Working mobile phone app (Android only) 👇DOWNLOAD👇 v1.2.1 out 02.03.21 👆DOWNLOAD👆 [ Coulomb edit 2: See also version 2.xx.5 in this post. ] [ Coulomb edit 3: The link immediately above now has version 2.8.0, also called V2.8. Discussion here. ] [ Coulomb edit 4: Version 2.9.0 is here...

www.mgevs.com

 

[Cocijo]

are there three top end voltage versions around? 449/450 454/455 and 459/460?

 

[Srp111]

I'm sorry but that indicates that it does not have the latest updates on it, otherwise it would top out at the lower figure of about 449/450V maximum charge.
Did you reset the Accumulated trip before you got that 167miles reading (and with car started without brake pedal depressed so under no load).

Easiest way to check software versions is to buy a £15 obd2 dongle and install the android app.

Project OBD2 - Mobile App v1.2.1 and later

Edited: Working mobile phone app (Android only) 👇DOWNLOAD👇 v1.2.1 out 02.03.21 👆DOWNLOAD👆 [ Coulomb edit 2: See also version 2.xx.5 in this post. ] [ Coulomb edit 3: The link immediately above now has version 2.8.0, also called V2.8. Discussion here. ] [ Coulomb edit 4: Version 2.9.0 is here...

www.mgevs.com

Unless there is even newer software coming straight from the factory

 

[Cocijo]

Another thought crossed my mind that by reducing the high end cell voltage in subsequent bms updates, cars that were effected by the faulty bms software would take less time to get back in balance - maybe why MG did it as well as cell high-end protection?

 

[bloggsy]

I'm sorry but that indicates that it does not have the latest updates on it, otherwise it would top out at the lower figure of about 449/450V maximum charge.
Did you reset the Accumulated trip before you got that 167miles reading (and with car started without brake pedal depressed so under no load).

Easiest way to check software versions is to buy a £15 obd2 dongle and install the android app.

Project OBD2 - Mobile App v1.2.1 and later

Edited: Working mobile phone app (Android only) 👇DOWNLOAD👇 v1.2.1 out 02.03.21 👆DOWNLOAD👆 [ Coulomb edit 2: See also version 2.xx.5 in this post. ] [ Coulomb edit 3: The link immediately above now has version 2.8.0, also called V2.8. Discussion here. ] [ Coulomb edit 4: Version 2.9.0 is here...

www.mgevs.com

Yeah - that's what I was afraid of!

I didn't reset the trip and I can't remember if I pressed the brake pedal, but I've reset it now and I'll check without using the brake pedal and keep an eye on it.

I've got a couple of dongles I use for my car (it's an Outlander PHEV), so I'll give them a try and update this post next week.

Thanks for the info!

Cheers

Bloggsy

 

[sbwithers]

I'm making progress - voltage has increased from 426V to 446V. I should hit 450V within 2 weeks. I'm still only getting about 90 miles under similar conditions to last Feb where I would get 110 miles. I'm hoping this comes good.

My car was effectively 25kWh available. MG have me a dealer demo car and that car developed the same decline. By 7000km, the range is down to 150km....if you're careful.

They updated my software with a newer version and returned my car to me. I've been driving it 160km each day and getting it down to under 10% and then slow charging it back to fully equalised each night. The pack voltage has been steadily rising...from 432v to 443v (today). The range is increasing. To get the pack low enough I had to be less efficient and use the aircon and I still ain't home with more left over then a week ago. But I'd like to understand the impact of capping the voltage at 450v. What's the effective range then?

 

[a6taxipl]

Another thought crossed my mind that by reducing the high end cell voltage in subsequent bms updates, cars that were effected by the faulty bms software would take less time to get back in balance - maybe why MG did it as well as cell high-end protection?

My fully charged car shows 456V, A(bought Nov 2020) few days ago dealer said no updates for it. Yeah....

 

[Cocijo]

The dealers are soooo off the pace

 

[JodyS21]

Another thought crossed my mind that by reducing the high end cell voltage in subsequent bms updates, cars that were effected by the faulty bms software would take less time to get back in balance - maybe why MG did it as well as cell high-end protection?

That's an interesting suggestion.
It is true it probably would take longer for everyones cars to balance if going to the higher 455 odd. Although saying that now, I'm not sure it would in reality be much different as they'd just charge a bit higher before then starting the balance.


"are there three top end voltage versions around? 449/450 454/455 and 459/460?"
I'm pretty sure there's only 2 - the 450(+/-1), then the higher 455-457 version - I think maybe the way it did things before potentially allowed a bigger variation in total voltage voltage.

 

[Cocijo]

That's an interesting suggestion.
It is true it probably would take longer for everyones cars to balance if going to the higher 455 odd. Although saying that now, I'm not sure it would in reality be much different as they'd just charge a bit higher before then starting the balance.


"are there three top end voltage versions around? 449/450 454/455 and 459/460?"
I'm pretty sure there's only 2 - the 450(+/-1), then the higher 455-457 version - I think maybe the way it did things before potentially allowed a bigger variation in total voltage voltage.

You’ve really got your head around this battery tech stuff now! You’re fast becoming the forum BMS guru. And soon to be a youtube star I’m informed! really good and interesting work. I’m seeing quite a few owners reporting 459v full charges - seems very high?

 

[JodyS21]

My car was effectively 25kWh available. MG have me a dealer demo car and that car developed the same decline. By 7000km, the range is down to 150km....if you're careful.

They updated my software with a newer version and returned my car to me. I've been driving it 160km each day and getting it down to under 10% and then slow charging it back to fully equalised each night. The pack voltage has been steadily rising...from 432v to 443v (today). The range is increasing. To get the pack low enough I had to be less efficient and use the aircon and I still ain't home with more left over then a week ago. But I'd like to understand the impact of capping the voltage at 450v. What's the effective range then?

See What happens at a very Low State of Charge

Our test shows that the real usable percentage of the battery seems to be similar with the old and new max voltage, 92-93%.

 

[JodyS21]

You’ve really got your head around this battery tech stuff now! You’re fast becoming the forum BMS guru. And soon to be a youtube star I’m informed! really good and interesting work. I’m seeing quite a few owners reporting 459v full charges - seems very high?

I think to be honest the quoted 455V is a bit misleading, most people with the old version have around 457 odd voltage. I get the impression that 455v was kinda quoted as the figure that if you've got this then you're ok.
The way it previously decided at which point to cut off charging must've been based on different criteria which led to a bigger tolerance in final total voltage (and/or it balanced differently this letting the total voltage get higher).
- Probably getting as high as 459V isn't great for the battery long term.

 

[Cocijo]

Yes - I thought that. If you’re getting 459v you don’t want to leave your pack sat fully charged for long. That is nearly +10v above the MG latest ‘battery saver’ 449v update.

 

[bloggsy]

Having fully charged overnight, and left it on charge to balance, it showed 456V this morning and we took it for a wee run along the coast (40 - 60 mph roads and no harsh accelerating), covering about 60-ish miles.

We used 2 'bars' of battery power (we did pop into Tesco for a loaf of bread and used the Pod Point for a 20 mins top up before coming home, though) and the GOM was showing 114miles range left. Outside is gloriously sunny and about 15 C.

I've not had the chance to get my 'dongle' (oo-er missus! ) out as I've now got an iPhone so will have to use my tablet to pair it.

Cheers

Bloggsy

 

[Lovemyev]

I'm not convinced there's a obvious reason for how long the balance takes.
Except when due to the problem BMS it's way out of balance and goes for 10 hours.

My car has always been ok & balanced every charge etc, yet it seems to be pretty random how long it balances for - always not ages just a few hours.

I guess it's all chemistry so nothing definitive in how evenly the battery cells discharge, different days after the same journey they'll be very slight differences in cell voltage balances. We are only talking a handful of milli-volts but it can be enough to be a couple of hours difference in balancing time.

If your battery is already at a well balanced state, I don't think it's really necessary to let it do a full balance after every charge. The difference in voltage/SoC/range isn't much if it's at a reasonably balanced state.
It's quite possible that the subsequent discharge following a charge, could end up balancing the cells a bit more; so why waste the electricity/pennies that it takes to do a balance every charge...
That said when I can do a scheduled 7kwh charge soon, I'll prob effectively just set the start time to when my off-peak rate starts and then let it go as long as it likes and balance!

Thanks for the feedback @JodyS21 .
Still under travel restrictions in Wales, so usage is still very low.
Did a charge / balance from about 60 miles of remaining milage on the GOM last night on "Off-Peak" rate.
Plugged in and just let it charge, not sure what time it completed, but it did balance okay because the car had ended the charge on the wall box.
This morning I booted up the car ( foot off the brake ) etc.
The voltage was flickering between 250 volts and 249 volts, it finally settled at a steady 249 volts.
Both trips had been reset and the predicted range on the GOM was 161 miles.
I have witnessed the same figures reported on a couple of occasions now after a full charge / balance.
I totally agree with you, there does not appear to be much point in charging my car to 100% and balancing every single time at the moment, when I do not need ALL this range for just small trips.
I some how feel I am trying to balance a battery, that is not that far out of balance in the first place, given the voltage / range figures it is returning at the moment.
My car never received any of the "Buggy" software updates anyway.

 

[JodyS21]

Thanks for the feedback @JodyS21 .
Still under travel restrictions in Wales, so usage is still very low.
Did a charge / balance from about 60 miles of remaining milage on the GOM last night on "Off-Peak" rate.
Plugged in and just let it charge, not sure what time it completed, but it did balance okay because the car had ended the charge on the wall box.
This morning I booted up the car ( foot off the brake ) etc.
The voltage was flickering between 250 volts and 249 volts, it finally settled at a steady 249 volts.
Both trips had been reset and the predicted range on the GOM was 161 miles.
I have witnessed the same figures reported on a couple of occasions now after a full charge / balance.
I totally agree with you, there does not appear to be much point in charging my car to 100% and balancing every single time at the moment, when I do not need ALL this range for just small trips.
I some how feel I am trying to balance a battery, that is not that far out of balance in the first place, given the voltage / range figures it is returning at the moment.
My car never received any of the "Buggy" software updates anyway.

450/449V rather than 250/249 I hope.........
Mine very often does this btw, as in the app I see it flicker between 449.75 & 450.0

 

[Lovemyev]

450/449V rather than 250/249 I hope.........
Mine very often does this btw, as in the app I see it flicker between 449.75 & 450.0

Yeah - Sorry .
I had 240 volts swishing around inside my mind, because yesterday I was installing some new LED down lights on our kitchen ceiling !.
Turned out to be a bit of a nightmare job.
Hopefully finish it today .

 

[bloggsy]

So, just went out and checked the car after charging it overnight and left to balance.

It now shows 457V and 139 miles on the GOM. Outside is a sunny day and about 16 C.

I plugged in a couple of dongles but unsure of which app to use. the one I downloaded from Google Play (sorry - I can't remember its name now!) didn't show the SOH or SOC or any EV info. It did have a table with a section for these details, but they were blank.

What apps are you guys using to monitor your data?

Cheers

Bloggsy

 

[JodyS21]

So, just went out and checked the car after charging it overnight and left to balance.

It now shows 457V and 139 miles on the GOM. Outside is a sunny day and about 16 C.

I plugged in a couple of dongles but unsure of which app to use. the one I downloaded from Google Play (sorry - I can't remember its name now!) didn't show the SOH or SOC or any EV info. It did have a table with a section for these details, but they were blank.

What apps are you guys using to monitor your data?

Cheers

Bloggsy

Project OBD2 - Mobile App v1.2.1 and later

Edited: Working mobile phone app (Android only) 👇DOWNLOAD👇 v1.2.1 out 02.03.21 👆DOWNLOAD👆 [ Coulomb edit 2: See also version 2.xx.5 in this post. ] [ Coulomb edit 3: The link immediately above now has version 2.8.0, also called V2.8. Discussion here. ] [ Coulomb edit 4: Version 2.9.0 is here...

www.mgevs.com

Reset the Accumulated Trip to get a comparable GOM reading, otherwise it's based on your previous driving data (and start the car without pressing brake pedal so it is under no load/the HV battery isn't on)