MG4 Battery Degradation

[fnegroni]

Percentage that display car may drift.
that because it’s calculated by BMS to kWh in and out from low SOC to 100%
On my Atto 3 60.48 kWh that 4 month not done calibration cycle it displays
13.6%=10 kWh that means 0.735 kWh 1%

That reminds me, when the SoH of my SE SR went up by a 0.25%, I had just done a 7% to 100% plus balancing in one single charge. Although I used to do this quite regularly (every 2 months) before and the SoH never increased.
The logic must be more complicated than initially thought.

 

[Romeo77]

That reminds me, when the SoH of my SE SR went up by a 0.25%, I had just done a 7% to 100% plus balancing in one single charge. Although I used to do this quite regularly (every 2 months) before and the SoH never increased.
The logic must be more complicated than initially thought.

I had balancing issues with my car, so every cycle have slightly different remains kWh at 100%
For owner who not using obd2 to look further the fact of lost capacity will be understandable as degradation of battery but there might be also high delta because balancing not done long time and there might be some loss of capacity because of that.
BYD not described in owner manual how battery to be balanced and when balancing starts, take for me some time to understand and adopt my charging habits to that, it’s balanced when charging finished and not need to be connected to EVSE, just should be stationary and powered off.
Not owning charging point so always charged on municipal charging points and after reaching 100% drive away (goodbye balancing).

 

[Rolfe]

I don't really understand how it works. I was told my battery is at 100% at the one year check, although I'm not sure if I believe that. I decided to do a <10% to 100% charge at the end of last week and went down to 6% on Friday. However I interrupted the charge three times to go aurora watching, so I don't know if it actually counts.

Nevertheless by the end of it all I had 50 miles more range than I've seen since about August. Which could be entirely down to the fact that we suddenly leaped from winter to summer on Friday. Who knows.

 

[gdog]

Hello,

I hope everyone is doing well. I am revisiting the topic: are you still noticing a loss of 0.01% per day, or has it stopped? I think I have found a way to stop this loss and even to increase the capacity by at least 0.30% at least once a month, which would offset the daily loss.

Do tell more.

 

[seamust1000]

I have an X Power, I've never been asked to balance the batteries, after 6000 miles, ABRP is now telling me that the car has 0.2% battery degredation

 

[Romeo77]

I have an X Power, I've never been asked to balance the batteries, after 6000 miles, ABRP is now telling me that the car has 0.2% battery degredation

For my Atto 3 (sorry not MG4 SR) ABRB think i have 5% degradation but with one of OTA we get change for BMS and now it shows 1% at 58.6 kWh and not at 60.4 kWh used (they just build bigger bottom buffer i can see that because 1% now at higher cell’s voltages of cell’s then before- 2.9 v and that because too much drivers wanted to be zero hero and we know how that finishes with lfp discharge curve )
My pack from factory is 153 kWh, after calibration half year ago is 151.47 ah so that definitely not 5% degradation.
More to say i think that BMS calculated 151.47 ah because i did calibration with unbalanced battery.
ABRB not counting battery bottom buffer as usable capacity I think and counting from how many kWh used and added from 0% to 100% as reported by car, and see that as battery degradation because that number is smaller then nominal capacity.

 

[Tangoed Man]

I believe you have very odd opinions about the Leaf, despite never having driven one.

I have had two of the original Leaf's; one 24kWh and a 30kWh. Both were absolutely terrible for battery degradation, and it was the second most talked about subject on the Leaf forum I used.

 

[siteguru]

You're talking to fresh air - that's a year-old post and the poster has been banned.