MG ZS EV MK2 - LFP (standard range) - Battery SOH Theory

[fred12345]

Good to see the programmed decline of 0.01% each day has stopped.

A bit surprising to see that it happened before your service already. Did you get a software update at any time?

My 2 year service is in about 6 weeks time. I'll see whether that makes any difference.

I don't think there was any software updated, I got mine second hand in April and pretty sure there were no previous updates ... To be honest, I don't want any - everything on the car works and I'm not going to risk any new update messing it up ...


One odd thing I noticed this time when I plugged my cheap ODB reader - SoC showed 87% but the car was showing 67% on screen ... ?

 

[Outbackozzie]

My 2023 ZS EV SR just did a thing!
Always charged to 100% daily at council 11kW charger, discharged daily to 10%.

 

[Narrowgauge725]

First service 12 and 10,500 ish miles SOH 100%

 

[fred12345]

First service 12 and 10,500 ish miles SOH 100%

that's unusual, who measured it, garage or you?

 

[Narrowgauge725]

that's unusual, who measured it, garage or you?

Garage so do you trust them?

 

[fred12345]

Garage so do you trust them?

I wouldn't expect 100% from a brand new car, that's why I said it's unusual... Read some threads about ODB 2 reader (cheap Bluetooth plug-in) and how to measure it yourself. Quite easy and you can buy them on AliExpress or Temu for £3-£5

BUT - don't get obsessed about it, the car will serve you for years and years in any event. Long Range as far as I remember should be charged up to 80% and only when you really need it, to 100%.

 

[Narrowgauge725]

I wouldn't expect 100% from a brand new car, that's why I said it's unusual... Read some threads about ODB 2 reader (cheap Bluetooth plug-in) and how to measure it yourself. Quite easy and you can buy them on AliExpress or Temu for £3-£5

BUT - don't get obsessed about it, the car will serve you for years and years in any event. Long Range as far as I remember should be charged up to 80% and only when you really need it, to 100%.

Yes I only charge to 80% except twice a month when I do 175 trip down to Huddersfield and then 100% to go back also probably only 6 rapid charges in the 12 months.

 

[king31]

I wouldn't expect 100% from a brand new car, that's why I said it's unusual... Read some threads about ODB 2 reader (cheap Bluetooth plug-in) and how to measure it yourself. Quite easy and you can buy them on AliExpress or Temu for £3-£5

BUT - don't get obsessed about it, the car will serve you for years and years in any event. Long Range as far as I remember should be charged up to 80% and only when you really need it, to 100%.

Hi,
What's your SOH today? Has the 0.01%/day loss stopped or continued?

 

[fred12345]

Hi,
What's your SOH today? Has the 0.01%/day loss stopped or continued?

This was on 29.03.2025
Let me know your calculations, I didn't count days...

 

[king31]

This was on 29.03.2025
Let me know your calculations, I didn't count days...

Thank you for your quick response. Unfortunately, I see that the loss continues. We're really dealing with a purely software limitation.

I have a Standard MG4 with an LFP battery, and I notice this decrease every day, as well as with every excessive acceleration and every DC charge. I managed to raise the SOH by discharging the battery to 0% SOC BMS, but since the 2-year service, the BMS seems frozen and refuses to raise it.

Today, I'm at 94% SOH with 49,000 km and 25 months of use. My car was produced on 13/11/2022. Last year, I managed to raise the SOH several times by reaching 0% and then trickle charging to 100%, without interrupting the charge or connecting to the car.

 

[fred12345]

Today, I'm at 94% SOH with 49,000 km and 25 months of use. My car was produced on 13/11/2022. Last year, I managed to raise the SOH several times by reaching 0% and then trickle charging to 100%, without interrupting the charge or connecting to the car.

I decided not to worry about it too much..
By the way, read somewhere that draining the battery to 0% could damage it... But don't remember if that was about my mobile or about the car ...