MG Owners > 1 year .. Battery Health

[Paul225]

Sorry, Not sure what you are trying to show?

No point in using anything for comparison other than getting the figures after doing a full AC charge and balance - don't do any miles etc, unplug it and get the reading straight away - start without brake pedal pressed to ensure the HV battery is under no load.
Make sure the accumulated trip says zero so that the range calculation is using the default settings, if it has any data on the trips then the range calculation shown will be based on your diving data stored and not the default driving data.

Thanx will do

 

[Gomev]

This article about the new Tesla 4680 battery goes someway to explaining simply why it is not a single big battery. It's to do with heat dispersion.

Panasonic Bets Big On Tesla's New 4680 Battery Cells | Carscoops

Panasonic could sell the innovative new battery cells to other companies

www.carscoops.com

 

[Cocijo]

Interesting - thanks.

 

[andras]

I'm on 14,000 miles with a reported 98.7% SOH, however the SOH stayed at 100% for ages then has recently started dropping quickly from 100%. I cannot detect any change in range, or amount to charge the car, but then I probably would not notice 1.3%.
I wonder how MG measure the SOH? Is it based on the number of charges, the mileage, the internal resistance, the max battery voltage etc. Without knowing how MG measure it, it is impossible to know whether to believe the result.
I'm using the Thai app to display the SOH.

Is it possible to get some clarity on what the Thai app is that you’re using? I’m really new to this and I would like to get an undersea of my cars battery health on a regular basis.

 

[JMX]

I’ve done 50,000 miles over 2 years and SOH 98%

 

[Lovemyev]

I’ve done 50,000 miles over 2 years and SOH 98%

Can I ask, is your car running on the original software from the factory, or has it had the BMS update applied ?.
What is your percentage of fast A/C charging to D/C rapid charging ?.
Thanks !.

 

[JMX]

Can I ask, is your car running on the original software from the factory, or has it had the BMS update applied ?.
What is your percentage of fast A/C charging to D/C rapid charging ?.
Thanks !.

Its had all the BMS updates done, including a few months running the dodgy version with range issues. Always charged it using 7kw home charging and only used DC rapid chargers a couple of times.

 

[Coulomb]

Is it possible to get some clarity on what the Thai app is that you’re using?

Sure:

Thai Android App 2022 latest version

[ Edit Coulomb: Version 2.9.0 is here. ] If anyone with a MKI MG ZS EV wants the latest (V2.8) version of the Thai ‘Android’ app here is the download link Please note the battery % is approximately 5% out due to the Thai BMS being set up differently to European models🙂

www.mgevs.com

If you want more background, there is a long thread on the previous version of that app here:

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

[ Edit: had the wrong link for the older app. ]

 

[Lovemyev]

Its had all the BMS updates done, including a few months running the dodgy version with range issues. Always charged it using 7kw home charging and only used DC rapid chargers a couple of times.

Many thanks !.
How are you viewing your HV battery SOH can I ask ?.
Are you using a OBD dongle ?.
What is your reported range on the GOM after a full charge & balance in normal mode ?.

 

[JMX]

Many thanks !.
How are you viewing your HV battery SOH can I ask ?.
Are you using a OBD dongle ?.
What is your reported range on the GOM after a full charge & balance in normal mode ?.

Using OVMS. GOM Range on normal and a/c off is usually around 160 after full charge and balance.

 

[Lovemyev]

Using OVMS. GOM Range on normal and a/c off is usually around 160 after full charge and balance.

Can not argue with that then !.
163 miles was the base line set after the BMS update, full charge and balance, both trips reset and no HVAC running and in normal mode.
50,000 miles covered and a SOH of 98% after two years, a lot better result than others have seen !.
Our previous ZS EV Gen 1 was two years old and had covered about 20,000 miles.
Charged at home on a 7 Kw wall box, it would only estimate 156 miles after a full charge and balance.
BMS update done on the 15th Jan 20.
A date burnt into my mind .
I did not have OVMS but it was pretty obvious there was some battery degradation present, as a fairly long known journey that we covered when the car was new, could still be made okay, but the remaining range ( SOC ) was a LOT less after two years.
Other owners have reported similar results.
Your SOH of your pack is really good .

 

[Harry]

Someone asked me the other day ‘why doesn’t your car just have one big battery?’ Which is an interesting question that makes you think of why battery packs are built from many individual cells - the benefits and the downsides.

It is inevitable that as the batteries age some cells will outperform others. At this point the bms tries to protect these degraded cells from further damage (as it has done since they were new).
If it were possible for example to isolate these degraded cells, then the remaining pack would show good health. It’s usually a few degraded cells that can affect how the pack as a unit performs.

This is one of the reasons why manufacturers first look to replace cells to bring a pack back to an acceptable level of health before considering replacing the whole pack.
I wonder if a customer could in the future buy just a pack of cells and replace the under-performing ones rather than the complete pack? I guess adding new cells might also put pressure on the other ageing cells in the pack so the only real longer term solution is a new pack? But it would certainly be cheaper for cars that are out of warranty.

I use quite a few lion batteries at home for security cameras etc and the same batteries with the same use have variations in performance and longevity so I guess this is normal.
My iPhone tells me that my battery health is 98% but i’ve no idea how it calculates this - I would guess it has to be voltage, but as with our cars showing a voltage and also being able to perform under high rates of discharge and load are different areas.

Individual cells provide very low voltage. Think of an ordinary AA "battery" - it is not a battery it is a single cell - output 1.5v DC. If you made a huge one- size of your house - it would still be 1.5 volts. It would last a long time... To increase the voltage you need to connect many cells together - in series - not in parallel. Your ordinary "12 volt" car battery needs 6 cells in series to get its voltage. In other words, each cell delivers only roughly 2 volts. Therefore to build a high voltage battery - a battery meaning many cells - you need hundreds of separate cells. Nominal voltage of a lithium ion cell is 3.7, so to get a 400 volt battery you need 108 separate cells connected in series. An electric car will have several of these batteries connected in parallel, the number depending on the capacity of the individual cells and the overall capacity required for range.

 

[Harry]

This article about the new Tesla 4680 battery goes someway to explaining simply why it is not a single big battery. It's to do with heat dispersion.

Panasonic Bets Big On Tesla's New 4680 Battery Cells | Carscoops

Panasonic could sell the innovative new battery cells to other companies

www.carscoops.com

It cannot be a single big cell (a battery is by definition many cells) as that would have only 3.7 volts and wouldn't pull the skin off a rice pudding.