Battery equalisation on ZSEV Trophy LR

[fred12345]

Ok, so this is getting to be an older thread now but I did say I'd come back to you all with more info about my NMC battery equalisation experiences.

Firstly, I can say quite categorically that my ZS EV does not equalise it's battery at anytime if the slow charge is started & the 'low battery' warning has not been given. It is imperative that the low battery warning has been given first prior to charging as per the owners manual for the MK2's. This ensures the cars battery management system takes full control of the whole charge. Smart charging (eg: Octopus Energy IG) should be turned off to avoid the network pausing the charge which can stop the equalisation from happening even when it resumes. The charge must not be interrupted. On the facelift MK2 EV's low soc warning is at 20%.To be sure all battery cells are below the 20% soc level I've found it best to go to 17 or 18% before charging.

I have found that equalisation charging at 100% takes around 12-15mins. During that time the charge rate drops progressively from 7.1kw to eventually 200w & 100w. After that my full range seems improved a little & the GOM certainly seems more accurate. The car shows routinely 325-329+ miles after the equalisation in eco mode. Eco being the mode all manufacturers show their range in. My actual range last week in eco mode showed an easy 279miles. Running the battery down to 10%, if I had done that, would have given me just a bit under the lower gom figure probably at around 305 miles. So that is an extrapolated figure.

So, I still don't understand why some people on here are saying they can equalise at any state of charge. Mine won't & neither will my friends ZS MK2 EV. I'm guessing software has changed. Anyway, that is my experience which is as the owners manual says.

Thanks for detailed post. I charged mine to 100% quite a few times from various percentages and from what I can see, there is always balancing at the end when the charge reduces from 3kW (granny charger) towards 1kW or less for random amounts of time, sometimes 15 min, sometimes much longer. I can only assume it's doing the balancing... Mine is 2022 standard range MK2 model...

 

[Data]

Thanks for detailed post. I charged mine to 100% quite a few times from various percentages and from what I can see, there is always balancing at the end when the charge reduces from 3kW (granny charger) towards 1kW or less for random amounts of time, sometimes 15 min, sometimes much longer. I can only assume it's doing the balancing... Mine is 2022 standard range MK2 model...

Thanks Fred. The LFP batteries seem to do that ok.

 

[Lovemyev]

Ok, so this is getting to be an older thread now but I did say I'd come back to you all with more info about my NMC battery equalisation experiences.

Firstly, I can say quite categorically that my ZS EV does not equalise it's battery at anytime if the slow charge is started & the 'low battery' warning has not been given. It is imperative that the low battery warning has been given first prior to charging as per the owners manual for the MK2's. This ensures the cars battery management system takes full control of the whole charge. Smart charging (eg: Octopus Energy IG) should be turned off to avoid the network pausing the charge which can stop the equalisation from happening even when it resumes. The charge must not be interrupted. On the facelift MK2 EV's low soc warning is at 20%.To be sure all battery cells are below the 20% soc level I've found it best to go to 17 or 18% before charging.

I have found that equalisation charging at 100% takes around 12-15mins. During that time the charge rate drops progressively from 7.1kw to eventually 200w & 100w. After that my full range seems improved a little & the GOM certainly seems more accurate. The car shows routinely 325-329+ miles after the equalisation in eco mode. Eco being the mode all manufacturers show their range in. My actual range last week in eco mode showed an easy 279miles. Running the battery down to 10%, if I had done that, would have given me just a bit under the lower gom figure probably at around 305 miles. So that is an extrapolated figure.

So, I still don't understand why some people on here are saying they can equalise at any state of charge. Mine won't & neither will my friends ZS MK2 EV. I'm guessing software has changed. Anyway, that is my experience which is as the owners manual says.

We have had our Trophy LR ( NMC battery type of course ) for over 3 years now and charge exclusively from a wall box at home. Never charged from any external chargers, that includes rapid units.
The car is charged to 80% SOC for 99% of the time, only charging to 100% on a few occasions.
From day one I have reset the trips before charging and the GOM regularly predicts a range of 212 miles in the default mode of normal on boot up.
This can be lower when it is really cold .
On numerous occasions, I have tried to catch our car commencing the balance cycle, by monitoring our home energy unit.
I can see no evidence that this is the case, so yes balance cycle starts after the battery has reached 100%.
We had the original ZS EV ( Gen1 ) with the smaller NMC battery first, and I have witnessed that balance after 100% charge many times.
Same NMC battery chemistry, so no surprise there then !.
Our car has now covered 26,000 miles and some battery degradation is evident.
The new MG5S model has a LFP battery but the LR has the NMC battery chemistry, which is interesting.

 

[Data]

We have had our Trophy LR ( NMC battery type of course ) for over 3 years now and charge exclusively from a wall box at home. Never charged from any external chargers, that includes rapid units.
The car is charged to 80% SOC for 99% of the time, only charging to 100% on a few occasions.
From day one I have reset the trips before charging and the GOM regularly predicts a range of 212 miles in the default mode of normal on boot up.
This can be lower when it is really cold .
On numerous occasions, I have tried to catch our car commencing the balance cycle, by monitoring our home energy unit.
I can see no evidence that this is the case, so yes balance cycle starts after the battery has reached 100%.
We had the original ZS EV ( Gen1 ) with the smaller NMC battery first, and I have witnessed that balance after 100% charge many times.
Same NMC battery chemistry, so no surprise there then !.
Our car has now covered 26,000 miles and some battery degradation is evident.
The new MG5S model has a LFP battery but the LR has the NMC battery chemistry, which is interesting.

That's very interesting Lovemyev. Thanks for injecting that info. So it's probable your car hasn't equalised for some time? My 80% charge gives me a bit more range in normal mode than your car is reporting. Not forgetting the range shown is also dependant on how the vehicle has been driven of course. But if you have reset the GOM I'm thinking you may still recover some extra range if you did a full BMS/equalisation charge as per the book. Worth a go.
Most of the time I too go to 80% & normally don't go below 40%. This gives me ample range for everyday driving & doesn't stress the battery. I love to hear what other folks are doing. Thanks again.

 

[Lovemyev]

The charging advice for the NMC battery iis a little contradictory in my mind really ?.
On one hand, it suggests that you should be charging to 80% SOC to improve the long term health of the pack, then only charge to the max 100% for the occasional longer trips, As charging to 100% constantly WILL speed up the degradation of the pack ?.
So, if the balance cycle only commences after 100% SOC has been reached, then what are you expected to do ?.
The advice for the LFP packs are completely different, they encourage you to charge from any SOC level.
What is the age of your car and how many miles has it covered ?.
If you reset your trips, then charge to 80% SOC, what is your predicted range in default normal mode ?.

 

[Data]

The charging advice for the NMC battery iis a little contradictory in my mind really ?.
On one hand, it suggests that you should be charging to 80% SOC to improve the long term health of the pack, then only charge to the max 100% for the occasional longer trips, As charging to 100% constantly WILL speed up the degradation of the pack ?.
So, if the balance cycle only commences after 100% SOC has been reached, then what are you expected to do ?.
The advice for the LFP packs are completely different, they encourage you to charge from any SOC level.
What is the age of your car and how many miles has it covered ?.
If you reset your trips, then charge to 80% SOC, what is your predicted range in default normal mode ?.

Yeah, I don't think there is any sort of contradiction in the advice about how we treat our batteries. Just some fear about going to 100% especially with the NMC packs, which is quite understandable. Folks think their NMC battery pack is going to be toast very quickly if they do that. In fact that doesn't seem to be the case. One of my neighbours has a Tesla with an NMC battery. It was new just over 3yrs ago. He goes to 100 % 75% of the time. The battery SOH is at 95% with 61,000 miles on the clock, he tells me. He goes to 100% so he doesn't have to charge on his longer journeys. He rarely goes below 20% SOC. He has the car on a 4yr lease so I guess he's not too bothered about how long the battery lasts. However, I doubt the battery will fail or degrade anytime soon.

I'm intent on keeping my ZS for quite some time so it seems prudent to treat the battery in the best way I can. Therefore I use 100% only for equalisation, about every 8-10 weeks, or for my very long runs.

My own car's range at 80% charge is variable of course, dependant on how it's been driven. But typically it's between 235-245 miles in NORMAL mode. I'll be going to 80% later this week so I'll take a picture if I think of it & post.

 

[Lovemyev]

My own cars range at 80% charge is variable of course dependant on how it's been driven. But typically it's between 235-245 miles in NORMAL mode. I'll be going to 80% later this week so I'll take a picture if I think of it & post.

That would be great to see.
Do you zero your accumulative total trip meter when taking your results ?.
235 - 245 miles of predicted range sounds more like the prediction in ECO mode not NORMAL mode ?.
Our car predicted 211 - 213 miles of range when charging to 80% SOC.
This was consistent every time for at least the first 18 months or so.

 

[Data]

Yes, generally I zero my trip but not always. I've had 80% charge with 225 miles showing on one or two occasions in normal mode. I think that's the lowest 80% mileage I've ever had showing in 'normal' mode. But that was after some more enthusiastic driving with quite a load & not clearing the trip meter so it predicted accordingly. It was after that I did the equalisation. It made a difference, predicting another 14 miles of range in normal mode on that occasion at 80% charge. The highest range predicted at 100% charge in normal mode has been 315 miles. I tend to record my miles covered between charging & I have to say most of the time the predicted range is not far out. Sometimes slightly less but sometimes a little more than predicted. Of course, I don't run my battery pack right down because that's not a good thing to do. But it's easy to extrapolate what the maximum range is. I don't know how this compares to most others but seems not too far different to a pal of mine with the same ZS EV as me. Currently the car is showing 152 miles at 50 % soc in normal mode.

 

[JohnV6]

I have just equalised mine. I have never reset the trip since I got it in Jan. It shows 268 miles range at 100%.
The weighted average miles per kWh is 3.42 meaning at 75 kWh I have in theory 256.5. On the last run it did on that trip 3.7 miles per kWh implying 277.5 miles.

The screen display for the 3620 miles driven is showing 3.2.
A lot of the driving is high speed dual carriage way. I know if I run on B roads I can get easily 4.4. I run it in normal mode with a good deal of cruise control due to avg speed cameras on the A12 & A14.

 

[Data]

John, it sounds like you & me drive the same roads but I don't use the A12 & A14 everyday. As I'm now retired I don't have the need to dash about too much so I get quite good miles per kwh. Typically I cruise at 60mph these days unless I have somewhere to be at a specific time. My miles per kWh vary of course but I can often get a surprise when I see the figure fluctuating between 4.5 & 4.8 miles on mixed driving. I don't drive aggressively either, rarely flooring it. But I don't drive like a granny either. This certainly helps the range. I also have to go cross country on A & B roads quite a bit which further lowers my speeds, probably spending more time at 50-55mph. Again that makes a huge difference to range & is often more enjoyable than continuos motorway type driving. I take full advantage of the excellent sound systems we have in our cars which certainly keeps everything relaxed & unhurried.

John, did you buy yours new? I got mine new.

 

[JohnV6]

Yes new via CarWow for 23k in Jan.
Sub 60 I agree makes a huge difference. But with power at 7p/ kWh the saving is nothing.

 

[Data]

Absolutely John. 7p per kWh is great. I'm currently saving around £70-£80 pm by having an EV. I think many EV sceptics don't realise just how much money you can save. I'm a relatively low mileage car driver these days 6-7k miles per year (I do another 6k miles on my motorcycle). I'm sure many folks on here are saving much much more than me.

 

[Data]

T

Yes new via CarWow for 23k in Jan.
Sub 60 I agree makes a huge difference. But with power at 7p/ kWh the saving is nothing.

Thats a good price John. I paid £24k for a new unregistered car on the road in January. I got a very good trade in deal though on my Citroen. So I'm happy. We both got a lot of car for our money!

 

[JohnV6]

Indeed. Is it any wonder European car makers are in trouble.

 

[Kithmo]

Absolutely John. 7p per kwh is great. I'm currently saving around £70-£80 pm by having an EV. I think many EV sceptics don't realise just how much money you can save. I'm a relatively low mileage car driver these days 6-7k miles per year (I do another 6k miles on my motorcycle). I'm sure many folks on here are saving much much more than me.

I had a Prius and the cost of fuel per mile, averaged over a year, was around 16p, with my MG4 it's less than 4p. Even at my low mileage of 2.6k a year, I'm saving £300 a year in fuel, that almost pays for the insurance.

 

[Lovemyev]

Yes, generally I zero my trip but not always. I've had 80% charge with 225 miles showing on one or two occasions in normal mode. I think that's the lowest 80% mileage I've ever had showing in 'normal' mode. But that was after some more enthusiastic driving with quite a load & not clearing the trip meter so it predicted accordingly. It was after that I did the equalisation. It made a difference, predicting another 14 miles of range in normal mode on that occasion at 80% charge. The highest range predicted at 100% charge in normal mode has been 315 miles. I tend to record my miles covered between charging & I have to say most of the time the predicted range is not far out.

The WLTP figure put out by MG for the LR at 100% SOC is 273 miles of range, if I remember correctly ?.
So, when the car is brand new with the trips zero’s out and a full 100% charge, the predicted range SHOULD match the WLTP figure.
They have designed it this way, other manufacturers very likely do the same.
They have built in a buffer at the head of the pack and also a bottom buffer that owners do NOT have access to.
So, when the pack displays full or empty, it never really is due to this protection.
Why do they do this ?.
Well, the top buffer is there because they know that the battery degeneration when new, will be higher than latter in its life cycle.
To avoid scarring the owners, with this quick reduction in range, they build the buffer into the software.
The bottom buffer is very important as it is there to protect the pack from totally bricking, which can become a totally unrecoverable situation.
Zeroing out the trips, and powering up the car in the default modes, will give the owner a brief but fairly accurate, insight on battery degradation, regardless of how the car has been driven historically.
You are using a common known base line each and every time.
If you charge to 80% SOC and the predicted range is above say 211 - 213 miles, say 225ish miles, then this is an over inflated figure and is unachievable by a pack of that capacity.
The 211 - 213 figure from rest with ALL electrical equipment turned off should be constant, the only mitigating factor will the outside temperature.
So in winter time this predicted figure will likely drop to about 209 ish ?.
But will recover as the weather improves.
Any figure reported LESS than 211 - 213 at 80% is pack degradation.
I have followed this this process on both models of the ZS EV over roughly 4 years now and it’s proven to be trust worthy.
When the health of the pack had been checked by the OBD port, it confirms what I see myself.
Our Trophy model is three and a half years old and the car has covered 26,000 miles.
I first spotted slight degradation at about 18 months old, when the predicted range dropped to about 210 - 209 miles ?.
On both models, this tended to happen suddenly.
Then as time moves on, the decline is slow, but there never the less.
My last charge reported a predicted range of 200 miles at 80% SOC which would suggest a SOH of around 96 ish % ?.

 

[Data]

That's a nice report back Lovemyev. You are on the right track. But if I may say, just a couple of things you haven't got quite right just based upon what you have explained.
The WLTP figure is a slightly mystical figure, achieved by some but not others & based on European union testing in a lab that is supposed to represent real driving conditions or near to it. It doesn't really and they know this. But instead the WLTP figures act as a yardstick to compare all makes of car to. That is the actual intention of the WLTP figure & not to give highly accurate or representative range figures. That's impossible due to all the variables a car encounters. At 100% soc your battery should read much more than 273 miles. 273 is an average figure which require a much higher mileage range to be showing. They all go through exactly the same testing. Some like me exceed that figure quite often. Remember too that nearly all manufacturers quote there range figures in ECO mode. NOT normal mode. MG tells me all their figures are in eco mode.
My MG ZS EV LR at 100% soc in eco mode has a maximum range of 387 miles, according to MG's blurb. That's in eco mode probably at 30mph! Obviously, no one drives at 30mph all the time but it must be achievable otherwise they cannot say that. When I witnessed WLTP testing being carried out many years ago we had many black suits from Brussels witnessing the testing & results. So it's pretty well policed. The most range I've ever achieved on a 100% charge was 305 miles. At 100% predicted range my car was showing 322 in eco. That last bit of range was extrapolated to avoid me taking the battery down below 17%. As it was I covered 268miles in eco or thereabouts but had I kept driving to near zero percent then I would undoubtedly have achieved near to 305 or above. I then proceeded to do my first battery equalisation.
So while I agree with much of what you say, you are missing talking about the bigger picture which is almost everything about our cars range is dynamic, variable, not fixed! The biggest variable is us the drivers. So even with everything reset & charged we may get similar predicted range (but not always), that range will almost always vary & change from driver to driver as we drive. But I do see where you are coming from on this. It's all quite exciting I think & I'm still learning about my car & it's ability to cover miles.

 

[wattmatters]

We bought a Dec 2022 ZS EV recently (Excite model with 49 kWh battery). It was basically "new old stock" with 5 km on the odometer. Shortly after getting it home I added it to Home Assistant.

This has been the normalised range estimate and economy in the past 90 days:

Varies with conditions and type of driving.

Can see in recent couple of weeks an increase in consumption / drop in normalised range, which is associated with doing more higher speed km on the local highway (multiple trips to regional airport), else it's mostly my wife doing local driving at modest speeds on local country roads.

 

[Lovemyev]

That's a nice report back Lovemyev. You are on the right track. But if I may say, just a couple of things you haven't got quite right just based upon what you have explained.
The WLTP figure is a slightly mystical figure, achieved by some but not others & based on European union testing in a lab that is supposed to represent real driving conditions or near to it. It doesn't really and they know this. But instead the WLTP figures act as a yardstick to compare all makes of car to. That is the actual intention of the WLTP figure & not to give highly accurate or representative range figures. That's impossible due to all the variables a car encounters. At 100% soc your battery should read much more than 273 miles. 273 is an average figure which require a much higher mileage range to be showing. They all go through exactly the same testing. Some like me exceed that figure quite often. Remember too that nearly all manufacturers quote there range figures in ECO mode. NOT normal mode. MG tells me all their figures are in eco mode.
My MG ZS EV LR at 100% soc in eco mode has a maximum range of 387 miles, according to MG's blurb. That's in eco mode probably at 30mph! Obviously, no one drives at 30mph all the time but it must be achievable otherwise they cannot say that. When I witnessed WLTP testing being carried out many years ago we had many black suits from Brussels witnessing the testing & results. So it's pretty well policed. The most range I've ever achieved on a 100% charge was 305 miles. At 100% predicted range my car was showing 322 in eco. That last bit of range was extrapolated to avoid me taking the battery down below 17%. As it was I covered 268miles in eco or thereabouts but had I kept driving to near zero percent then I would undoubtedly have achieved near to 305 or above. I then proceeded to do my first battery equalisation.
So while I agree with much of what you say, you are missing talking about the bigger picture which is almost everything about our cars range is dynamic, variable, not fixed! The biggest variable is us the drivers. So even with everything reset & charged we may get similar predicted range (but not always), that range will almost always vary & change from driver to driver as we drive. But I do see where you are coming from on this. It's all quite exciting I think & I'm still learning about my car & it's ability to cover miles.

You make some very valid points regarding the expected WLTP range here of course.
Maybe I will put it another way, the most important fact when it comes the results you see displayed by the car after trip reset and charged and balanced to 100% is this.
You power up the car and nothing else.
It displays a “predicted” range on the GOM that COULD wishfully achieve, this purly based on what capacity the battery can store at that precise moment in time.
You now repeat the very same test in two years time, when the car has likely been charged multiple times and spent some time on a rapid chargers maybe.
Which can degrade the pack even faster than using a wall box.
You have covered….. say 24,000 miles over the two years.
You are now asking the car the very same question, under the very same parameters.
100% charge / trips reset every thing.
The pack is unable at this point, to receive the same level of capacity that it once did due to the degradation, because we all know that batteries degrade over time.
Will return the same predicted range as it did when new ?.
No of course it won’t.
That reduced predicted range figure has now fallen, from what it once was two years ago.
There is your battery degradation there !.
I have owned a plug in hybrid before converting to full EV about 5 years ago.
They all displayed the same behaviour, so this is a common factor with HV batteries.

 

[Data]

You make some very valid points regarding the expected WLTP range here of course.
Maybe I will put it another way, the most important fact when it comes the results you see displayed by the car after trip reset and charged and balanced to 100% is this.
You power up the car and nothing else.
It displays a “predicted” range on the GOM that COULD wishfully achieve, this purly based on what capacity the battery can store at that precise moment in time.
You now repeat the very same test in two years time, when the car has likely been charged multiple times and spent some time on a rapid chargers maybe.
Which can degrade the pack even faster than using a wall box.
You have covered….. say 24,000 miles over the two years.
You are now asking the car the very same question, under the very same parameters.
100% charge / trips reset every thing.
The pack is unable at this point, to receive the same level of capacity that it once did due to the degradation, because we all know that batteries degrade over time.
Will return the same predicted range as it did when new ?.
No of course it won’t.
That reduced predicted range figure has now fallen, from what it once was two years ago.
There is your battery degradation there !.
I have owned a plug in hybrid before converting to full EV about 5 years ago.
They all displayed the same behaviour, so this is a common factor with HV batteries.

Of course you are correct, pretty much. But we all know this so what point are you making?