Is this SoH OK?

[Data]

I have to say, that I do find MG’s advice on charging and balancing for NMC type battery chemistry, a little bit contradicting myself ?.
On one hand they tell you to carry out a balance cycle about every month, right okay.
Then go on to recommend that charging to 80% SOC for your “every day” shorter trips, is encouraged for the “long term health of your battery”.
Save charging to 100% for when you are making the less frequent longer trips folks is the word.
Well we know that NMC batteries only perform a “correct” balance cycle, when commencing from a low SOC, then the balance cycle will start, only after the pack has reached 100% SOH.
I struggle to understand just how these two recommendations align then really ?.
Can’t see how you are expected to observe the advice of charging to 80% AND follow the instructions on balancing the pack every 4 - 6 weeks, which necessitates a 100% charge and some more.
The advise on LFP packs is much more simple, use it and then plug it in when you get home.
Just charge it 100% as often as you like !.
Balancing here can’t be overlooked of course.

Yes, it's seems a bit contradictory. But the damage/degradation the battery experiences by NOT doing a regular 100% full & proper equalisation is much worse than if you do it. NMC batteries are not fragile although that's the impression we can sometimes get from reading some stuff that's out there. We know NMC doesn't have quite the same life cycle as LFP but the reality is it isn't ever going to matter to 99.9% of people especially if you look after it a bit, or even if you don't. I've calculated my NMC battery will last over half a million miles & probably 20+ years the way I use my car & charge it. You can charge them to 100% as often as you need to. The operative words here are 'if you need to'. I equalised to 100% during last week as I had a trip to make. Doing so gave me an estimated range on the GOM of 310 miles in normal mode. Of course, I didn't get that as I was driving on motorways mostly. But range was good. Ambient temp was 7C. It's surprising how range is improved by doing regular equalisation & calibration at 100%. And it's only every 5-6 weeks for me. That seems the sweet spot the way I use my car.

Curious, how long does balancing take you if you charge to 100% from let’s say 80% or does it not happen at all?

You know, I haven't actually tried that Mickey. If I'm going to 100% I like to get the BMS to recalibrate too. So I normally would go from around 18% soc, just under the battery low warning message. The rest of the time for daily driving I tend to keep the battery between 45 & 70% soc. According to the Battery University, that's a good area to keep the battery at which can make the battery last 22-24 years if it's NMC. They stress the battery must be equalised on a regular basis whether NMC or LFP.

 

[Lovemyev]

I have had our ZS EV LR for 14 months and only done about 7,000km so I only do 100% twice a year.

As a low milage user case and an almost new pack, then I would not expect to see any battery degradation this early in its life.
Even when only charging to 100% twice a year, but this could change as time moves on of course .
I have said this before I know sorry, but if your car is either a lease / PCP or your like to exchange it fairly often etc.
Then people really tend not to be really interested in the long term health of their packs tbh.
Any acceleration in the degradation caused by the first owner, is passed down along the line.
In this respect ICE vehicles are no different really, hire / lease / loan cars can suffer a hard life in the early years, but this misuse only starts to manifest itself as problems later, after the car has moved on.
This is combated by moving them on WAY before they become trouble some.
There cheaper prices naturally make them attractive to car super markets of course.
But they could be hiding a dark secret of neglect.
Speaking personally, I would never buy a second hand car without seeing the V5C document first, if its previous been a hire car etc then it’s time to be heading for the door.

 

[Data]

As a low milage user case and an almost new pack, then I would not expect to see any battery degradation this early in its life.
Even when only charging to 100% twice a year, but this could change as time moves on of course .
I have said this before I know sorry, but if your car is either a lease / PCP or your like to exchange it fairly often etc.
Then people really tend not to be really interested in the long term health of their packs tbh.
Any acceleration in the degradation caused by the first owner, is passed down along the line.
In this respect ICE vehicles are no different really, hire / lease / loan cars can suffer a hard life in the early years, but this misuse only starts to manifest itself as problems later, after the car has moved on.
This is combated by moving them on WAY before they become trouble some.
There cheaper prices naturally make them attractive to car super markets of course.
But they could be hiding a dark secret of neglect.
Speaking personally, I would never buy a second hand car without seeing the V5C document first, if its previous been a hire car etc then it’s time to be heading for the door.

Yes, I tend to agree. But I think these batteries are proving very robust overall. My neighbour who lives just a bit up the road from me has a Tesla with the long range NMC battery. I don't know what size it is, but that's not important. The car is on a 4yr lease & is 3yrs old with just under 80,000 miles on the clock. He charges it every other day to 100%. The car shows his battery SOH at 96%. So no worries there. He only 'fast chargers' away from home once a week on average. That may be a factor in how well the battery is doing.

 

[AnaloguePete]

I assume that’s a typo, otherwise you would have barely added 15kWh?

No. No typo. 2.3kW for 7 hours adds 2.3 x 7 kWh = 16.1 kWh.

 

[Susanna]

I have tried several times to get the Vgate iCar Pro to connect to the car/app, but either the dongle is faulty or there’s an issue with the socket in the car. I only get a solid red light, and intermittent green and blue when plugging/unplugging. It’s going back to Amazon as ‘faulty’. Disappointing, but hey ho!

 

[Data]

Susanna, it's unlikely to be a faulty unit especially with the VGate. What scanner app are you using? It's nearly always the app that won't allow a connection. You may need to try other apps to find the one that works. Follow the downloaded connection instructions to the letter. It will work with the right app. Assuming that your phone linked up to the VGate but not the app. There are very specific instructions to follow. It can be different for different apps. The OBD2 port will be ok. Never ever found one that's faulty in all the years I worked in the trade.

 

[MickeySw]

No. No typo. 2.3kW for 7 hours adds 2.3 x 7 kWh = 16.1 kWh.

Charging isn’t 100% efficient but that’s beside the point, adding just 15kWh into the HV battery isn’t sufficient to do a BMS calibration?

 

[AnaloguePete]

Charging isn’t 100% efficient but that’s beside the point, adding just 15kWh into the HV battery isn’t sufficient to do a BMS calibration?

No, it won't. If I run it down to around 15%, it'll need an 85% charge to get it up to 100%, which on the granny charger, I calculated, will take over 18 hours.
That's 43 kWh at 2.3kW. It's too long to have the car out of action, so I'll leave the job until I've got a 7kW charger.

 

[MickeySw]

You know, I haven't actually tried that Mickey.

I’m wondering if you’re up for an experiment (if you have a means of measuring cell voltages using OBD). Charge to 100% (no BMS calibration) and take note of the min/max values, then compare them with what you get after your regular routine.

 

[Data]

I have measured the battery voltages per cell using OBD2 reader at 100% without doing an equalisation. I don't know if I've still got them noted down. I remember they were not too bad regarding balance at that time. From memory the car was just 2 months old. I do know after a full equalisation & recal the cell balance was great. I'll try it at some point soon.

 

[Susanna]

@Data I tried these 2, followed all the instructions, several times, but couldn’t get a green light connection at all.
Thank you for your help, but I’m just not up to trying yet again!

 

[Data]

Just remembered that when I did the 100% charge without a balance the car still had regen braking available, as normal. Mostly you'd think that shouldn't be. Yet the charge had finished. When I do a full equalisation to 100% from just below the low battery warning, smart charging turned off, there isn't any regen braking available as the cells are all completely full. Just thought I'd add that in to the equation. As I increased the time & mileage between full equalisation & calibration charges this regen was more noticeable as the car still gave maximum regen at 100% after a normal non equalisation charge to 100%. That was another little sign that was telling me that I needed to equalise more often.

@Data I tried these 2, followed all the instructions, several times, but couldn’t get a green light connection at all.
Thank you for your help, but I’m just not up to trying yet again!
View attachment 42840View attachment 42841

Susanna, try 'eZS'. It's very much a suck it & see for most of us. This one has worked ok for quite a few people with the VGate reader. Let us know how it goes. You should have a choice of several scanners available through the documentation that came with your reader. Frustrating though it is, you will find one that works if eZS doesn't.

 

[MickeySw]

I do know after a full equalisation & recal the cell balance was great. I'll try it at some point soon.

Great top balancing is fine and well, but the really interesting values (for you) would be in the 45-70% SoC bracket?

 

[Steve Kaye]

I bought a 71/2022 Mk2 ZS EV about a year ago. I have just installed the eZS app (great app!) and it tells me that the battery SoH is 85.4%. Is this normal for a 4-year-old car?

Do you mean the I Smart App?
Where is the SOH I cant see it there

 

[Coulomb]

Do you mean the I Smart App?

No, eZS is an enthusiast written app for Android only. Search the Google app store for eZS if you have an Android phone.

 

[decrep]

I have

Susanna this is sooo far off topic an administrator should probably remove it.

But latst night in my dreams you were driving a bus with Susanna license plates.
I insisted on cleaning those plates while you were stopped at a bus stop. I had to finish quick as you were in a hurry to move on.

Now what do you think a dream analyser would make of that?

 

[Everest]

Susanna this is sooo far off topic an administrator should probably remove it.

But latst night in my dreams you were driving a bus with Susanna license plates.
I insisted on cleaning those plates while you were stopped at a bus stop. I had to finish quick as you were in a hurry to move on.

Now what do you think a dream analyser would make of that?

Hmmm... now, in that dream did you also have a banjo on your knee?

I had a dream the other night
Everything was still
I dreamed I saw Susannah
She was comin' down the hill (oh, Susannah)
Oh, oh, oh, Susannah
Don't you cry for me (oh Susannah, oh Susannah)
'Cause I come from Alabama with my BANJO on my knee
(Oh Susannah, oh Susannah)

 

[decrep]

Hmmm... now, in that dream did you also have a banjo on your knee?

You know how dreams are, but I don't think Banjos have any association for me.

 

[Susanna]

@decrep - that’s totally bizarre! I used to drive our 9m tag axle motorhome (and thoroughly enjoyed so doing), but sadly no personalised reg plate. No fare paying passengers though. And definitely no banjo!!!

 

[Susanna]

@decrep - weirdly, I did have to wipe over the reg plates on my MG yesterday, as they (like the rest of my car) were really filthy. And I was in a hurry…….