64kWh Battery - 20 to 80% is the only safe way to charge?

[Tuareg]

Why do you pick chinese over european? Just for the price without sacrificing value?

As you stated, the majority of products sold on marketplaces such as Ebay, Amazon etc are all sourced from China and then sold for 2,3,4...10 times the price. Chinese workers need my money more than Europen (and definitely US, which I boycott anyway) workers and they produce fantastic products at great prices.

 

[Martinonline]

The extension lead shows the Australian 230v three pin system, also used elsewhere, eg china, at 220v.

I suspect there must be a 110V granny charger for those countries using that voltage.

 

[Bam Bam]

I do have a charger at home

Apologies I misunderstood and thought you were saying you had a window open because there was a cable coming out.

I don't think the AC speed will drop notably until you get to around 100%.

It is the DC speed that really slows down once you get over 85%.

 

[pollenface]

Australia has a different problem. We’re putting ours in all the wrong places, so nobody uses them

Haha very true

 

[Rolfe]

Hahaha I get it.

Yeah at 19% I had 90 km left and didn't feel safe running for longer... like... Oh no if "something" happens ill be hanged somewhere.

So I returned home, changed plans, and charged.

Thanks guys.

I noticed 19% to 55% took 3 hours, that's +36%
And 55% to 90% took longer... Less, +35% and took 3.5 hours

So yeah even in AC it took longer after 80%.

There's no DC charger in Ecuador. Yet.

So everything is 6kW...

Oh side note, there are no public chargers. The only one is type 1... Outside the food market. Had to buy an adapter from AliExpress
View attachment 28892


Don't really plan to stay in those places longer than 0.5 - 1 Hour though...

And then in a mall, where I like going to the movies - there's a KIA charger that works ONLY for Kias... This feels like an ugly move.


Anyways, feels like 6H to go from 20 to 80 and run these 300km for 5-6 days is totally fine

You might find this video both informative and reassuring about NMC batteries.



Basically while the advice to operate the car between 20% and 80% on a day to day basis is sound as regards preserving the long term health of the battery - and by this we're talking LONG term - you shouldn't feel at all worried about going above or below these limits when you want to for long trips. It's not simply being at these high or low states of charge that can cause a problem, it's keeping the battery in that state for days at a time. Dr McTurk is even quite relaxed about leaving the car at 100% for a week or so, as long as you only do it occasionally and not all the time.

Any degradation caused by sitting at high or low SoC is a very slow, gradual process anyway, and would only lead to a bit of loss of range, not to any actual failure of the car. In addition, the experience of many owners who have been "mistreating" their batteries for years (frequent DC charging, often charging over 80%) is that they tend to hold up better than the pessimists suggest.

In effect, if you get home with less than 20% in the battery you're not going to leave it sitting like that anyway, are you? Even less so if you get to a public charger like that. So that's a nothing-burger. Just keep your maximum charge % set to 80% routinely, but then when you're charging up for a long journey when you need all that lovely range, change to 100%. You're going to be setting off and driving it down under 80% within a few hours anyway.

The bit about charging rate falling off as you approach 100% only applies to DC charging. On an AC charger the charge rate will stay constant right up to 100%.

The advantage of an NMC battery over LFP is that it is more energy dense so you have more range available. Yes, the LR car may seem to have only the same range as the SR for day to day driving, but you have that extra 50-60 miles to call on when you want it. You also have a significantly faster charging speed on DC, if you ever get the car to a DC charger that is! Whereas my SR takes 40 minutes to go from 10% to 80% on an ultra-rapid charger, the LR will be done in half that time. That is, if you have a charger capable of delivering over 150 kw.

 

[Ethernea]

You might find this video both informative and reassuring about NMC batteries.



Basically while the advice to operate the car between 20% and 80% on a day to day basis is sound as regards preserving the long term health of the battery - and by this we're talking LONG term - you shouldn't feel at all worried about going above or below these limits when you want to for long trips. It's not simply being at these high or low states of charge that can cause a problem, it's keeping the battery in that state for days at a time. Dr McTurk is even quite relaxed about leaving the car at 100% for a week or so, as long as you only do it occasionally and not all the time.

Any degradation caused by sitting at high or low SoC is a very slow, gradual process anyway, and would only lead to a bit of loss of range, not to any actual failure of the car. In addition, the experience of many owners who have been "mistreating" their batteries for years (frequent DC charging, often charging over 80%) is that they tend to hold up better than the pessimists suggest.

In effect, if you get home with less than 20% in the battery you're not going to leave it sitting like that anyway, are you? Even less so if you get to a public charger like that. So that's a nothing-burger. Just keep your maximum charge % set to 80% routinely, but then when you're charging up for a long journey when you need all that lovely range, change to 100%. You're going to be setting off and driving it down under 80% within a few hours anyway.

The bit about charging rate falling off as you approach 100% only applies to DC charging. On an AC charger the charge rate will stay constant right up to 100%.

The advantage of an NMC battery over LFP is that it is more energy dense so you have more range available. Yes, the LR car may seem to have only the same range as the SR for day to day driving, but you have that extra 50-60 miles to call on when you want it. You also have a significantly faster charging speed on DC, if you ever get the car to a DC charger that is! Whereas my SR takes 40 minutes to go from 10% to 80% on an ultra-rapid charger, the LR will be done in half that time. That is, if you have a charger capable of delivering over 150 kw.

Very informative.

Summary: NMC can be charged to 100% as needed only if you run it next day (dont leave it like that for months) and let it drop to 20% or 50%.

Never charge and stay between 80 - 100%

Its best to run 80% to 20% to get the most miles out of NMC batteries (and lasting the most years)

Nothing wrong if it drops lower than 20% as long as you charge as soon as you get home.

Got it. Noted. Doing this now.

 

[Rolfe]

The other little wrinkles are that the battery likes to balance its cells at 100% about once a month. So pick a day when you're likely to be driving it more than 50 miles in the next day or two, set the car to charge to 100% (on AC, obviously), and let it sit there till it has finished balancing. You can follow this in the app. The finishing time predicted is the time to 100%, but then after that the charging power will drop, sometimes to read zero, but the car is still showing as charging, and the finishing time will always read as the actual clock time at that moment. You know when the car is done because the app will change to "not charging" and there will be nothing showing under finishing time or charging power. The time taken seems to be quite variable, anything from 20 minutes to a couple of hours. The car will also balance when it's taken to a lower % charge so long as it's left plugged in, but it's good to give it that 100% every so often.

Wrinkle #2 is that both types of battery benefit from a "long charge" at least every six months. You do this by running the car down below 10% then charging it up to 100% (and balancing) in a single AC session. The car needs to see the full range of the battery from time to time so that it knows where the bottom of the well is, and it has to be charged up from there in one go because of the hysteresis curve and coulomb counting. The benefit of this is mainly to keep the GoM (the range estimate) honest. If it isn't doné the car may forget where the bottom of the well is, then one day when you drive it down there it sees the bottom and it may be a fair bit closer than the car thought it was. One minute you have ten miles left and the next minute it's reading empty. I think it's more important for the LFP, which has a very flat discharge curve, but it also applies to the NMC to some extent.

 

[Ethernea]

The other little wrinkles are that the battery likes to balance its cells at 100% about once a month. So pick a day when you're likely to be driving it more than 50 miles in the next day or two, set the car to charge to 100% (on AC, obviously), and let it sit there till it has finished balancing. You can follow this in the app. The finishing time predicted is the time to 100%, but then after that the charging power will drop, sometimes to read zero, but the car is still showing as charging, and the finishing time will always read as the actual clock time at that moment. You know when the car is done because the app will change to "not charging" and there will be nothing showing under finishing time or charging power. The time taken seems to be quite variable, anything from 20 minutes to a couple of hours. The car will also balance when it's taken to a lower % charge so long as it's left plugged in, but it's good to give it that 100% every so often.

Wrinkle #2 is that both types of battery benefit from a "long charge" at least every six months. You do this by running the car down below 10% then charging it up to 100% (and balancing) in a single AC session. The car needs to see the full range of the battery from time to time so that it knows where the bottom of the well is, and it has to be charged up from there in one go because of the hysteresis curve and coulomb counting. The benefit of this is mainly to keep the GoM (the range estimate) honest. If it isn't doné the car may forget where the bottom of the well is, then one day when you drive it down there it sees the bottom and it may be a fair bit closer than the car thought it was. One minute you have ten miles left and the next minute it's reading empty. I think it's more important for the LFP, which has a very flat discharge curve, but it also applies to the NMC to some extent.

"let it sit there till it has finished balancing"

Wait.. is this like... "The gas gun stops automatically. And you can still pour additional gas to top it out"

Similar to that?

Im confused. Is there a video that explains this behavior with illustrations?

I dont remember reading this in the mg4 manual... And obviously i care for the longest lifespan of this battery.

 

[Rolfe]

Not really. The battery reads full when the first cells are full, I think. But then the car goes round them all topping each one up or balancing the charge across them, so that all the cells are at the same voltage. It draws very little power while it's doing that. Think about filling a tray of ice cubes and just tilting it back and forwards or adding a little bit of extra water until all the compartments are at the same level.

The car does it automatically. It's just good to know that it does it so that you don't cut the power as soon as you see 100%, but rather leave the car to draw the small amount it wants until it's completely finished. Unless the power is cut for some reason (end of scheduled charging, or maybe the sun disappears, or you look at the app and say what's it doing, it's full, I'll just stop it now) it will just happen.

All you need to know is that once a month or so you should let the car go to 100% on an AC charger and not cut the power till it's finished doing its thing.

 

[Ethernea]

Not really. The battery reads full when the first cells are full, I think. But then the car goes round them all topping each one up or balancing the charge across them, so that all the cells are at the same voltage. It draws very little power while it's doing that. Think about filling a tray of ice cubes and just tilting it back and forwards or adding a little bit of extra water until all the compartments are at the same level.

The car does it automatically. It's just good to know that it does it so that you don't cut the power as soon as you see 100%, but rather leave the car to draw the small amount it wants until it's completely finished. Unless the power is cut for some reason (end of scheduled charging, or maybe the sun disappears, or you look at the app and say what's it doing, it's full, I'll just stop it now) it will just happen.

All you need to know is that once a month or so you should let the car go to 100% on an AC charger and not cut the power till it's finished doing its thing.

I don't have access to the app in this country and the dealership confirmed that. They plan to enable it but need some "homologation" supposedly...

So let me get this clear.

That ice cube tray analogy made me get it. This ONLY occurs when we let it go 100% and let it continue for a while?

Ive never seen it to 100%. I received it on 90% and 22km ODO... They drove it tk me so i dont wait another day

So it should go to 100% at least once and let it stay there for a while - to balance all the cells so the readings are more precise? Like that?

 

[Rolfe]

The app is convenient but not essential. You can perhaps see on the charger when it's balancing. But you don't really need to see it, all you need to do is not cut the power for long enough after the car has reached 100% so that you know it has done it. Best ask people with the LR battery what's the longest they've ever seen it take.

It will balance to some extent at lower states of charge if you've set a limit and you leave it connected for long enough once it's got there, but it's best to do the 100% balance every month or so.

However, it's not the end of the world if you're not rigorous about this. The main issue is that as the cells become more and more out of balance the car loses range, but as far as I know that can be regained by a few good balance charges.

All this advice is just good practice, good habits to get into. But it won't break anything if you depart from this routine when it suits you. The main thing is to drive your car and to enjoy driving it. To make the car your servant and not the other way round. These batteries are pretty robust and pretty long lasting whatever you do, and they're turning out to hold up better than I think even the manufacturers expected. You have the manufacturer's warranty against any unforeseen fault developing early (and it's a lot longer than anything you'll get on an ICE car), and the batteries that last the warranty period are likely to be good for the long haul.

Just relax and enjoy the car.

 

[Martinonline]

Let it charge until the green charging lights stop flashing and go out. The car has reached it's set charging limit (100% for LFP and as set in the car/app for NMC) and has balanced.

 

[Rolfe]

I never knew that. I never look at the charging lights. In fact they stopped working a month or two ago.

 

[tsedge]

I never knew that. I never look at the charging lights. In fact they stopped working a month or two ago.

This is a known problem with an easy fix - either disconnect and reconnect the 12V supply or there is a fuse in the driver's side fuse compartment (difficult access) which can be removed and reinserted.

Mine was sorted when the car went in for other fixes.

 

[Koomi]

I don't have access to the app in this country and the dealership confirmed that. They plan to enable it but need some "homologation" supposedly...

So let me get this clear.

That ice cube tray analogy made me get it. This ONLY occurs when we let it go 100% and let it continue for a while?

Ive never seen it to 100%. I received it on 90% and 22km ODO... They drove it tk me so i dont wait another day

So it should go to 100% at least once and let it stay there for a while - to balance all the cells so the readings are more precise? Like that?

That is exactly it!

Drive it between 20-80 if that works.
If you need to go lower, go lower than 20 (most people do not like letting their fuel drop below 80km before hitting a gas station)
If you know you are driving far the next day, go higher as the "long term storage" the battery is only unhappy if left for a long time (many days) at high charge.
If you have cheap electricity over night, use that when you can... even if you charge to 80+ each night before driving in the morning.
Once a month, let it charge to 100% overnight, and not worry about the charge state... the car will stop the supply once the ice tray has balanced... but with the points above, don't do this if you do not plan to drive for a few days