80% or 100%

[PhilT]

I’ve contacted Ohme as I have an Ohme charger at home. I currently charge up to 100% on Octupus intelligent.My question/ is it ok to keep charging to 100%? If not how do you set it to 80%. I think Ohme have said they can’t control it but someone said set it on the infotainment screen. How and where please ?

 

[Deleted member 10041]

What car do you has SR or lr

 

[PhilT]

SR

 

[tkmaxx5]

I’ve contacted Ohme as I have an Ohme charger at home. I currently charge up to 100% on Octupus intelligent.My question/ is it ok to keep charging to 100%? If not how do you set it to 80%. I think Ohme have said they can’t control it but someone said set it on the infotainment screen. How and where please ?

You should use Ohme to add the amount of charge you want. So if you want to get to 80% and you are at 30% you need to tell the Ohme app to add 50%

 

[Deleted member 10041]

SR

The SR battery chemistry needs charged to 100% doesn't like 80, you also need to do a balance charge once a week (leave it plugged in and charging even though it's at 100%) it then balances all the cells and helps with battery health

 

[Deleted member 13624]

I’ve contacted Ohme as I have an Ohme charger at home. I currently charge up to 100% on Octupus intelligent.My question/ is it ok to keep charging to 100%? If not how do you set it to 80%. I think Ohme have said they can’t control it but someone said set it on the infotainment screen. How and where please ?

For clarity, the standard range battery doesn't have the ability to set the charge cut off on the vehicle because the battery tech used is safe to charge to 100%

Once you get to 100% the car will balance the cells, it will happen at the end of the charge.

My suggestion would be to charge once a week to 100% or when needed.

 

[Rolfe]

I have the SR and that's what I do. Whenever the charge is low enough that I don't feel comfortable leaving it like that (in case of unexpected events), I put it up to 100%. I either use the granny charger for all of it, or the rapid charger at the end of my street to get to over 80%, then home and on to the granny. It always putters around at about 20 watts for half an hour after reaching 100% to balance.

That tends to be about once a week, but if it's more than that I don't worry about it, I recharge anyway. What I don't do is to take it up to less than 100% and then start driving it again (unless I'm on a long journey, obviously), because I don't think the battery likes that. I always go to 100% and balance.

It seems to be necessary to get the GOM to work reasonably well. If it hasn't been allowed to balance the projected range apparently goes absolutely doolally.

MG have deliberately removed the function from the app to stop at 80% for the SR and they didn't do that for fun. It's too easy to hear all the exhortations aimed at people with LR batteries about not going to 100% too often and certainly not letting the car sit at that SoC for more than overnight, and think you should be doing that with an SR, but that's wrong.

 

[PhilT]

Brilliant replies. So succinct and reassuring. Many thanks

 

[Lee Morris]

So is is best to charge the Long Range models to 80% most of the time and only up to 100% for long drives?

 

[Diggsy]

So is is best to charge the Long Range models to 80% most of the time and only up to 100% for long drives?

Yes

 

[Lee Morris]

Yes

Thanks for clarifying will it harm the battery if I'm doing most of my charging with the granny lead?

 

[Diggsy]

Thanks for clarifying will it harm the battery if I'm doing most of my charging with the granny lead?

Nope, not at all.

 

[Deleted member 10041]

Thanks for clarifying will it harm the battery if I'm doing most of my charging with the granny lead?

Won't harm it at all, just make sure your set up for using the granny is safe and tested, in certain circumstances granny leads can overheat.

The sweet spot for the long range battery is between 20-80% that's the best for battery health. If you are going on a longer journey then charge to 100% but it doesn't like to sit like that for a prolonged period.
You can obviously take the battery below 20% also.

You also need to charge the LR to 100% once a month if you've not already done it, to balance the battery

 

[MartinSEsr]

I have the SR and that's what I do. Whenever the charge is low enough that I don't feel comfortable leaving it like that (in case of unexpected events), I put it up to 100%. I either use the granny charger for all of it, or the rapid charger at the end of my street to get to over 80%, then home and on to the granny. It always putters around at about 20 watts for half an hour after reaching 100% to balance.

That tends to be about once a week, but if it's more than that I don't worry about it, I recharge anyway. What I don't do is to take it up to less than 100% and then start driving it again (unless I'm on a long journey, obviously), because I don't think the battery likes that. I always go to 100% and balance.

It seems to be necessary to get the GOM to work reasonably well. If it hasn't been allowed to balance the projected range apparently goes absolutely doolally.

MG have deliberately removed the function from the app to stop at 80% for the SR and they didn't do that for fun. It's too easy to hear all the exhortations aimed at people with LR batteries about not going to 100% too often and certainly not letting the car sit at that SoC for more than overnight, and think you should be doing that with an SR, but that's wrong.

That's very clear and I agree.

However I was leaving my SR on the drive for 18 days recently, so I purpousfully ran it down to 70% before leaving it. I wouldn't want to leave even the SR at 100% for so long unused.

NB I got back and the main battery was at the same %, and the 12v battery was fine for unlocking etc. Though the ismart app lost connection after about 24h as the car went into deep sleep mode. When I got home, a unlock/lock with the fob woke it up and the 12v was at 12.3v.

 

[Rolfe]

That's very reassuring as I'll have to leave mine in an airport car park for about that length of time in September. (Well, I hope that happens, we're going to Rhodes!) Even if I start at full I'll be down under 75% by the time I get to the airport.

I thought I read somewhere that the SR should be stored with a full battery, but I don't remember where I read it, and it doesn't make sense. Surely for a prolonged period when you're certain you don't need the car, less than 80% would be better. But for a few days I don't think it matters.

Sometimes it's difficult to know whether to charge if you don't have anything planned, but don't want to leave the car sitting with only a short range in it in case something comes up unexpectedly. I tend to just do it, because something usually does come up, and in any case a few days at 100% isn't supposed to do the SR much harm.

 

[Vingnut]

To charge LR/Trophy to 80% (or another % value) one have to use the planed charging (in the charging menu in app or infotainment screen).

 

[Rolfe]

Doesn't work in the SR. It charges to 100% regardless. I think MG is trying to tell SR owners something!

 

[Museruk]

I am new to EV's and collected an MG4 LR Trophy in mid-June '23.
I am currently just using the supplied Granny charger, but plan to purchase an Ohme 7kW charger soon.
I am keen to keep the battery as healthy as possible i.e. minimise the inevitable charge deterioration with time (as I am sure most owners will wish to do).
However, I am really confused about the advisable maximum charge level when charging at home on a 'slow' charger (either Granny or 7kW).
Reading this thread and also elsewhere regarding the Li-NMC 64kWh battery, I also gather that this battery needs ideally to be kept charged to 80% max. and ideally be kept at between 50% and 80%, except if on a long journey, when obviously it will be necessary to charge to 100% shortly before the trip.
However in the latest MG4 User manual on page 295 under the heading: 'Precautions and restricted conditions for use of the battery', the first point stated is:

When using the vehicle on a daily basis, it is recommended to fully charge it at least once a week, which is conducive to the health maintenance of the high-voltage battery pack; every 3 months to half a year, a low-power (less than 10% or I grid) full charged is performed.

I have queried this more than once with the MG main dealer (Stoneacre, Derby) and they insist that it is recommended to charge regularly to 100% provided that you use a slow i.e. <11kW charger.

Even more strange is that on the MG UK website - MG4 page, then scroll to the bottom of that page and select the 'How to charge an electric car at home' article, then within that document also scroll to the bottom and select the supporting article: 'A guide to electric car battery life', it states within that article:
'There are several tips that you can use to try and increase your electric car battery life:
- Charge the electric car battery between 20%-80% - The lifespan of the battery pack often depends on how much it’s charged. You can extend the life of the batteries by only charging them between 20% and 80% and trying not to let them drop below 50% too often. Going beyond these limits can increase the rate that the battery deteriorates over time.
- Avoid overcharging - Overcharging can cause chemical changes inside the battery itself, which again could negatively affect how efficiently it can store energy. Ultimately, you are looking to reduce the number of charging cycles that your battery goes through in its lifetime.'
So now we have completely opposite statements from MG regarding charging of Lithium ion batteries - unless this second instruction is aimed at Ultra high charge rate DC chargers?
As stated, I have queried this and get the reply from everyone I have spoken to at the dealer: they all reply that it is perfectly safe to charge to 100% on a regular basis (as stated in the MG4 manual) provided of course you either use the Granny charger or a 7kW charger.
Apologies for the long post - but perhaps you can see my confusion!
I should mention that the MG4 user manual is common to all variants of this car - which in itself is suspicious given the 2 completely different battery chemistry's of the SR and LR / Trophy batteries (Lithium LFP and NMC respectively). The stock answer I get is that the battery has been proven to over 350,000 miles with only circa 4% drop in capacity whilst following the 100% regular charging routine!
Can anyone offer clarification on this issue?

 

[bowfer]

100% every time, in every EV I’ve owned.
FWIW my BIL has a taxi MG5, charges to 100% every time (slow charging though, not rapid so often)
70000 miles in 18 months and 95% health.
On the taxi forum he frequents there’s a 5 with 300000 miles and still over 90% health.
These guys don’t do 80% charging, they can’t afford to have ‘missing’ range.

 

[siteguru]

Charging the NMC battery to 100% every time is not really a problem ... provided that you're going to start drawing down from that charge right away (e.g. next morning). The issue comes with charging to 100% and then leaving it for a couple or more days just sitting there.