Charge won't stop at 80 percent

[Cornish Paul]

Due to a rubbish home supplier, I am currently restricted to the Granny charger. I have this set to charge from midnight to 05:00 (the cheap rate of 9.4p/KWh) and charge to 100% BUT I know 5 hours gets me about 20% of the charge so I simply wait until I am below 60% to plug in. If I am at 40% I simply charge two nights running. I am sure a home charger will have a measurable charge rate as well. I have never had an issue this way.

 

[Vingnut]

Well have fiddeld with the 3 apps involved in smart home charging in my house. Very unstable but it seems that I are now using the powercompany app to controll my charger and the car is controlling max charge (will not bet on it).

When doing this I screen shoteted the issue of not updating charge time and so one in the ismart app, to note here is that when my app shows 0,0bar tyrepressure it has not connected correct. Solution was to uppdate and update (5 times actually) the ismart app to it to read the tyrepreassure, then it also showed new calculation in the charging menue.

Note that km/miles is shown as as actual remaiming not what it wil be after charging. Hope that helps someone.

If the charging stops at 70 percent involving smart charging remain to be seen but I wil know very son.

 

[wandle MG4 trophy]

My Trophy has been into the dealer twice now for various things including iSmart spontaneously changing my overnight charge target from 80% to 100%. The problem continues.

The other day it went to 100%. As I was away it was impossible for me to use the car to deplete the battery so it sat at 100% for 36 hours. On return I took it for a needless drive but had to return home at 85%. Given the recommendation to keep the Trophy battery between 80 and 100% do you think the battery has been damaged?

 

[Ian Key]

My Trophy has been into the dealer twice now for various things including iSmart spontaneously changing my overnight charge target from 80% to 100%. The problem continues.

The other day it went to 100%. As I was away it was impossible for me to use the car to deplete the battery so it sat at 100% for 36 hours. On return I took it for a needless drive but had to return home at 85%. Given the recommendation to keep the Trophy battery between 80 and 100% do you think the battery has been damaged?

Not if it was a one off. But I have noticed the iSmart app has a tendency to change from 80% to 100% charge. I now check it before every home charge.

 

[Vingnut]

My Trophy has been into the dealer twice now for various things including iSmart spontaneously changing my overnight charge target from 80% to 100%. The problem continues.

The other day it went to 100%. As I was away it was impossible for me to use the car to deplete the battery so it sat at 100% for 36 hours. On return I took it for a needless drive but had to return home at 85%. Given the recommendation to keep the Trophy battery between 80 and 100% do you think the battery has been damaged?

Not noticable as a one off or two, it's the longer it's sitts on a high charge and the acumulation of these instances over time that count to more than normal degradation. Do not worry over the 85% it' way better than sitting at 100%.

Always chek the ismart app before every home charge, as it does the 80% changing to 100% "trick" ? from time to time.

Back to last night test of home ac smart charging with 80% cut off.

As I have mentioned I had to resort to charging my car with the car starting and stopping the charge with the cars inbuilt charge planner to get it to stop at 80% (LR), so called dum charging as it made me think it was impossible to let my powercompany controll the charger and start/stop the charging when prices is low and not to exceed 80% soc (The cars charge planner is acsessable in the infotainment screen and the ismart app).

Well to put it short (ha) it was a succsess.

The process was possible when setting the charge plan to start before I plug in the charger (because of problems getting the powercompany app to recognice the car beeing connected) and after it should be finnished, in my case 1800 to 0600. Then get the powercompany app to connect and controll the charger to get it to charge when the price was lowest between 0200 and 0500 last night (Norway has spot hourly rates).

To be honnest the prosess was very fiddly caused by the ismart to constantly changing the planner back to my normal 2200-0600 scedule (mybe because it was all done in the app) and the powercompany app not recognicing that the car was connected.

Everything was further complicated by the fact that opening the apps to chek if everyting was set reset the planner or disconected the powercompany app (Tibber) from the car.

Workaround was to not go to far in to the powercompany app ( Tibber) and relying on the charger be light up green in the Tibber app and not go in to the charger tab, and when this seemed ok chek the ismart app to see if the planner was stil ok and then leave it all alone.

It all seem a bit complicated but in reality it's all about finding out how to avoid the car to revert to previus settings and make the car, charger and apps talking to eachothers. As Rolfe says, "Finding the workarunds and it's not realy a problem." ?

Now I just have to use some of the "juice" so I can continue the test.


P.s. to just stop the charging at 80% it's just to set the cars charge planner to charge when you want it to and set max soc to your liking (normaly 80%), start the charger and let it be controlled by the car.

Hope this wil help those who have problems stopping ac charge of their LR at 80%.

 

[Rolfe]

This video was posted in another thread. The guy really seems to know what he's talking about. He's relatively reassuring about NMC batteries at 100% for limited periods, he seems more to be talking about not letting them sit like that for days.

 

[Filban]

As an up-date - scheduled charging and battery percent limit setting do not work for me. Excite model (same as UK SE) but with LR battery. Brought it back to dealer for health check and review (160 mile round trip), results inconclusive. Car got clean bill of health but they're not sure why charging won't stop at 80% and need to consult with MG headquarters. Been just over a week and not heard anything back from them yet.
There was a suggestion that as it's the low spec model with LR battery - the infotainment software is caught between the low spec and high spec models so may be an issue unique to that 'flavour'. I was the first report they had of this issue but expect it will arise more as more cars are delivered.

 

[Rolfe]

Haven't heard anyone here with the SE LR saying they can't get the charge to stop at 80%, ever. There have been some complaints about the target resetting itself spontaneously and the car charging to 100% because of that, but not as a permanent thing.

You're right though, the SR cars absolutely ignore any attempt to set the app to stop a charge early, because the LFP battery is fine about being fully charged and needs to balance at 100% on an AC charger as often as possible. Maybe your software thinks your car is an SR?

 

[PeterD]

Hello all,

I have the mg4 SE (LiFe basic spec) model.

Found the app keeps locking my charge% to 100%, I loose the slider and cannot change the percent I wish to charge too. I have to unbind from the car and rebind so I get the toggle back.

After my most recent attempt the battery now just continually charges to 100% if I don't keep an eye on it / time it right.

I think this is a software issue personally, but not sure what to do on the next steps. I have logged as a fault with the play store contact, the garage does not know what to do and other than waste a day trying to demonstrate... I don't know what to do. Any suggestions?

 

[Rolfe]

It's doing what it's supposed to do, but MG using the same software for LFP and NMC batteries is confusing you.

The LFP battery should be allowed to charge to 100% every time. There is no benefit in stopping it early. It likes to balance frequently and it has to go to 100% (on an AC charger) to do that. You will not do your battery any significant harm by doing this, its chemistry is very different from the NMC batteries to which the 20% to 80% advice applies.

Once upon a time everyone had the same capabilities in the app, and LFP owners could stop the charge early. However MG removed this ability from the LFP cars some months ago (before I got my car, because I was confused by this too) so that they always aim for 100%. It's best for the battery to let that happen.

 

[siteguru]

I was one of the early adopters who saw the charge limit slider in the app, and was one of the first to report it going missing. I believe that MG have this option configured on their server for the car bound to the account, so when it knows it's an SR it sets a flag in the app to remove the slider.

The reasons for no slider are accurately covered above by @Rolfe

 

[Rolfe]

I remember it was you who explained it to me when I woke up the morning after I got my car and wondered why it had charged all the way to 100% when I thought I was doing the right thing by setting the slider at 80%. (My dealer did say "Just charge it up to 100%" when I asked about the 80% thing, but as he hadn't been clear about this being a specific difference for the LFP battery I was still confused at that stage.)

There are people still running around telling LFP owners that they too will wreck their batteries if they take them to 100%. Such advice is scaremongering even for the NMC, and it's not appropriate at all for the LFP. I've been listening to Euan McTurk and I now get it. I love my LFP battery.