50% battery drop while parked

[Jennyt]

Hi, we picked up our new MG ZS Saturday. Monday my wife drove to work ~20 miles, she parked at work with 80% battery left, 7 hours later when she left work the battery was at 30% and by the time she got home it was 20%.
Is this normal? or is it because it's so new.

Did you find out the cause, im having exactly the same issues!

 

[Robt]

Did you find out the cause, im having exactly the same issues!

We think it was granny charging from new and never quite to 100% - it was literally days old when this happened. The battery never conditioned itself, sorry there's a word for it but I can't remeber - where you leave it charging at 100% for as long as it needs( a few hours I think) it only pulls ~300 watts while in this state but It's doing something that helps it work out the battery % better and should be done once a month. Since this one time we've had absolutely no trouble with it at all. We are now fast charging(7kw) at home.

 

[Jennyt]

We think it was granny charging from new and never quite to 100% - it was literally days old when this happened. The battery never conditioned itself, sorry there's a word for it but I can't remeber - where you leave it charging at 100% for as long as it needs( a few hours I think) it only pulls ~300 watts while in this state but It's doing something that helps it work out the battery % better and should be done once a month. Since this one time we've had absolutely no trouble with it at all. We are now fast charging(7kw) at home.

ive had the drop happen twice now seems to be when it gets to 100 miles left it drops to 80 without the car even being driven. i use the plug that was supplied to me as we have a charging port at home

 

[Robt]

ive had the drop happen twice now seems to be when it gets to 100 miles left it drops to 80 without the car even being driven. i use the plug that was supplied to me as we have a charging port at home

Does the battery % drop, or just the guessed range? The range is calculated from your previous drive. So if you drive home fast it may guess 100 miles left(if your previous drive was slow) then when you get back in the car it will guess your driving fast again and say you have 80 miles left - the % should be the same .

Or as others have said to me it is quite easy to lock the car and leave it on, ie. the AC or heating still running.

 

[Jennyt]

the battery percentage drops also.I havent turned any of those features on for them to be on

 

[Robt]

I would do the battery balancing as detailed here:

MG ZS EV charging FAQ

MG ZS EV charging FAQ This guide mainly applies to the 44kwh 1st generation MG ZS EV (Can apply to other cars but figures quoted might not be the same, as battery packs & charging rates maybe larger or hopefully not smaller) Charging categories: Charging speed can be defined into these three...

www.mgevs.com

"Once the car reaches 100%, the car will go into a mode called balancing. The ZS EV battery pack is made up of hundreds of smaller individual battery cells. Best way to describe it, you just filled up your ice cub tray with water from the tap very quickly. Most of the cubes are full (they are the individual battery cells) but a few are not. What you do now is with a very slow trickle from the tap, you top up each of the empty cubes until they are all level and full with each over. You can unplug if you want but it’s best to leave the car to balance if you can, it helps with battery health. When balancing, its using 300-500w of power per each hour. Balancing can take a while, either once the car reaches 8 hours or it’s perfectly balanced it will shut down, whichever is first. A misbalanced battery can take multiple full charges to get back to balance. The ZS EV will warn you if you need to do a balance charge, saying "Please Slow-Charge the Vechicle". Any AC will do this, but make sure you leave it once its got to 100% to do it's balance. How do I know it's balancing when I don't have a fancy smart EVSE, you may ask. Well the MG badge at the front will be solid on (not pulsing) when balancing. Once done, the badge will turn off.

What is the perfect EVSE for you? Click HERE to read another article about it."

 

[Jennyt]

i shall try this thank you, how do i check the battery preheat is turned off and the climate control also just to make sure its not either of those?

 

[Lovemyev]

We think it was granny charging from new and never quite to 100% - it was literally days old when this happened. The battery never conditioned itself, sorry there's a word for it but I can't remeber - where you leave it charging at 100% for as long as it needs( a few hours I think) it only pulls ~300 watts while in this state but It's doing something that helps it work out the battery % better and should be done once a month. Since this one time we've had absolutely no trouble with it at all. We are now fast charging(7kw) at home.

Performing a battery “Balance” at the end of the charging cycle, can be done from any A/C supply, either a 7 kw wall box at home or at a public place.
But I would not recommend this option and is blocks the EV space for others.
Balancing the battery from a A/C “Granny” unit is the very same thing.
But you can’t balance the pack from. D/C rapid unit !.

 

[Jennyt]

I would do the battery balancing as detailed here:

MG ZS EV charging FAQ

MG ZS EV charging FAQ This guide mainly applies to the 44kwh 1st generation MG ZS EV (Can apply to other cars but figures quoted might not be the same, as battery packs & charging rates maybe larger or hopefully not smaller) Charging categories: Charging speed can be defined into these three...

www.mgevs.com

"Once the car reaches 100%, the car will go into a mode called balancing. The ZS EV battery pack is made up of hundreds of smaller individual battery cells. Best way to describe it, you just filled up your ice cub tray with water from the tap very quickly. Most of the cubes are full (they are the individual battery cells) but a few are not. What you do now is with a very slow trickle from the tap, you top up each of the empty cubes until they are all level and full with each over. You can unplug if you want but it’s best to leave the car to balance if you can, it helps with battery health. When balancing, its using 300-500w of power per each hour. Balancing can take a while, either once the car reaches 8 hours or it’s perfectly balanced it will shut down, whichever is first. A misbalanced battery can take multiple full charges to get back to balance. The ZS EV will warn you if you need to do a balance charge, saying "Please Slow-Charge the Vechicle". Any AC will do this, but make sure you leave it once its got to 100% to do it's balance. How do I know it's balancing when I don't have a fancy smart EVSE, you may ask. Well the MG badge at the front will be solid on (not pulsing) when balancing. Once done, the badge will turn off.

What is the perfect EVSE for you? Click HERE to read another article about it."

i shall try this thank you, how do i check the battery preheat is turned off and the climate control also just to make sure its not either of those?

 

[Robt]

i shall try this thank you, how do i check the battery preheat is turned off and the climate control also just to make sure its not either of those?

I honestly have no idea how to turn the pre-heat on or off, never found it and all the guides I've watched don't match what I see in my car.
to switch climate control off just make sure you've pressed the stop button before you lock the car.

 

[Lovemyev]

We must be talking face lift model here of course ???.
I was of the opinion that if you select preheat of the HV battery, it would automatically default back to the OFF setting, the next time the car is powered up ?.
Preheat / precooling will be set in the App or the head unit of the car.

 

[Robt]

We must be talking face lift model here of course ???.
I was of the opinion that if you select preheat of the HV battery, it would automatically default back to the OFF setting, the next time the car is powered up ?.
Preheat / precooling will be set in the App or the head unit of the car.

yeah I'm in a 2022 once, there's no pre-heating in the app. There's scheduling for overnight charging but no pre-heating.

 

[Jennyt]

yeah I'm in a 2022 once, there's no pre-heating in the app. There's scheduling for overnight charging but no pre-heating.

so im guessing Preheat battery / preconditioning doesn't exist? my car only seems to drop when it gets to 100 down to 80% so there must be something that im doing wrong​

 

[EV AL]

Some thing that I noticed on our face lift model only today.
If you have the radio playing and then shut down the car, the radio continues to play and the info unit is still active.
I got out of the car, went around to the boot, got out our shopping bags ( super market run ) closed the doors and I could still see the info unit was still running !.
Pressed the “Lock” button on the fob, instantly the info unit closed down.
I have no idea if it has a “timed out” function that would close it down, if you left it alone ?.
I am sure it must have ????.
On the original Gen1 model, the info unit would close down as soon as you shut down the car.
We live and learn I guess !.
Quick update :-
Just tried it outside the school and the info unit closes down automatically after exactly 10 minutes !.

@Lovemyev ….same thing here, was a bit confused when switched car off and radio stayed on I thought it was a fault compared to Gen 1, but it is obviously normal.
save me visit back to dealer.

 

[Lovemyev]

There is a feature in the head unit that WILL allow you to “Pre-Heat” the HV battery before jumping onto a a rapid charger.
You can use this pre-heat facility to increase the charging speed.
HV batteries charge quicker when they are at an ideal temperature.
It uses a fair bit of energy from the HV battery itself, so you have to judge it’s use carefully !.
I have never used it myself, just to be clear.
My understanding is, that you can’t leave it on by mistake !.
If you use it, then once the car is powered down, it returns back to the default setting of OFF !.

 

[Robt]

There is a feature in the head unit that WILL allow you to “Pre-Heat” the HV battery before jumping onto a a rapid charger.
You can use this pre-heat facility to increase the charging speed.
HV batteries charge quicker when they are at an ideal temperature.
It uses a fair bit of energy from the HV battery itself, so you have to judge it’s use carefully !.
I have never used it myself, just to be clear.
My understanding is, that you can’t leave it on by mistake !.
If you use it, then once the car is powered down, it returns back to the default setting of OFF !.

Yeah I'm aware of what it does, but I can't find it - all the youtube videos I've watched look nothing like mine.

 

[Lovemyev]

@Lovemyev ….same thing here, was a bit confused when switched car off and radio stayed on I thought it was a fault compared to Gen 1, but it is obviously normal.
save me visit back to dealer.

You are very welcome !.
It’s a bit of a strange set up really ?.
I can’t get my head around why they set it up this way really ?.
The good news is, that when you lock the car, it closes it down and it will also powers down after about ten minutes, if you are sitting in the car with the radio running.
Have you noticed this one ?.
Open the car in the morning, reach in and lightly press the front screen of the info unit.
You will hear the unit respond with a soft bleeping sound.
So, the front screen is still semi active when the car has been powered down over night ?.
The power drain must be minimum, but there must be one for the screen to react ???.
Have you jumped out of the car yet, without powering it completely down ? .
I have done this a couple of times !.
Not pressed the start / stop correctly, or just forgot !.
Then I can be seen shaking my head wondering why the horn sounds, when I try to lock the car with the fob !.
Old age I guess .

 

[Witeduke]

Some thing that I noticed on our face lift model only today.
If you have the radio playing and then shut down the car, the radio continues to play and the info unit is still active.
I got out of the car, went around to the boot, got out our shopping bags ( super market run ) closed the doors and I could still see the info unit was still running !.
Pressed the “Lock” button on the fob, instantly the info unit closed down.
I have no idea if it has a “timed out” function that would close it down, if you left it alone ?.
I am sure it must have ????.
On the original Gen1 model, the info unit would close down as soon as you shut down the car.
We live and learn I guess !.
Quick update :-
Just tried it outside the school and the info unit closes down automatically after exactly 10 minutes !.

To turn radio off hold the home menu tab under the screen for 5 seconds !

 

[EV AL]

You are very welcome !.
It’s a bit of a strange set up really ?.
I can’t get my head around why they set it up this way really ?.
The good news is, that when you lock the car, it closes it down and it will also powers down after about ten minutes, if you are sitting in the car with the radio running.
Have you noticed this one ?.
Open the car in the morning, reach in and lightly press the front screen of the info unit.
You will hear the unit respond with a soft bleeping sound.
So, the front screen is still semi active when the car has been powered down over night ?.
The power drain must be minimum, but there must be one for the screen to react ???.
Have you jumped out of the car yet, without powering it completely down ? .
I have done this a couple of times !.
Not pressed the start / stop correctly, or just forgot !.
Then I can be seen shaking my head wondering why the horn sounds, when I try to lock the car with the fob !.
Old age I guess .

@Lovemyev ….cheers, had the horn sounding several times, also find it annoying that you can only see the total mileage by using steering wheel button < > to find it amongst the accumulated figures

 

[hmadsen]

Yeah I'm aware of what it does, but I can't find it - all the youtube videos I've watched look nothing like mine.

Easy

Go to the battery settings menu (Either by pressing that portion of the screen or flipping the battery switch above the gear selector)

When you have the image of your car, where you can set how full you want the battery and so on, in the right hand corner in the top, there is a button called something like "charge settings".

Press that button and there is the toggle switch for the preheating of the battery