First time rapid charge on my MG ZS EV

[Headgas1]

Hi all firstly I am a total newbie and having only owned my car for a few days I went and did a rapid charge as the orange recharge battery was lit and when charging started it showed 21% after approx 40 mins it stopped and I got back into the car the HV battery power gauge showed 100% full and the gom showed 170 miles I am confused and worried as I thought it would stop charging at 80% ?? Can anyone help with what happened ? I couldn’t see on charger or car what was happening when charging !!!!!!!

 

[AnonymouseDriva]

Hi. - it'll charge until it's full. It just slows down considerably after 80%, so in most people's opinion it's not worth waiting for the last 20% to go in.

 

[Headgas1]

Hi. - it'll charge until it's full. It just slows down considerably after 80%, so in most people's opinion it's not worth waiting for the last 20% to go in.

Hi thanks for fast reply is it ok that it went to 100% I thought it automatically stopped at 80% and it went from 20% to 100% in only 40min ?

 

[AnonymouseDriva]

Hi thanks for fast reply is it ok that it went to 100% I thought it automatically stopped at 80% and it went from 20% to 100% in only 40min ?

That does seem a bit speedy, but then my point of reference is a 5LR and I've only ever rapid charged it to 'give it a go' for 10 mins. They definitely don't stop at 80% though.

It seems that rapid charge times are mostly quoted to 80%. This is because the car will slow the charging down considerably after that point to protect the battery / prevent overheating / other technical reasons that I won't pretend to know.

The assumption therefore is that if you're stood waiting for the car to carry on with your journey, it's pointless waiting for the last 20% to trickle it. You might as well get on your way and stop again later for another (faster) top up. If you're still connected though it'll just carry on until you're done.

Also, some of the posts I've seen on here about the ZS Battery Management suggest that it has been given larger 'buffer zones' and as a result actually fast-charges up to (or maybe slightly over) 'displayed' 90%, but hopefully another ZS owner will clarify that in case I have mis-read or misunderstood.

Saying that - do you even get a % on the ZS? I thought it was just a range, so you might be just charged enough to light the last bar (so, at a guess - in the 90-100% range). I think someone posted the proper breakdown of the gauge on the forum previously.

 

[Headgas1]

That does seem a bit speedy, but then my point of reference is a 5LR and I've only ever rapid charged it to 'give it a go' for 10 mins. They definitely don't stop at 80% though.

It seems that rapid charge times are mostly quoted to 80%. This is because the car will slow the charging down considerably after that point to protect the battery / prevent overheating / other technical reasons that I won't pretend to know.

The assumption therefore is that if you're stood waiting for the car to carry on with your journey, it's pointless waiting for the last 20% to trickle it. You might as well get on your way and stop again later for another (faster) top up. If you're still connected though it'll just carry on until you're done.

Also, some of the posts I've seen on here about the ZS Battery Management suggest that it has been given larger 'buffer zones' and as a result actually fast-charges up to (or maybe slightly over) 'displayed' 90%, but hopefully another ZS owner will clarify that in case I have mis-read or misunderstood.

Saying that - do you even get a % on the ZS? I thought it was just a range, so you might be just charged enough to light the last bar (so, at a guess - in the 90-100% range). I think someone posted the proper breakdown of the gauge on the forum previously.

Yep no % on my ZS just going off the HV gauge showing full and the GOM of 170 miles it’s a bit puzzling it showed the car charging at the start on the instrument panel but it disappeared ? Does anyone know how to get it back during the charging process?

 

[AnonymouseDriva]

ZS manual, P150 (rapid charging ) and 152 (slow charging) both have the same note:

Not sure what unlocking the car does to the rapid charge for you though.

 

[Headgas1]

Ok noted thanks for your help & advice buddy I did open the car during charge nothing happened

 

[Lovemyev]

If you want to do a quick check / view your % when on charge, on A/C.
If you keep the keys out of range from the car, the just press the button on the drivers door and it will display the range / % in the dash panel, which can be seen though the drivers window.
If you have the keys in your pocket, when you press the button, it will unlock the car !.
On D/C rapids, you can open the door and it will keep on charging.
There is an update, that WILL allow you too charge on A/C and have the doors unlocked.

 

[Headgas1]

ZS manual, P150 (rapid charging ) and 152 (slow charging) both have the same note:
View attachment 4855

Not sure what unlocking the car does to the rapid charge for you though.

Thanks buddy will give it a try nice tip ???

 

[HansG]

I've only tried rapid charging mine once and was positively surprised by the speed
Around 60~ kw from 20-80%
At 85% Still got 36kw
At 93% 26kw
At 95% it started to throttle a bit and delivered 10,5kw

So i guess your 40 mins can be done.

If you want to see how many kw you get - start the car and check voltage & amps while charging.

Voltage*Amps and you can see how many W the charger delivers.

Example:
412*125 = 51500 w, and 51,5 kw

 

[Headgas1]

If you want to do a quick check / view your % when on charge, on A/C.
If you keep the keys out of range from the car, the just press the button on the drivers door and it will display the range / % in the dash panel, which can be seen though the drivers window.
If you have the keys in your pocket, when you press the button, it will unlock the car !.
On D/C rapids, you can open the door and it will keep on charging.
There is an update, that WILL allow you too charge on A/C and have the doors unlocked

I've only tried rapid charging mine once and was positively surprised by the speed
Around 60~ kw from 20-80%
At 85% Still got 36kw
At 93% 26kw
At 95% it started to throttle a bit and delivered 10,5kw

So i guess your 40 mins can be done.

If you want to see how many kw you get - start the car and check voltage & amps while charging.

Voltage*Amps and you can see how many W the charger delivers.

Example:
412*125 = 51500 w, and 51,5 kw

Hi thanks just checked account and it was 45 mins just worried me cos I was sure it stopped at 80% but the answers from u guys has reassured me ??????

 

[JodyS21]

I've not DC charged much (in single figures), but every time I have, the chargers themselves all show the cars % and the power kW being supplied and the accumulated kWh supplied.
It's not ideal that it's not simple to always see it on the cars dash, but it's always there on the chargers screen.

I'm a bit surprised that you managed to DC charge from 21% to 100% in 45 mins (due to the slowing down towards the end). I suspect that it wasn't actually charged to 100% but was charged enough to light up all the bars on the unuseful HV battery gauge.

 

[Headgas1]

I've not DC charged much (in single figures), but every time I have, the chargers themselves all show the cars % and the power kW being supplied and the accumulated kWh supplied.
It's not ideal that it's not simple to always see it on the cars dash, but it's always there on the chargers screen.

I'm a bit surprised that you managed to DC charge from 21% to 100% in 45 mins (due to the slowing down towards the end). I suspect that it wasn't actually charged to 100% but was charged enough to light up all the bars on the unuseful HV battery gauge.

My wife pressed something and it disappeared off the charger screen also there’s 3 charging points on same charger we can’t all see our own charges can we ? Anyway what I can tell u for sure is we received. 31.2 kw in 45mins HV gauge full gom 170 miles !!!!!!

 

[Dave53]

Yep no % on my ZS just going off the HV gauge showing full and the GOM of 170 miles it’s a bit puzzling it showed the car charging at the start on the instrument panel but it disappeared? Does anyone know how to get it back during the charging process?

Switch the car on then off when rapid charging, DONT'T put your foot on the brake, just press it twice, when you then switch it off it will show you the percentage for about 30 seconds and disappear again go through the same process to see how the percentage has increased if you are AC charging opening the door and closing it shows the percentage for 30 seconds also.

 

[Dave53]

I've not DC charged much (in single figures), but every time I have, the chargers themselves all show the cars % and the power kW being supplied and the accumulated kWh supplied.
It's not ideal that it's not simple to always see it on the cars dash, but it's always there on the chargers screen.

I'm a bit surprised that you managed to DC charge from 21% to 100% in 45 mins (due to the slowing down towards the end). I suspect that it wasn't actually charged to 100% but was charged enough to light up all the bars on the unuseful HV battery gauge.

The new HV battery update allows for faster charging on DC as the upper buffer is bigger now, I suspect if its a new car this has already been applied to the car??

 

[Dave53]

0

My wife pressed something and it disappeared off the charger screen also there’s 3 charging points on same charger we can’t all see our own charges can we ? Anyway what I can tell u for sure is we received. 31.2 kw in 45mins HV gauge full gom 170 miles !!!!!!

if you are on a rapid charger and it has the 3 different types of cables on it then only one car can charge on it at a time using the correct cable for their particular car, on this type of unit normally when you repress the screen it comes back up with the charge rate on it, I know on the fast chargers where it has 2 sockets it pulses between the 2 sockets showing how much it has input to the car

 

[JodyS21]

My wife pressed something and it disappeared off the charger screen also there’s 3 charging points on same charger we can’t all see our own charges can we ? Anyway what I can tell u for sure is we received. 31.2 kw in 45mins HV gauge full gom 170 miles !!!!!!

You got a 73% charge then (31.2/42.5).
Plus your initial 21%, you ended up with roughly 94%

 

[Headgas1]

0

if you are on a rapid charger and it has the 3 different types of cables on it then only one car can charge on it at a time using the correct cable for their particular car, on this type of unit normally when you repress the screen it comes back up with the charge rate on it, I know on the fast chargers where it has 2 sockets it pulses between the 2 sockets showing how much it has input to the car

I see ok thanks didn’t realise first time ???

 

[Deleted member 2439]

I've only tried rapid charging mine once and was positively surprised by the speed
Around 60~ kw from 20-80%
At 85% Still got 36kw
At 93% 26kw
At 95% it started to throttle a bit and delivered 10,5kw

So i guess your 40 mins can be done.

If you want to see how many kw you get - start the car and check voltage & amps while charging.

Voltage*Amps and you can see how many W the charger delivers.

Example:
412*125 = 51500 w, and 51,5 kw

This is only a rough and ready measure as the charger displayed rate is AC incoming power to the vehicle. The rates displayed on the vehicle are DC volts and amps into the battery. Your logic only works if the charger is 100% efficient - which it isn’t. The efficiency is high, well up in the high 90s % + area, but it’s not 100%.

The “lost” energy goes in the resistance of the cables and overcoming the saturation voltage drops in the numerous semiconductor devices in the vehicles charger. The vast majority will be lost as heat, but a small amount as sound as the high currents involved make the wound devices vibrate ever so slightly. If charging in hot weather it’s possible that fans will come on to cool the batteries - that takes power as well.

As a rule of thumb I’d suggest that your calculation is about 95% correct - with the difference being for the reasons given.

 

[JodyS21]

This is only a rough and ready measure as the charger displayed rate is AC incoming power to the vehicle. The rates displayed on the vehicle are DC volts and amps into the battery. Your logic only works if the charger is 100% efficient - which it isn’t. The efficiency is high, well up in the high 90s % + area, but it’s not 100%.

The “lost” energy goes in the resistance of the cables and overcoming the saturation voltage drops in the numerous semiconductor devices in the vehicles charger. The vast majority will be lost as heat, but a small amount as sound as the high currents involved make the wound devices vibrate ever so slightly. If charging in hot weather it’s possible that fans will come on to cool the batteries - that takes power as well.

As a rule of thumb I’d suggest that your calculation is about 95% correct - with the difference being for the reasons given.

That’s an interesting thought you’ve raised.
I had assumed that when on a DC charger, the power (kWh) shown on the chargers was what had been supplied to the car (in DC) not what the charger had/was consuming in AC.
Some Googling to be done here....