Rapid charging only 22kW on Mk2 MG ZS EV SR

[elkay62]

HI,

New owner of a Dec 2024 ZS which I believe was manufactured in 2023, I've had the car for about a month, and only charged on the granny charger up until now.

I have been preparing a few questions/comments to post in its own thread as a newbie, but a sudden requirement for a 250 mile round trip has arisen for Saturday (funeral). So today I tried out a couple of rapid chargers, as I know I will need to visit a charger early on my route home. Quite surprised to find that the first charger (Easygo 50kW CCS) only gave me c. 22kW, so decided to try a BP Pulse 150kW CCS. Again, I was only getting c. 22kW. Details...

• Both chargers visited after 10 mins driving, ambient temperature of 11°C
• Starting the charge at between 70-73% - I know there is a drop-off at >80%, but I expected more than 22kW in the 70's
• I only charged for about 15 mins at each, and I know the speed increases, but I was expecting it to start at more than 22kW.
• There were no other cars charging at all.

Should I be expecting more? If I am limited to 22kW, it looks like a couple of hours waiting for my charge on the way home .
Also raises concerns with me for annual trip to Manchester from Belfast via Scotland...

ELkay

 

[Tim Green]

On my mk1, it takes about a half hour to charge from say 10 miles to 165 miles which equates to about 40kWh, so that must be more that 22kW. How long does it take on the granny, which is only 3kW?

 

[elkay62]

I typically get around 2kW, so 8 hours overnight gets me about 16kWh, c. 55 miles, which is my typical weekly mileage. Which is why I'm happy with the granny charger for now. It's the 2 of 3 trips a year where I need to use public chargers is the problem.

 

[Tim Green]

Is yours a long range mk2? If so, it could be the charging profile is different from my mk1? Also trying to start a charge on DC at 70% could be the reason for a low charge rate as this starts to fall as it gets near 80%.

 

[elkay62]

No, it's a standard range (SR). I considered the 70% a factor, but reading loads of threads about rapid charging, I see no mention of it charging at such a low number before getting into the 80's, which is why I have asked in a new thread.

 

[Jomarkh]

Have you tried charging from under 50% on a Rapid?
Starting from 20-30% will get the peak rate

 

[Gadget Geek]

Fastned state their chargers deliver optimum output when the temperature of the battery is around 30 degrees C.

If it was 11 degrees and you had only driven 10 miles, then the battery may not have been at the optimal temperature.

 

[Roldorf]

Cold battery.

 

[fred12345]

No, it's a standard range (SR). I considered the 70% a factor, but reading loads of threads about rapid charging, I see no mention of it charging at such a low number before getting into the 80's, which is why I have asked in a new thread.

for fast chargers what they really recommend is to charge from when you are down to about 25% to charge up to 80% and drive off as after that takes much much longer to top up further... so your 70% definitely played a role to slow down the charge

 

[elkay62]

I didn't expect the factors mentioned (low temp, highish starting point) would make so much of a difference, But I'll find out tomorrow, and let let you know the result

 

[hermitdave]

Couple of things.
70% SoC will lower the over all state of charge

Battery temperature. Ensure you turn on battery heating prior to attempting rapid charge.
Our Tesla MY preconditions the battery at least 10 mins before it gets near super charger.

Colder battery lower is the rate of charge

 

[hmadsen]

Couple of things.
70% SoC will lower the over all state of charge

Battery temperature. Ensure you turn on battery heating prior to attempting rapid charge.
Our Tesla MY preconditions the battery at least 10 mins before it gets near super charger.

Colder battery lower is the rate of charge

Once in my Tesla i had to do a 100 mile trip to a SuC, the car started with the battery at negative 11 celcius and the destination was set for the supercharger.

Travel time was about 1½ hours.

The "Preheating battery for fast charging" message popped up as soon as i put it in drive in the driveway and the car was runing the heating for the entire 1½ hour drive to the SuC.

Takes a lot of time to heat 500 kg of batteries from -11 and up to about +40

 

[hermitdave]

Once in my Tesla i had to do a 100 mile trip to a SuC, the car started with the battery at negative 11 celcius and the destination was set for the supercharger.

Travel time was about 1½ hours.

The "Preheating battery for fast charging" message popped up as soon as i put it in drive in the driveway and the car was runing the heating for the entire 1½ hour drive to the SuC.

Takes a lot of time to heat 500 kg of batteries from -11 and up to about +40

Good point. I have only super charged a handful of times but you are right from my recollection I had been driving an hour and it still popped th preheating on.

 

[hmadsen]

Good point. I have only super charged a handful of times but you are right from my recollection I had been driving an hour and it still popped th preheating on.

I have tried a few times where my car was not charged up for a longer trip and suddenly work called and asked me to do this longer trip so had to do a charge session pretty quickly after leaving so not had time to heat the battery.

It really DOES impact the charge speed, once i elected to go to the Tesla charger that is 5 miles from where i live, but it was so painfully slow i elected to only charge until i would arrive at another SuC about 60 miles further away, but with a bit of headroom to allow for heating.

This saved me a lot of time because i arrived at the next SuC with a battery that was a lot warmer so it took 250KW for the first 20% until it started tapering down....First SuC was about 30KW and i bet a lot of it went into heating the battery.

I have even tried plugging in my own charger at home, just to have it say "Heating battery to accept charge" and it was plugged in to my charger at home for atleast 20 minutes before it started putting power into the battery, the first 20 minutes it was using all the electricity the "charger" was supplying to run the battery heater....Again sub zero temperatures outside.

 

[schmiedel]

I also own a SR with the LFP battery. In cold weather, don't expect anything over 40kW if you keep battery heater on, without it, 25kW is rather the limit.

However, I would consider cold weather everything under 5°C. We drove our ZS for a 4000km trip mostly under 5°C and it worked, but as I said, with battery heating on all time and knowing it would be rather slow. First 1-2 loading stops are a bit concerning, but then it becomes faster...

Over 10° it should be enough to precondition the battery for 10-15 minutes, and you should be able to get 40-45kW easily, but try to run it as low as possible (15% is a good target for starting a fast charge).

Only with temperatures over 20° you will get 50kW, and on warm days with 25-30° or more you will be able to get 60kW peaks.

However, starting with 70% is never a good idea to get fast charging, the 22kW you got seem pretty ok for a cold, rather full battery and the weather you described.

The charging curve is rather so that you will get the fastest possible speed up to like 50%, and then it starts descending slowly until at 90% where it will keep up like 10kW. But yes, loading from 10/15% to 75-80% is a good idea with this car, will take like 40 minutes in good conditions, up to 1 hour if it is really cold.