MG5 rapid charging speeds in freezing temperatures?

[Northfox]

Hello everyone! Been searching for an answer but didn't find so asking for help.

My issue is that I have an MG5 2022 SR (46 000 km driven), I've has it for a couple of weeks now. And I have not achieved more than 22-23 kW charge rates on rapid chargers (200kW 400V charge points, 7 different chargers). Should it be this way?

I've used traction battery warming for 1,5 hours before arriving to the charger. Also, I've tried not to heat. Driving a long distance and a short one before charging. Starting from 8%, 27% and 40% and NEVER getting higher charge rates than 24 kW peak, rapidly getting to 22 kW. Been driving with Comfort mode and Eco mode both, no real difference.

The weather here has been from -10 Celsius to -26 Celsius. At -26 celsius after a short driving (20 km or so) on Comfort mode I got 20-22 kW. After a long drive (140 km) on Comfort mode while -10 celsius I got first 22 kW and after a while on a second stop just 9.5-11 kW. And the strange thing is that while driving a long drive on Eco at -22 to -26 Celsius I got the same 20-22 kW. And also straight after driving from a warm garage to the nearest charger with battery warming on.

Also, from my previous EVs I've learnt that usually it goes that way that first charging might start slow, but then tends to speed up. With this one it might be lets say 21 kW at 10% and at 30% (after 30-45 min) just 19 kW and drop even to 12-13 kW while charging longer.

I've sat now 3-4 hours on charger on 300 km trip on two separate weekends watching snail speed charging, and feels wrong.

The car has been updated TWICE on MG on this period with no effect at all.

Any help? How does your MG charge on freezing weather?

 

[Northfox]

Also, today tried 200kW charger after 100 km trip, with 50 km pre-heating. The same 18 kW. But strange thing is that after I set battery heating on my consumption for during the rest trip fell from 22.2 kW / 100 km to 20.3 / 100 km. It is -5 Celsius today.

 

[MickeySw]

Also, today tried 200kW charger after 100 km trip, with 50 km pre-heating. The same 18 kW.

Pre-heating on an MG5 doesn’t work as one would think, i.e. that I heats the battery and keeps it at that level.

It only starts heating if the cell temperature is below ca 10deg C.

Once it reaches set temperature (around 30degC) the heater simply turns off.

Only when the cells have cooled below the initial 10deg can the process be restarted.

This cooling down is quick as the heating fluid is run trough a heat exchanger with ambient air.

Without battery temperature data via OBD dongle it’s near impossible to get the timing right.

 

[Northfox]

Pre-heating on an MG5 doesn’t work as one would think, i.e. that I heats the battery and keeps it at that level.

It only starts heating if the cell temperature is below ca 10deg C.

Once it reaches set temperature (around 30degC) the heater simply turns off.

Only when the cells have cooled below the initial 10deg can the process be restarted.

This cooling down is quick as the heating fluid is run trough a heat exchanger with ambient air.

Without battery temperature data via OBD dongle it’s near impossible to get the timing right.

Yes, I get that. But from MG Dealer this was The procedure they asked to follow, so I did. No effect.

Nevertheless, the battery temperatures should be around 10-30 deg with battery heating on while arriving to the charger and it should show charging speeds higher than 10-20 kW during more than a 1,5 hours charge (starting from less than 20% left, adding just 20 something kwhs on total)? The charging itself should warm the battery enough for proper charging rates?

 

[MickeySw]

Yes, I get that. But from MG Dealer this was The procedure they asked to follow, so I did. No effect.

No surprise

Nevertheless, the battery temperatures should be around 10-30 deg with battery heating on while arriving to the charger and it should show
charging speeds higher than 10-20 kW during more than a 1,5 hours charge (starting from less than 20% left, adding just 20 something kwhs on total)? The charging itself should warm the battery enough for proper charging rates?

Your battery will most likely be at 10deg when arriving at the Rapid Charger.

At this stage the heating should automatically activate but that doesn’t seem to be happening? The resulting low charge current alone won’t heat the cells significantly, especially if they are LFP..

 

[5teep]

My two pre fl MG5s would charge in the low 40s on a 50kw rapid when it was very cold, getting less than 25kw is out of the ordinary.
Unless the charger(s) you've been were all partially faulty (very unlikely if you tried that many), the chargers in my area have 4 x 12.5kw power supplies and will continue to work with one or more of them faulty.
My 21 SR didn't have battery heating at all, the later 22 LR did but I never knew if it was working or not so I ignored it.
Also, neither of them seemed to like ultra fast chargers, never getting more than about 44kwh from say a 150kw charger.

 

[Northfox]

Yes, it seems that the heater doesn't activate. And also somehow strange that the charge rate doesn't increase over time but decreases slightly.

And actually one of the chargers was 100kW shared charger (but no other vehicle connected) so that doesn't explain it either. Most of the chargers on my route are quite new Kempower chargers with high power fields (600kw to be shared or more), so charger faults or lack of Power are quite unlikely.

I'd be happy with 40ish kW charging wintertime, I can spend an hour charging but not hours like now...

 

[MickeySw]

Yes, it seems that the heater doesn't activate.

Can’t remember if one can monitor battery current on a pre-FL?

If possible, you can check if the heating activates: start the car, take a note of the battery current, manually turn on the battery heater, current should increase by 10-15A