Charge rate query

[Emu7]

I charged my MG5 long range at an osprey ccs "max 50k" charger today. I haven't charged away from home before, where I use an ohme 7kw charger overnight.
I was surprised that this osprey charge wasn't quicker. I had 68% battery on arrival. Does this look about right to those of you who are experienced?
Thanks in advance.

 

[Jomarkh]

Hi, at 68% i would not have bothered to use a rapid as the charge rate drops off at 80% and if you get to 95% there have been issue with MG5's not working as the HV battery shuts down.
You were lucky.
It all looks ok for how high you went.
Just stick to 20 to 80%.

 

[Emu7]

Hi, at 68% i would not have bothered to use a rapid as the charge rate drops off at 80% and if you get to 95% there have been issue with MG5's not working as the HV battery shuts down.
You were lucky.
It all looks ok for how high you went.
Just stick to 20 to 80%.

Thanks very much for your reply.

I hadn't heard this about the HV battery shutting down. Is there a thread about it? I've tried a search but ended up down a rabbit hole.
I charge to 90+ at home, and 100 +balancing once a month. No problems so far but it's early days for me. Are you saying its unwise to regularly go over 80% charge?

 

[emmrecs]

@Emu7

My understanding is that the strong recommendation to not regularly charge to above 80% applies to the use of rapid (DC) chargers not to “standard” home chargers.

Hopefully I’ve got that right!!

 

[Ozzie1989]

Hi Emu7, there are lots of factors that could 'slow' your charge down using a rapid charger.

Firstly as has already been said, up to 80% the charge you would have received would have been well, rapid. After 80% the charging curve drops off dramatically (by design to protect the battery).

Generally when it comes to rapid chargers, and for vehicles with our battery type, it is widely accepted that a charge to 80% is the norm. If you were completing a longer journey requiring multiple charges, you'd find it quicker to do multiple rapid stops between 20-80% SOC than to sit there waiting for that last 20% to complete.

Another factor is battery temperature, the colder it is the lower the charging rate. You could use the battery pre heat option on a cold day, but this will reduce your range slightly so only use it for 30min prior to charging if you are sure you have enough to reach the charger. Equally if the battery is too hot it can have the same effect, but the battery is liquid cooled so isn't too much of an issue.

I would say, get yourself down to 20-30% SOC then repeat your experiment stopping at 80%, I think you'll find it's a lot quicker

 

[Emu7]

Thanks, this has been very helpful! Long journey ahead today, so I'll try out your suggestions

 

[Gomev]

Thanks, this has been very helpful! Long journey ahead today, so I'll try out your suggestions

Despite everything else that has been said, you were very wise to have done a test charge at a rapid before you set off on your long journey.
You can rest assured now that the rapid charging works and how you do it.

 

[biffo]

Thanks very much for your reply.

I hadn't heard this about the HV battery shutting down. Is there a thread about it? I've tried a search but ended up down a rabbit hole.
I charge to 90+ at home, and 100 +balancing once a month. No problems so far but it's early days for me. Are you saying its unwise to regularly go over 80% charge?

This 80% on a DC charger is a general rule based on the above mentioned slow down in charge rate around this point (in actual fact, it's nearer 83% where the slow down happens) - it varies between manufacturers and models - hanging around when only getting half the initial rate is deemed pointless by some, but it can be useful if it adding an extra 5 or 10% means no second stop - particularly where charger availability is limited due to being either busy or broken.

Some people will utterly dispute that going above 80% is ever a valid option - however, there is absolutely nothing technically to stop you doing this if it meets your needs - aside from the 95% which seems to be an issue. The etiquette of doing this is a whole other can of worms!!!

This graph shows the charge rate of the facelift ZS EV - the MG5LR won't be exactly the same, but since the battery and BMS are closely related, it's not going to be completely different. I've seen 80+ kWh on an MFG 150kWh (only that speed for an 800V car, going to be a max of 100kWh for a 400V car) but also saw 22kWh on a 50kWh unit the other week with cold weather and battery.

https://support.fastned.nl/hc/en-gb/articles/360037129533-Charging-with-a-MG-ZS-EV-?_ga=2.269220657.1577478496.1643500096-1927422190.1643500096