Issue with AC charging/New CCU fitted (Phase One SE LR)

[tsedge]

Might be a daft question. Those owners who have defective CCUs do you also have solar panels and or home batteries?

I have neither and prior to this happening I never AC charged anywhere except on my own Zappi. Which I did for almost all of my charging for these 9 months with only occasional DC charges for trips.

 

[tsedge]

I wonder - I have never fully discharged the battery, lowest ever being 20%. I have read more recently that full discharge is recommended every 6 months or so, something I never knew.

What about others? Have you ever gone down close to zero?

 

[DelBoy]

Might be a daft question. Those owners who have defective CCUs do you also have solar panels and or home batteries?

Not a daft question, I do have a Zappi, and during the summer I do mainly charge using solar, but the car/systems should be able to cope with this, an EV should be designed to do this as this is one of the reasons for having an EV

 

[DelBoy]

I have also been down to 10 miles left in the battery (2% or so) let's not make excuses for a batch issue, which, thankfully should/will be sorted under warranty. The operating range of systems should be tested, and the MG4 is not new as a system, it was in China for a while previously known as the Mulan.

 

[NLMGSAN]

It will not help all of you to get the the issue solved, MG isn't the only one.
Kia/Hyundai has a CCU problem too on all the latest models. Huge back log to service them. Expected delay 3 months or more....

 

[Talky Toaster]

Might be a daft question. Those owners who have defective CCUs do you also have solar panels and or home batteries?

No, I have neither batteries or solar.

 

[Talky Toaster]

It will not help all of you to get the the issue solved, MG isn't the only one.
Kia/Hyundai has a CCU problem too on all the latest models. Huge back log to service them. Expected delay 3 months or more....

Unfortunately I don't think the situation in the Red Sea is going to help any.

 

[Talky Toaster]

I wonder - I have never fully discharged the battery, lowest ever being 20%. I have read more recently that full discharge is recommended every 6 months or so, something I never knew.

What about others? Have you ever gone down close to zero?

I don't use the car a lot so I've been in the habit of charging between 60% and 80%. I'm going to change that to 40% to 80% which is what seems to be recommended by the 'health mode' on the battery display. A couple of times it charged up to 100% because for some reason my schedule got changed.

 

[FiferMG4]

Might be a daft question. Those owners who have defective CCUs do you also have solar panels and or home batteries?

I have both as I wanted to save on charging costs during the Summer (max charge rate of 3.6kW due to inverter limit) months, but I only noticed this problem when I started charging from the grid at the faster rate of 7.2kW in late October due to not having enough solar in the afternoon. Whether that was just a coincidence or not, I’ve no idea.

 

[FiferMG4]

I wonder - I have never fully discharged the battery, lowest ever being 20%. I have read more recently that full discharge is recommended every 6 months or so, something I never knew.

What about others? Have you ever gone down close to zero?

I think the lowest I got the car down to was somewhere around 12%. I hadn’t heard of that recommendation either. Is that to help with balancing the battery cells?

 

[tsedge]

I think the lowest I got the car down to was somewhere around 12%. I hadn’t heard of that recommendation either. Is that to help with balancing the battery cells?

I need to find the source - unless someone else can point me to it - it may have come from the workshop manuals.

 

[fnegroni]

I need to find the source - unless someone else can point me to it - it may have come from the workshop manuals.

It’s in the user manual.

 

[fnegroni]

I think the lowest I got the car down to was somewhere around 12%. I hadn’t heard of that recommendation either. Is that to help with balancing the battery cells?

It’s to help the battery management system to re-establish the full voltage range for each cell, which helps to ensure the percentage is accurate and that all cells are used.

 

[siteguru]

I suspect that this advice is more relevant to the NMC chemistry which has a more linear voltage curve. The LFP chemistry has quite a flat voltage curve, hence why 100% charges are recommended regularly.

 

[FiferMG4]

It’s to help the battery management system to re-establish the full voltage range for each cell, which helps to ensure the percentage is accurate and that all cells are used.

Thank you. That’s good to know. Once I can charge the car at home again, I’ll do this.

 

[tsedge]

Spoken to the garage at length: it is a new CCU that they have ordered. Timescales uncertain so may be a while before we have it available to be fitted.

 

[Steve T]

Mine is going in for inspection in a week or so, but one interesting thing I found is that if I use the Zappi on eco mode, which charges at 1.5kW, it doesn’t cut out. But as soon as I switch to 7kW it stops very quickly. In the chart from the snip attached, I’m charging for a number of hours at 1.5 kW until the scheduled fast charge comes on at 0030, then the charge stops soon after.

 

[tsedge]

Mine is going in for inspection in a week or so, but one interesting thing I found is that if I use the Zappi on eco mode, which charges at 1.5kw, it doesn’t cut out. But as soon as I switch to 7kw it stops very quickly. In the chart from the snip attached, I’m charging for a number of hours at 1.5 kw until the scheduled fast charge comes on at 0030, then the charge stops soon after.

Is this a one-off test or have you tried it like this for a while Steve?

I have tried a granny at 2.5kW and I get the same result (quickly stops) but not a very low charge rate - I could try that and see what happens.

Folks who have this issue, with your DC charging are you finding the charger knows the SoC of the car? I've noticed on the last few it doesn't (displays a question mark or stays at 0), could just be the chargers I've used or might indicate it is in some more basic CCS mode.

 

[FiferMG4]

Folks who have this issue, with your DC charging are you finding the charger knows the SoC of the car? I've noticed on the last few it doesn't (displays a question mark or stays at 0), could just be the chargers I've used or might indicate it is in some more basic CCS mode.

I charged the car this morning at an Osprey rapid DC charger and it was displaying the percentage as normal. Do you have any of those chargers nearby you that you could check with?

 

[tsedge]

I charged the car this morning at an Osprey rapid DC charger and it was displaying the percentage as normal. Do you have any of those chargers nearby you that you could check with?

Yes, there's all sorts, I'll just try another make next time I charge. Thanks.