Balance Charging....AGAIN!!!!

[reddeviluk]

Hi All, we’re very new to EVs and am looking for some advice, I’ve scoured the internet, even called MG themselves and, 24 hours later, and am no further forward.

Firstly the car in question is a Mk2 ZS EV Trophy Long Range. It’s only done approx 2000 miles and was purchased in June 2023.

All going great till it comes to a balance charge, to date, we have no charger at home and have not used the granny charger, so all charging has been at 22kW charger at Lidl etc, nothing too fast or slow.

We’re now concerned that the car needs a balance charge as mentioned by a few here, so I have basic questions that I cannot find the answer to online and even MG seem unable to answer.

For a balance charge, does the battery have to be at a certain % before starting?, or could I charge to 80% on a 22kW charger, then the remaining 20% as the balance charge?

Most chargers near me seem to be type 2, but 11.5kW chargers, plugging the car in shows it’s charging at a max of 7.4kW, is this ok, or does the balance charge NEED to be done on ONLY the granny charger or (as per MG) “any type 2 charger will do”, when asked if a 11.5kW type 2 charger was ok, they couldn’t answer……

The instructions say to do a balanced charge every month, but then MG said to only use the granny charger sparingly or in case of emergencies…..and to avoid charging to 100%.....which is it?.

I don’t really want to use the granny charger to balance the battery, certainly not once a month, so is any type 2 charger ok?. On speaking to others with other brands, they simply don’t bother, but the car is leased and so I don’t want it to get 2 years down the line and the leasing company say “you should have done this”, figure if we get into a good habit now, it’ll be less chew later.

I understand the concept is to charge to 100%, then leave it charging, once the blue lights under the flap are solid (and the car is at 100%), leave it charging till the blue lights go out, only then is it balanced.

Please Guys, there’s so much contradiction I’m flummoxed.

Rich

 

[Gadget Geek]

Hi there.

Hopefully this will clear up a few points for you.

The UK version of the ZS will only charge at 7kW on a type 2 charger. The charger may be able to supply 11kW and 22kW, but the cars inverter will only draw off 7kW.

The balance charge will occur when the battery reaches 100%, so it doesn't really matter where you start from. Once at 100%, the Battery Management System (BMS) will check each cell in the pack and bring them all to the same voltage. This can take a while if there is a significant difference between individual cells.

Balancing can only be performed with AC charging, that's either the granny charger at 2kWish, or at 7kW on a 7, 11, or 22kW charger.

 

[AndyL61]

It doesn't need to be 100% to balance. If for instance you set the charge limit to 80% once it reaches 80% and is left plugged in and charging then it will carry on at very low power draw and balance all the cells to the same voltage but at 80% soc. It is recommended to balance at 100% once every so often I should add.

 

[reddeviluk]

Ah that is perfect, that answers pretty much everything, if only MG could have told me that this morning. It's now my mission first thing.

So, just to confirm, I can do this at Lidl, which is a Pod Point charger, it's not a case of it reaches 80% or 100% and then stops charging, it will keep going until the cells are balanced. I'm guessing others have succeeded in a balanced charge at an AC charging point?...

Thanks again folks for the messages above, think this is really the last hurdle of EV ownership.

Rich

 

[Jomarkh]

Ah that is perfect, that answers pretty much everything, if only MG could have told me that this morning. It's now my mission first thing.

So, just to confirm, I can do this at Lidl, which is a Pod Point charger, it's not a case of it reaches 80% or 100% and then stops charging, it will keep going until the cells are balanced. I'm guessing others have succeeded in a balanced charge at an AC charging point?...

Thanks again folks for the messages above, think this is really the last hurdle of EV ownership.

Rich

Has the Lidl got any parking restrictions?
You could Rapid charge to 90% then fast charge to 100% and balance the battery, this could take anything from 20 minutes to a few hours depending on how out of bathe cells are.

 

[theboffin]

Is there a way to tell that your car is doing the balancing, and when it has finished? I've recently got my home charger, and did a 100% charge, and then left it, but couldn't tell if it had done it or not.

Is there a status somewhere?

 

[Jomarkh]

If you know you base usage of your house then check your IHD to see what the car is drawing, it should drop to a few hundred watts.

 

[reddeviluk]

Hi All, sorry for going silent, work caught up with me.

Just as a bit of feedback on this. We left the car on a Pod Point charger doing a super slow charger for most of the day. For some reason it didn't go past 3.4kW at any point. Left it on top it read 100%, the growth time was just getting pushed back minute to minute to we'd gone 20 minutes passed from the anticipated end time, the top green light was still flashing, so I walked away....

Typically approx 3 minutes after walking away I checked on the app and it said it had finished charging, the Pod Point app confirmed this so walked back to find all 4 sections of the light lit green and no longer flashing.

No suggestion that it had done a balanced charge, no difference at all except it was at 100% for the first time rather than 80%.

So I assume it's done or was never needed in the first place.

Rich

 

[AndyL61]

Hi All, sorry for going silent, work caught up with me.

Just as a bit of feedback on this. We left the car on a Pod Point charger doing a super slow charger for most of the day. For some reason it didn't go past 3.4kW at any point. Left it on top it read 100%, the growth time was just getting pushed back minute to minute to we'd gone 20 minutes passed from the anticipated end time, the top green light was still flashing, so I walked away....

Typically approx 3 minutes after walking away I checked on the app and it said it had finished charging, the Pod Point app confirmed this so walked back to find all 4 sections of the light lit green and no longer flashing.

No suggestion that it had done a balanced charge, no difference at all except it was at 100% for the first time rather than 80%.

So I assume it's done or was never needed in the first place.

RichView attachment 21095View attachment 21096

I don't think this will be balanced at all. I would assume as it is a public charger that it will stop charging at 100% . To balance it needs to be on a "dumb" charger that will carry on a supply after the soc is reached. This allows the car to pull a very low rate of charge "100 to 300 watts" while it balances. The best way to see this is on the app which will show the very low charge rate and also that it is still charging. This can take up to and even over an hour during which time your time to completion will always be the time it actually is because it doesn't know how long it will take.

 

[siteguru]

Public chargers may operate differently ... home charge points ("smart" ones) will stop charging when the car instructs the charge point to turn off the AC supply.

In my MG4 SE SR I can see when a balance is happening because the iSmart app shows approx. 20W (0.02kW) charge rate, and the predicted finish time keeps incrementing at the current time until such point that the car says Stop.

 

[theboffin]

Ah OK, thank you. I have a Zappi home charger, so I'll give this a go, and see what it does once it reaches 100% charge.

 

[pollenface]

Manual says to charge below 3 kW when balance is needed.

I believe using the "granny" at home will solve your issue.

 

[Lovemyev]

As your usage pattern is fairly low, do you need to charge to100% every single time you charge ???.
As you have a long range model, why not charge to 80% which should still offer you about 200 miles of predicted range.
The standard range with the LFP battery type has no ill effects from charging to 100% on every single occasion.
The long range has a slightly different protocol / recommendation for charging.
For daily shorter range trips, charge to 80% and then increase to 100% for the longer trips.
Do not become paranoid or stressed about trying to balance the battery every single time you take on a charge.
I also have a long range model that is 18 months old and covered a similar mileage.
I find charging to 80% suits almost 99% of our needs.
It has been charged to 90% about three times and about the same when charged to 100%.
ALL of our charging needs are performed by our home wall box, no public charging or rapid charging.

 

[MG steve]

I'm not sure where in the manual it says not to use a granny cable.

You need to top up to 100% at Lidl then find some way to use someones home charger or way to use your granny cable if you want to balance the batteries and wait a long time. To be honest if its a lease I wouldn't bother but it may come up with messages to force you to do it in the future.

 

[Lovemyev]

I'm not sure where in the manual it says not to use a granny cable.

You need to top up to 100% at Lidl then find some way to use someones home charger or way to use your granny cable if you want to balance the batteries and wait a long time. To be honest if it’s a lease I wouldn't bother but it may come up with messages to force you to do it in the future.

As of yet, I have not received a a warning message to advise on carrying out a balance cycle.
This maybe the case if you are using a rapid charger on a frequent basis.

 

[JCFlippen]

Is there a way to tell that your car is doing the balancing, and when it has finished? I've recently got my home charger, and did a 100% charge, and then left it, but couldn't tell if it had done it or not.

Is there a status somewhere?

The BMS will balance the battery when 100% charged and switch itself off when the process has been completed.

 

[AndyL61]

It will also balance at soc below 100% . 60, 70, 80 ,90. Will balance if set limit is reached and charger still left on.

 

[theboffin]

Thanks for the info. I wondered if it had to be at 100% to do it or not.

I've attached an image from my Myenergi/Zappi app, showing where it finished the charger, and then used a small amount for another couple of hours, when it was presumably balancing. This was at 7Kw. Hope that might be helpful to someone.

I'm on a Trophy LR btw.

 

[Lovemyev]

It will also balance at soc below 100% . 60, 70, 80 ,90. Will balance if set limit is reached and charger still left on.

The Gen1 ZS EV will only commence a balance cycle after the battery is fully charged.

 

[siteguru]

Is that because the Gen 1 has an LFP pack?