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Battery equalisation on ZSEV Trophy LR

Nickel

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Swansea, Wa;es
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MG ZS EV
We have a ZS EV Trophy LR. We normally charge it (on a 7kW home charger) to 80%, taking it up to 100% when we have a long journey coming. We've had the car since October and have never seen it equalise the battery pack.

Our previous ZSEV did this every time you charged to 100% if you left it to do so. This car charges to 100% then switches off (per the iSmart app).

I spoke to my dealer yesterday and was told that to initiate an equalisation charge, the battery needs to be drained as low as possible without risk of being stranded and then charged on a granny charger. This will take upwards of 30 hours...

The manual implies that an equalisation charge can be done on a 7kW AC charger (as before) and the car only needs to be taken down to the low battery light coming on, and it should not be taken down to said light flashing. That will probably take about 11 hours or so to recharge & equalise.

These are quite different requirements. Can anyone cast the light of practical experience on this?
 
Just leave the charge going after 100% do not unplug. The car will then self equalise until it is happy. Dealer is talking rubbish.
 
If you mainly use your 7kW EVSE then the battery balance shouldn't take to long.
A lot of rapid charging can put the cells out of balance.
As above just leave it plugged in overnight and it will sort itself out and reduce the power and shut off when done.
 
Just leave the charge going after 100% do not unplug. The car will then self equalise until it is happy. Dealer is talking rubbish.
Unfortunately, that doesn't seem to be what is happening. It absolutely was with the 2020 Mk I ZSEV, You could tell it was equalising by the change in state of the "breather" light.

We've only had the MkII since October, so there's been a limited number of 100% charge requirements. But watching the charge close in on 100% via the MG iSmart app, charging just stops when it reaches 100%, without any sign of a pause to equalise or a reduction in supplied power as it equalises. I think it was running at 6.4kW right up to 100% the last time I looked.

And I don't think the new charging status lights have an "equalising" display mode.
 
We have a ZS EV Trophy LR. We normally charge it (on a 7kW home charger) to 80%, taking it up to 100% when we have a long journey coming. We've had the car since October and have never seen it equalise the battery pack.

Our previous ZSEV did this every time you charged to 100% if you left it to do so. This car charges to 100% then switches off (per the iSmart app).

I spoke to my dealer yesterday and was told that to initiate an equalisation charge, the battery needs to be drained as low as possible without risk of being stranded and then charged on a granny charger. This will take upwards of 30 hours...

The manual implies that an equalisation charge can be done on a 7kW AC charger (as before) and the car only needs to be taken down to the low battery light coming on, and it should not be taken down to said light flashing. That will probably take about 11 hours or so to recharge & equalise.

These are quite different requirements. Can anyone cast the light of practical experience on this?

I asked this same question a couple of month ago and was informed that it’s only rapid DC chargers that unbalance the battery cells. Therefore, if you only use your 7kWh (AC) charger (as I do) that the battery cells have not been unbalanced, and therefore no balancing is required.

I’m sure someone will correct me if I’m wrong, but this seems to be a sensible explanation…
 
I asked this same question a couple of month ago and was informed that it’s only rapid DC chargers that unbalance the battery cells. Therefore, if you only use your 7kWh (AC) charger (as I do) that the battery cells have not been unbalanced, and therefore no balancing is required.

I’m sure someone will correct me if I’m wrong, but this seems to be a sensible explanation…
It's probably fair to say more rapid DC charging is going to result in cell imbalance.

I don't think it's impossible for it to happen with home charging... depending on charging patterns
 
Try unplugging it then plug it back in and start the charge again. If it's equalising it will draw about 3kW initially then drop back down to 300W or so.
If you have a smart meter then it should show as still drawing power on your display when it's balancing.
 
I asked this same question a couple of month ago and was informed that it’s only rapid DC chargers that unbalance the battery cells. Therefore, if you only use your 7kWh (AC) charger (as I do) that the battery cells have not been unbalanced, and therefore no balancing is required.

I’m sure someone will correct me if I’m wrong, but this seems to be a sensible explanation…

It's probably fair to say more rapid DC charging is going to result in cell imbalance.

I don't think it's impossible for it to happen with home charging... depending on charging patterns
Regen will also unbalance the cells
 
As the regen is much weaker on the Gen 2 than the previous Gen 1 model, then I guess this could be seen as a small advantage then of reducing a small imbalance in the cells in the pack then :ROFLMAO:.
To be honest @Nickel we had a Gen 1 before our new(ish) Gen 2 model now and comparing the balancing process across both models are a little different I think.
Even the balancing cycle process on the Gen 1 was different, depending if you where pre or post BMS update.
Pre update, about 30 - 45 mins to complete, post BMS ........ well, someway between 3 - 4 hours.
Never less than 2.5 hours on a GOOD day !.
Could it be suggested that your balance cycle is short, because your pack does not require it ?.
As you are like myself and therefore NOT a regular rapid charger, then this does help of course.
I do find the advice given for balancing on the LR model a bit contradictory any way, but hey ho.
 
Thanks everyone for the input, but I must admit to a lack of certainty as to whether people are telling me what they think will happen, or have actually balanced/equalised a Mk II LR.

Incidentally, my MK I never took anything like 3-4 hours to balance, before or after the BMS upgrade. I didn't log it as such, but I'd take a guess at 1.5-2 hours. Somewhere in that region.

My car's at about 75% SOC at the moment. I will try and let it go down to the low warning coming on and see what happens then. That's a first step. Hopefully I won't have to charge it for a long trip before then.

Incidentally, does anyone know when the warning does come on on a LR model? I think it was 25% SOC on the Mk I, but I imagine it's a lot lower on the LR because of the increased capacity/range. The manual doesn't say, as far as I can find.
 
I charge my car between 40 to 80% as advised. I have the same when I do a 100% balance it stops and according to the Ismart app it is not drawing current and the podpoint does not state it is charging?
 
Thanks everyone for the input, but I must admit to a lack of certainty as to whether people are telling me what they think will happen, or have actually balanced/equalised a Mk II LR.

Incidentally, my MK I never took anything like 3-4 hours to balance, before or after the BMS upgrade. I didn't log it as such, but I'd take a guess at 1.5-2 hours. Somewhere in that region.

My car's at about 75% SOC at the moment. I will try and let it go down to the low warning coming on and see what happens then. That's a first step. Hopefully I won't have to charge it for a long trip before then.

Incidentally, does anyone know when the warning does come on on a LR model? I think it was 25% SOC on the Mk I, but I imagine it's a lot lower on the LR because of the increased capacity/range. The manual doesn't say, as far as I can find.
On a long trip before Christmas, mine came on as it changed from 25% to 24%
 
On a long trip before Christmas, mine came on as it changed from 25% to 24%
That's when the Mk I warning came on, as best could be judged. Did it do an equalisation charge afterward? I suppose the Christmas festivities may have taken precedence over monitoring EV behaviour, even if you charged on an AC charger!

P.S. My wife has reminded me that when the car reaches 100%, our home charger goes immediately back into the blue standby mode, a strong indication that there's nothing else happening... I.e. like @Nicko 's
 
Incidentally, my MK I never took anything like 3-4 hours to balance, before or after the BMS upgrade. I didn't log it as such, but I'd take a guess at 1.5-2 hours. Somewhere in that region.
As you say then, just a guess ! 🤷‍♂️.
Numerous Gen 1 owners ( including myself ) have tracked via their home energy meters etc and have definitely witnessed two different balance cycle times, for both pre and post mod BMS updates.
Part of the BMS update was to increase the size of the buffer at the top of the HV pack.
This could be clearly felt even after charging to 100% as regen was available almost instantly, not so pre BMS update as the regen energy had no where to go.
This extra space created, appeared to have the side affect of increasing the balance cycle time.
Which kind of makes sense really.
Many members consistently reporting 30 - 45 mins pre BMS and much longer times post BMS.
I don't remember anybody achieving anything less 2.45 even after carrying out numerous balance cycles almost night after night.
The best I achieved was 3 hours, but usually around 3.30 to 4.00 hours.
If I told you that the first balance cycle I made directly after the BMS update was 8 hours and my car was NOT affected by the software bug !.
Some owners where even resulting in charging to 100% then, either take the car on a very small drive of about 1 mile, or just leaving the car powered up and running the heater flat out until the charge level dropped a little.
Then anything below 98% SOC and then putting the car straight BACK of charge again to commence another balance cycle !.
It all got a little crazy, but some packs had been badly affected by the software bug and the range in their cars had massively reduced.
Charing via CCS D/C Rapid charging, just made the whole thing even worse, because the battery cell's where becoming more and more out of balance by doing this !.
I have not actually timed the length of the balance cycle on our LR Gen 2 model TBH.
Worth noting that most manufacture will under report what the upper battery space really is, and therefore will keep some space hidden.
This gives them the ability to allow for the initial battery degradation, that can be seen very early in the batteries life.
This avoids bind panic when owners of new EV's start reporting big drops in there range quickly !.
So, does short balance times on the LR Gen 2 model suggest that any imbalance, is minor ???.
IF the balance cycle was only 20 - 30 minutes, then that would be really easy to go unnoticed by the owner ?.
I have not been low enough on our LR pack to get the "Low Battery" warning, that was orange coloured warning on the Gen 1 model ?.
As no percentage gauge was evident, I seem to remember it triggered when we had about 40 miles of range left on the GOM and well close to home.
But as time / mileage and charging sessions increased with age, the orange warning message began to trigger earlier on that same trip in very similar weather conditions etc.
On our last trip, it triggered when we where only half way home !.
We made it okay, but it was tight.
Proving I guess that the battery had lost some of it's capacity over the time we had the car.
Lesson clearly learnt here, build in some future battery degradation into your choice of EV.
 
I’ve had my Mk II LR since Sept, only ever charged it on 7Kw charger. I’ve charged to 100% about 5 times, been sub 25% a few times, resulting in low power warning, and it’s never balanced. Or if it has, it has only done it for <10mins, as the charge point has flicked to blue around the time iSMART said charge was due to finish.
 
Charge finish is the end of the balancing process it can sit at a100% before charge finish comes up
 
Charge finish is the end of the balancing process it can sit at a100% before charge finish comes up
So the estimated finish time on iSMART takes balancing in to account also? Just wondering, as last week it said due to finish charging at 14:28 and it clicked off at 14:32 (Before you ask, I know the exact times as I keep a note of the charging times, speeds etc, so I can calculate how much charge I can get, in a certain amount of time, as the charger at work is shared between other drivers).
 
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