100% Balancing Charge - Frequency and Method

[andyphev]

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Every couple of months slow charge from 10-100% and leave it charging for an hour after it reaches 100%; there are few other tips in the instruction manual on battery care.

I use a 6amp charger for slower charging sometimes

 

[Bronwen]

I didn't get MG 3-pin charger when I bought my ZS so got one from Amazon for about £120, with phone app and WiFi and Bluetooth
Combined with MG app, all the info is there..??

What is the MG app? I have the charger, and a smart power point so I can turn the point on and off with my phone. But I’d love an app to know when the car is fully charged, rather than going out and turning it on.

 

[natasha y]

What is the MG app? I have the charger, and a smart power point so I can turn the point on and off with my phone. But I’d love an app to know when the car is fully charged, rather than going out and turning it on.

Hi Bronwen, not sure it will work with a hybrid. It’s pretty clunky and has connectivity issues if the car hasn’t been unlocked for a couple of days. It also went awol for a few days a little while back. Nobody in Oz could connect with their car! Once you get used to having it, it is problematic to lose it lol.

 

[fred12345]

What is the MG app? I have the charger, and a smart power point so I can turn the point on and off with my phone. But I’d love an app to know when the car is fully charged, rather than going out and turning it on.

it seems you can have it ... check out towards the bottom of the page:

MG3

www.mgmotor.eu

 

[pjohn]

Just because your "charger" is rated at 7.2kW doesn't mean that the car is loading it to 7.2kW. My ZS Mark 1 for example has a 6.6kW on-board charger.

It only charges to 6.0~6.1kW on Local Tesco charger. SO it depends on the charger AND the car on board charger Mk2 ZS is rated at 7.2kW

 

[tomsl]

11 kW "chargers" are fine for balancing. The issue is whether or not the "charger" will continue supplying power when the charge rate decreases to very low levels, as are typically seen during balancing. 11 kW "chargers" act the same as 7 kW and all other AC "chargers" in this respect.

Ah I see. My Wallbox goes as low as 4.1kW, so actually balancing should work?

 

[Coulomb]

My Wallbox goes as low as 4.1kW, so actually balancing should work?

Yes. Any AC "charger" (really just an Electric Vehicle Service Equipment or EVSE) uses the on-board charger, and so the car can control the charge down to very low levels when needed (e.g. less than 400W or 0.4 kW). The car will draw what it needs.

By contrast, at a rapid charger, the actual charging happens in some huge electronics stack outside the car, at a rate requested by the car. You probably can't ask for very small, precise charge currents from a rapid charger.
Even if you could, the rapid charger could stop the charge if the charge request falls below a certain value, so that others can make better use of the high powered charger. It may even stop the charge at say 80% or 90% SoC, all of which prevent balancing.

 

[tomsl]

Yes. Any AC "charger" (really just an Electric Vehicle Service Equipment or EVSE) uses the on-board charger, and so the car can control the charge down to very low levels when needed (e.g. less than 400W or 0.4 kW). The car will draw what it needs.

I guess this means my car does indeed balance. It actually reached 100% 20 minutes earlier and then drew ~4kW (min of the Wallbox) for some time.

 

[Coulomb]

It actually reached 100% 20 minutes earlier and then drew ~4kW (min of the Wallbox) for some time.

4 kW (6 amps times three phases at 230 V) is the lowest maximum that the Wallbox can tell the car to stay below. But the car can draw any current less than this limit if that's all it needs.

I often miss the early power throttling, because I charge from excess solar (manually at present), and rarely have more than 1500 W available near the end of the day when I can get the SoC to 100%. I've recorded drops to 1500 W, 3000 W, 1800 W, but mostly it drops straight to about 350 W (1.6 A at 240 V).

 

[Lovemyev]

If your car decides it requires a balance cycle, then as the car reaches 100% the charge will slowly decrease / ramp down in incremental stages.
It will reduce down to about 3.5 kW first, then after a short time, down to about 950 W then 500 W and just before completing as low as around 175 W.
Then the car will stop the charge and put your wall box back into standby mode.
If you have a home energy monitor, you can witness this gradual ramp down in power consumption here.
That’s assuming that the pack does require some level of balancing of course.
Otherwise it will be difficult to witness this happening.

 

[Coulomb]

It will reduce down to about 3.5 kW first, then after a short time, down to about 950 W then 500 W and just before completing as low as around 175 W.

I suspect that the exact power reductions will depend on the state of the battery cells. Perhaps also the MG model.

My ZS EV Mark 1 for example likes 345 W at the end, with occasional pauses at 1.5 kW, 1.8 kW, or 3.0 kW.

 

[Lovemyev]

I suspect that the exact power reductions will depend on the state of the battery cells. Perhaps also the MG model.

My ZS EV Mark 1 for example likes 345 W at the end, with occasional pauses at 1.5 kW, 1.8 kW, or 3.0 kW.

Same when we had the Gen1 ZS EV.
Lowest value I witnessed it pulling, was 175 watts.
Within five minutes, it would then return the wall box back to standby mode.

 

[peterseddon]

Just started using the eZS app and here is the battery data screen which shows a SoH of 98.32% and a cell imbalance of just 0.02 V across the cells

 

[DB Go Rex]

Am I the only one wondering why the forum settled on the word 'balancing' for this when the manual consistently calls it 'equalisation'?

No?

Just me then ?

 

[Caramaddy]

Am I the only one wondering why the forum settled on the word 'balancing' for this when the manual consistently calls it 'equalisation'?

No?

Just me then ?

I suppose that if something is equal then it is balanced? I take your point regarding the term used in the handbook.

 

[Lovemyev]

Am I the only one wondering why the forum settled on the word 'balancing' for this when the manual consistently calls it 'equalisation'?

No?

Just me then ?

Different wording - same thing in reality really.
Balancing the HV pack is generally a common terminology used by many other owners of EV’s that have been supplied by numerous other EV manufacturers.
MG have decided to book the trend and name the very similar process of balancing as “Equalisation” of the individual cells of the pack ???.
Just to have its own terminology that is different from the competition I guess ??.
A rose by any other another name I guess ?.

 

[pollenface]

As my home charger does not actually reach 7 kW (normally around the 6.5 kW) this would imply that it is acceptable for a balancing charge? What are your thoughts?

Manual says under 3kW.

 

[Coulomb]

Am I the only one wondering why the forum settled on the word 'balancing' for this when the manual consistently calls it 'equalisation'?

"Equalisation" is an unfortunate term; that's what they called the brutal process of over-charging flooded lead acid batteries. That was often the only way to balance them as there was no access to the internal cells in a 12 V module. You lost a bit of water, but that's OK, you were topping them up with water once a month anyway.

This is totally not suitable for any lithium based chemistry, and not even for sealed lead acid.