Equalisation charging MG4

[redmg4]

How do l know when this is needed, and how do l do it? My MG 4 is the revised version with rear wash wiper and 64 kWh battery.

 

[Funks]

I'd like to know too, please.
I mostly charge at home, ie 7Kw, and I've only ever done 5 fast charges at public charges in the 7 months I've had the vehicle.

 

[dsimpkins]

Just do a charge to 100% about once a month. It will balance at the end of charging, will draw a small amount of power for about 30 minutes once it reaches 100%. If you don't do it, it will alert you on the dash that it needs it.

If you do lots of rapid charging, then you have to do this more often as the rapid charging means it can't perform equalisation/you aren't charging to 100% on a rapid charger as charging slows down past 80%.

 

[Funks]

Thanks, that’s great to know.
I've never had a reminder on the dash, so that’s good news.
As it happens I did a 100% charge just last week end on an "Octopus Green Energy Day".
I'll do the same next month, then.

 

[Martinonline]

As you have Trophy's with the NMC battery the car will balance/equalise using an AC EVSE at the battery level you set not just at 100%. Though it is recommended you do this occasionally dependent on your usage and every 6 months do a single less than 10% to 100% charge.

The important thing is to let the car decide when it has finished charging because you will see 0.0kW on the app when it is balancing because the app can't show you less than 100W.

Whilst balancing the app will show an end time synced to actual time. Wait until the app shows 'Start Charging' or the green charging port lights go out. If you interrupt the balancing eg by unlocking the car, then balancing may not resume.

 

[wattmatters]

How do l know when this is needed, and how do l do it?

If the car really needs a balance charge, it will tell you.

This is mostly only an issue for people who only ever DC fast charge. Anyone who normally uses AC charging won't have this issue.

When AC charging the car will do it for you automatically, just leave it on the AC charger.

Unlike the 51 kWh models, the 64 & 77 kWh models can do a balance at charge limit settings of less than 100% SOC, e.g. if you normally set it to charge to 80% (health mode), when it gets there it will continue to do a trickle balance charge for a while.

It typically only needs 5-10 minutes after the bulk charging ends. If however it's been mostly DC fast charged then the balancing at the end of an AC charge session may take a lot longer.

Every few months make sure you do a full charge to 100% from a low state of charge - as the BMS does occasionally need recalibration. It'll also do a balance but it's more about BMS calibration as the SOC indicator does drift and lose accuracy over time.

 

[fnegroni]

two things I’ve noticed on my SE:

- if charging to 100% at a rapid charger (DC), it will not equalise once reached 100%.

- if you enter the car after it’s equalising on AC power, it won’t run the heater. (No idea of any other options)

 

[Funks]

@#5 Whoa!! I'm looking up, and yes, that went straight over my head!

I'm a simple guy and I plug my car into the charger socket at home and set the amount of charge I think it needs on the Ohme app on my phone.
As I leave the car at night I read the state of charge, think how much charge I should give it, to give me something near 80% state of charge.
I'm on Octopus Intelligent Go, so the car charges at night and is ready for the time I've set on the Ohme app. Yes, it can do a one continuous charge or it staggers it throughout the nights charging period.

Question; should I be doing this, or should I always, somehow, (I don’t know how exactly, perhaps you all can tell me) set a fixed 80% and charge to that level.

Now I'm confused, what’s best for prolonging the battery's life?

 

[Martinonline]

With the Trophy battery type, you should only charge to >80% when you need it.

Your Ohme EVSE cannot know the charge level of the car (MG have not released the interface details) so you should set the level you require in the car or using the iSmart app. Set the Ohme to give you a charge greater than what you think you need. The car will stop the charging when it reaches its limit plus balance even if the Ohme has not supplied the amount you set.

As has been stated, the Battery Management System needs a low to 100% charge about every 6 months so that it can keep an accurate track of the battery state and thus the GOM a more accurate range prediction.

 

[Funks]

Ah! Got it!
So I set the 80% charge in the car as the "target" charge level, and set the Ohme charge level in its % terms, to give me something over 80%.
The car then stops charging at the 80% level set, BUT also does a small equalisation charge.

And, also every few months I need to do a 100% charge to keep the Battery Management System up to date with what it thinks is the actual battery capacity, and thus be able to give its best range prediction.

One last question, I'm no good at these acronyms, what is EVSE and GOM?
I'm old school and all this new flanged gadgetry on the car foxes me sometimes.

 

[Ian Key]

EVSE - Electric vehicle supply equipment

GOM - GuessOMeter. It's an indication of the amount of range left. But because this varies in the real world depending on your driving style, weather conditions and the amount of hills you have to climb, it can vary wildly.

 

[Funks]

Thanks everyone, I've now got a better understanding of what’s involved with charging my EV.

 

[Martinonline]

One warning though, the app/car sometimes resets the target battery level to 100% so a quick check before you start charging is a good idea. I have, in the past, reduced the required battery level after charging has started when I discovered the app/car had put it to 100%.