What's balancing? Do I need to do it?

[JJeep]

Does it need to be done? How?

 

[Rolfe]

Yes, if you want the battery to be functioning at its best. How, is simply that you charge the car to 100% on an AC charger and leave it connected to the power until it's finished doing its thing. Usually takes about 30-35 minutes. You can tell from the app, which will read "not charging" and show blank for charging power and finish time when it's done. If the finish time shows as the current time and the charging power shows as 0.0 kw, then it's still balancing.

If you're normally charging at home on AC the easiest thing to do is simply to leave it to go to 100% and give it that balancing time whenever you charge. Unless you need the car in a hurry, obviously.

 

[wattmatters]

Does it need to be done? How?

If the car really needs it, it will let you know. Else if you are already typically AC charging to 100% on a semi regular basis then it will look after itself, nothing to think about.

Normally balancing is something it'll need to do if it hasn't been fully charged for quite some time and/or charging for a while has been dominated by DC fast charging.

 

[siteguru]

And as @JJeep has the Standard (SE SR in UK speak) then his has the LFP pack, so will charge to 100% anyway unless he manually stops the charge. So even easier to do the balancing.

 

[Rolfe]

If the car really needs it, it will let you know. Else if you are already typically AC charging to 100% on a semi regular basis then it will look after itself, nothing to think about.

Normally balancing is something it'll need to do if it hasn't been fully charged for quite some time and/or charging for a while has been dominated by DC fast charging.

That advice is more relevant to NMC batteries, and @JJeep has the LFP battery. But yes, if the car is usually/often charged to 100% on AC and nobody cuts the power for the next half hour or so, it will be done without anyone even having to think about it.

 

[wattmatters]

That advice is more relevant to NMC batteries, and @JJeep has the LFP battery.

It would seem to apply equally to either.

It's entirely possible for people with LFP models to not hit 100% SOC for quite some time, e.g. if they use a granny charger they may not be able to achieve a full charge during off-peak tariff periods making the opportunity for a long slow full charge less frequent, or they don't have off-street parking and are reliant on public charging stations with practical limits on charging time, or are using mostly using DC fast charging on trips away from home when charging to 100% is not common.

Which is why I said:

Else if you are already typically AC charging to 100% on a semi regular basis then it will look after itself, nothing to think about.

 

[Rolfe]

Fair enough.

 

[tsedge]

The official recommendations are:

• SR: weekly charge to 100% and let it balance
• LR: monthly charge to 100% and let it balance
• Every 3-6 months, discharge to 10% and then charge all the way to 100% (for calibration)

 

[wattmatters]

The official recommendations are:

• SR: weekly charge to 100% and let it balance
• LR: monthly charge to 100% and let it balance
• Every 3-6 months, discharge to 10% and then charge all the way to 100% (for calibration)

Where are those official recommendations listed?

While we have been using the term "balance" that's not used in the MG manual wrt to the drive battery, they use the term "equalisation".

The user manual only recommends a monthly equalisation charge (p 294).

 

[tsedge]

Where are those official recommendations listed?

They have been issued by MG in the UK - I don't have the exact references to hand but it is a combination of what's on the website and what MG UK customer services have send to customers who have enquired.

We've had this advice confirmed over the years by various people in dealers.

There are lots of things that aren't in the manual.

 

[wattmatters]

They have been issued by MG in the UK - I don't have the exact references to hand

Anyone out there with a copy or reference? There is nothing about it on MG's website here.

There are lots of things that aren't in the manual.

I get that, but it is always preferable to provide links when referring to something as being official recommendations.

We've had this advice confirmed over the years by various people in dealers.

Frankly I'm not entirely sure I'd trust dealers. They have a habit of making stuff up.

Half the time the owners know more about the car than they do. Certainly the case here with owners constantly having to educate the dealers rather than the other way round.

 

[Mark Hewitt]

Frankly I'm not entirely sure I'd trust dealers. They have a habit of making stuff up.

Half the time the owners know more about the car than they do. Certainly the case here with owners constantly having to educate the dealers rather than the other way round.

Anything dealers say can be dismissed without further thought. If MG or SAIC themselves then fine.

 

[tsedge]

I don't have the time to look it all up - you'll find this stuff buried in past conversations over the last 2 years across these forums. But it has nonetheless emerged as the advice given and there are good rationales for each as have been discussed here many times over.

With MG the only thing we can do is piece together information and advice we get from different sources because there is no coordinated official communication. I withdraw the word 'official' if that makes you feel better and replace it with 'most consistent'.

 

[tsedge]

Anything dealers say can be dismissed without further thought. If MG or SAIC themselves then fine.

Some dealers are quite knowledgeable, others not. Some of our best information has come via dealers.

 

[wattmatters]

I withdraw the word 'official' if that makes you feel better and replace it with 'most consistent'.

It's not a matter of how I feel.

I was just hoping to find a copy or link to this information as I cannot find it. Having something provided by MG we can view / link to would be helpful.

Not everyone has been here for years while searching the forum isn't yielding anything.

A search for "balance charging" yields 10 pages of results and is not practically navigable.

A search for "official recommendation" yields one result:

Attempts to narrow down a search to find this elusive information have proved fruitless.

I did find these gems though, some of which have statements from somewhere in MG or a dealer and they are contradictory:

Charging 10%-100% every 3-6 months

I agree. The manual just describes type 1 &2 batteries and it took some digging to find out the 51 kWh battery is LFP. These tolerate deeper cycles better and like charging fully. It would be so easy to put a battery card into each car with details of management recommendations or just a QR code...

www.mgevs.com

Charging 10%-100% every 3-6 months

Well doing the 7-100% charge last night did help recalibrate the GOM and BMS. Drove to work today and have 97% left, where 2 weeks ago after charging from 50-ish to 100 it was at 88%. So it did actually help to calibrate the BMS. I think this should answer the questions above around what this...

www.mgevs.com

Charging 10%-100% every 3-6 months

Well doing the 7-100% charge last night did help recalibrate the GOM and BMS. Drove to work today and have 97% left, where 2 weeks ago after charging from 50-ish to 100 it was at 88%. So it did actually help to calibrate the BMS. I think this should answer the questions above around what this...

www.mgevs.com

Charging 10%-100% every 3-6 months

Well doing the 7-100% charge last night did help recalibrate the GOM and BMS. Drove to work today and have 97% left, where 2 weeks ago after charging from 50-ish to 100 it was at 88%. So it did actually help to calibrate the BMS. I think this should answer the questions above around what this...

www.mgevs.com

I agree with your assessment in the first link above. The information from MG on this is a mess when it need not be.

 

[tsedge]

I was just hoping to find a copy or link to this information as I cannot find it. Having something provided by MG we can view / link to would be helpful.

I understand, as I say I recall all of these being official advice from MG backed up with dealer recommendations. It is one of the most popular topics that has ever come up.

Not everyone has been here for years while searching the forum isn't yielding anything.

I appreciate that. At the same time, some of us have been over certain topics time and time again.

A search for "balance charging" yields 10 pages of results and is not practically navigable.
A search for "official recommendation" yields one result:

Attempts to narrow down a search to find this elusive information have proved fruitless.

Unfortunately the search function on the forum is poor and it is hard to get it to match the right responses.

 

[tsedge]

The other thing to say on this is that these are the same recommendations many manufacturers give who use the same batteries.