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Whilst having the update last week I got to speak to the technician. We’ve all wondered what the annual service includes, top up the washer bottle, look round the car, see if it still has brakes, but I was told they do a full balancing charge, presumably to check the health of the battery!
 

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When taking it in for service you need to make sure that your car has a high state of charge then otherwise it could be there for hours.
 

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but I was told they do a full balancing charge, presumably to check the health of the battery!
Did he go on to say WHY they bother doing this ?.
My dealer is about about 60 miles away, so I could be there a long time !.
Do they just charge the battery back up to full, as part of the service schedule, or does charging it offer another function to the checking process ?.
If there is good reason for fully charging the car ( other than returning with a full battery ) the charging process is likely to take longer than the service !.
 

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To do balancing doesn't it need to be at a low state of charge and full charged on the granny for something like 16 hours according to the manual?
 

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To do balancing doesn't it need to be at a low state of charge and full charged on the granny for something like 16 hours according to the manual?
That is why I am thinking along the lines of a “courtesy“ charge instead ?.
Helps justify the cost / time spent at the dealership,
another exercise in “Smoke and Mirror’s” I guess ?.
 

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Do they just charge the battery back up to full, as part of the service schedule, or does charging it offer another function to the checking process ?.
I only got Zoe back from a service once with a full charge. They had plenty of time to charge it as I always had them pick it up and return after (the excess on the courtesy car was £2k!). I suppose they had room on the charger the time they charged it.
 

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To do balancing doesn't it need to be at a low state of charge and full charged on the granny for something like 16 hours according to the manual?
No. That's not necessary. A balance is done every time you charge to 100% regardless of the charging method. It's the longest part of the charging cycle, taking somewhere around half an hour (plus?). That's why you should only charge to around 80% on a rapid.
 

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Helps justify the cost / time spent at the dealership,
another exercise in “Smoke and Mirror’s” I guess ?.
Yeah, I smell BS. You'd think they'd have stopped doing by now. I suppose the MG lot are still in the learning stage. :whistle:
 

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Whilst having the update last week I got to speak to the technician. We’ve all wondered what the annual service includes, top up the washer bottle, look round the car, see if it still has brakes, but I was told they do a full balancing charge, presumably to check the health of the battery!
From my experience of dealer staff over the years, you have to take whatever they say with a pinch of salt, "full balancing charge" is most likely just bu***hit lies. Especially as the car automatically does this periodically anyway, and any car presented to them in a low state of charge will be kicking around in the way for hours if it was true.

They needn't start giving me any BS, I know the first service is virtually nothing, a visual, diagnostic plug in, and update any free MG recommended software fix's. I accept this, I'm only taking it in to pay the ransom to keep the warranty intact, so expect to wait while it's done and be out within an hour at most. They'll be told to skip the complimentary wash & scratch, so that should save some time for them.
 

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They needn't start giving me any BS, I know the first service is virtually nothing,
My car wasn't ready when I went for my appointment to pick it up. I managed to get the first year's servicing thrown in as a result using exactly that argument - "it's nothing for you but worth it for me"..
 

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Discussion Starter #11
I don’t think i was trying to make out there is anything to do at a first service, just that I was complaining about how I couldn’t stop my Rolec charging to 100% all the time unless I got up during the night. The guy just said they were instructed to do a balancing charge as the service. I can see that if you are measuring the health of the battery you just might have to?
 

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just that I was complaining about how I couldn’t stop my Rolec charging to 100% all the time unless I got up during the night.
But, Brian, you don't need to. It's perfectly fine for you to charge to 100% every time. It won't actually be full. The Battery Management System (BMS) will not allow you to fill to 100%. It keeps a buffer at top and bottom.

The battery is somewhere in the region of 46 to 47 kWh. 42 (and a bit) kWh are available to use. AFAIK it keeps 2 (and a bit) kWh in reserve at the bottom (stops you emptying the battery) and another 2 (and a bit) that can't be charged at the top.

It's not like laptop and phone batteries, where there is no BMS. Your battery is well protect by the BMS and the active cooling from the AC.

That being said, some say that it's not a good idea to leave it full if you're not going to use it for a while. I'm not sure about the validity of this, given that as per the BMS the battery is never full, but, hey, sometimes you have to swing with caution.

Have a look at some of Bjorn Nyland's videos on this subject.

PS: If you don't charge to 100% you'll never balance you cells and that 'can' be harmful.
 

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But, Brian, you don't need to. It's perfectly fine for you to charge to 100% every time. It won't actually be full. The Battery Management System (BMS) will not allow you to fill to 100%. It keeps a buffer at top and bottom.

The battery is somewhere in the region of 46 to 47 kWh. 42 (and a bit) kWh are available to use. AFAIK it keeps 2 (and a bit) kWh in reserve at the bottom (stops you emptying the battery) and another 2 (and a bit) that can't be charged at the top.

It's not like laptop and phone batteries, where there is no BMS. Your battery is well protect by the BMS and the active cooling from the AC.

That being said, some say that it's not a good idea to leave it full if you're not going to use it for a while. I'm not sure about the validity of this, given that as per the BMS the battery is never full, but, hey, sometimes you have to swing with caution.

Have a look at some of Bjorn Nyland's videos on this subject.

PS: If you don't charge to 100% you'll never balance you cells and that 'can' be harmful.
Just to correct you, phones and laptops most certainly do have a BMS! They would be blowing up all the time if they didn't...
 

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Just to correct you, phones and laptops most certainly do have a BMS! They would be blowing up all the time if they didn't...
Do they do the same as an EV BMS? Spare capacity at top and bottom?
 

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Do they do the same as an EV BMS? Spare capacity at top and bottom?
They'll stop charging at a given upper voltage and cut power at a given lower voltage, so yes, almost certainly won't be as sophisticated as an EV bms.

You can't run any lithium battery without a bms as if you overcharge, they catch fire, and if you run them to zero, they catch fire the next time you try to charge them! They pretty much demand respect! ;)
 

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They'll stop charging at a given upper voltage and cut power at a given lower voltage, so yes, almost certainly won't be as sophisticated as an EV bms.

You can't run any lithium battery without a bms as if you overcharge, they catch fire, and if you run them to zero, they catch fire the next time you try to charge them! They pretty much demand respect! ;)
Thanks. I didn't know that. I'm rather ignorant about phones and such. I just use them and never think about it.
 

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My new Samsung tablet allows me to limit the charge to maxium of 80% in the setting but still shows 100% on the display which is clever and you can turn of fast charge too so it only slowly charge but I think for what extra wear it does I replace the phone before then same with the car.

This is my 3rd ev in 7 years. I notice a big change. Can only imagine what it be like in a other 7 years.
 
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