MG4 Equalisation Charge

Rolfe said:
Can someone clarify for me just what is meant by "frequently" using rapid chargers, and how this affects the SR battery?

There is a rapid charger at the end of my street which is no more expensive than my domestic electricity supply. One charging regimen that seems convenient to me is to give the car as long as it's allowed on that charger (55 minutes, which gets about 50% battery capacity filled), then to plug it in to the granny charger at home just to bring it up to 100%, however much further that was. (The one time I tried it so far, I took it from 92% to full on the granny charger.)

Does this final stage on the granny charger balance the cells and so negate any imbalance from using the rapid charger?
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Don’t fully charge with a rapid - only use a 7 kw home wall charger or the granny type from 80 to 90 % upwards. That’s been my mantra so far.
 
Archev said:
Don’t fully charge with a rapid - only use a 7 kw home wall charger or the granny type from 80 to 90 % upwards. That’s been my mantra so far.
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That was what I was thinking. You reckon that will be OK? The CCS charger at the end of the road only allows 55 minutes max so charging up to full on that isn't going to happen anyway unless the battery is more than half full before I start. Last time I think I charged from 92% or 93% to full with the granny charger, and I thought it was all quite convenient.

If I got back in the evening and needed the car again the next morning I could do say 45 minutes on the rapid charger then on the granny charger overnight, and it would be at 100% by morning. That would be good for the battery, you reckon?
 
Rolfe said:
That was what I was thinking. You reckon that will be OK? The CCS charger at the end of the road only allows 55 minutes max so charging up to full on that isn't going to happen anyway unless the battery is more than half full before I start. Last time I think I charged from 92% or 93% to full with the granny charger, and I thought it was all quite convenient.

If I got back in the evening and needed the car again the next morning I could do say 45 minutes on the rapid charger then on the granny charger overnight, and it would be at 100% by morning. That would be good for the battery, you reckon?
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Aye that’s my method 👌. In fact it was very nice during the “free charging” time since I got my first ev ( the ZS ) and up to the charging times I used to do just that. Now I just add an hour or so during my 10 hours of off peak power each day whenever the car (now long range 5) is getting close to 40 or 50 %.
 
Rolfe said:
That was what I was thinking. You reckon that will be OK? The CCS charger at the end of the road only allows 55 minutes max so charging up to full on that isn't going to happen anyway unless the battery is more than half full before I start. Last time I think I charged from 92% or 93% to full with the granny charger, and I thought it was all quite convenient.

If I got back in the evening and needed the car again the next morning I could do say 45 minutes on the rapid charger then on the granny charger overnight, and it would be at 100% by morning. That would be good for the battery, you reckon?
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I think you are worrying too much about the battery - and you have the longer lived LFP version anyway.

In practice it is hard to go wrong, so long as you:
  • Charge the LFP SR weekly to 100% on an AC charger, to balance it. You can charge to 100% more often than this including on Rapid CCS chargers, that won't harm it.
  • Charge the NMC LR monthly to 100% on an AC charger, to balance it. 100% range charges more often than this are fine (including on Rapid CCS chargers) so long as you don't leave the car at 100% for a long period of time.
  • Normally charge the NMC LR to 80% for everyday use.

Really, both these battery technologies will last longer than the rest of the car and longer than an ICE engine would, so no need to worry.

The only way people really go wrong is not to follow the above advice - eg never doing balancing charges and/or only using fast chargers.
 
A 50kW DC charger should be able to almost "fill" the SE SR in 55 minutes - certainly should be able to get from 10% to 80% in that time.
 
Archev said:
Aye that’s my method 👌. In fact it was very nice during the “free charging” time since I got my first ev ( the ZS ) and up to the charging times I used to do just that. Now I just add an hour or so during my 10 hours of off peak power each day whenever the car (now long range 5) is getting close to 40 or 50 %.
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That charge-point at the end of my road was free until, I think, January last year. It's still a hair cheaper than my domestic electricity price so I can't complain. I think if it was still free there would be a queue round the block to use it, now!

tsedge said:
I think you are worrying too much about the battery - and you have the longer lived LFP version anyway.

In practice it is hard to go wrong, so long as you:
  • Charge the LFP SR weekly to 100% on an AC charger, to balance it. You can charge to 100% more often than this including on Rapid CCS chargers, that won't harm it.
  • Charge the NMC LR monthly to 100% on an AC charger, to balance it. 100% range charges more often than this are fine (including on Rapid CCS chargers) so long as you don't leave the car at 100% for a long period of time.
  • Normally charge the NMC LR to 80% for everyday use.
Really, both these battery technologies will last longer than the rest of the car and longer than an ICE engine would, so no need to worry.

The only way people really go wrong is not to follow the above advice - eg never doing balancing charges and/or only using fast chargers.
Click to expand...

I'm just trying to get it clear what I should be doing, so as to go on in the right way.

What I was really asking was, does it count as a balancing charge if you go most of the way with a rapid charger, then do the final 10% or so with a granny charger? I think the answer is yes.
 
Rolfe said:
That charge-point at the end of my road was free until, I think, January last year. It's still a hair cheaper than my domestic electricity price so I can't complain. I think if it was still free there would be a queue round the block to use it, now!
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That’s exactly what happened - human nature ran amock 🤩
 
siteguru said:
A 50kW DC charger should be able to almost "fill" the SE SR in 55 minutes - certainly should be able to get from 10% to 80% in that time.
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I got from about 47% to about 92% or 93% in 52 minutes. Power drawn 26.8KWh according to the ChargePoint Scotland app. It was quite chilly though and the car hadn't been driven (other than 400 yards to the charger) and the battery hadn't been heated. I was only trying it out, rather than needing maximum charge.

According to ChargePlace Scotland, the charger is rated at 52KW.
 
Rolfe said:
I'm just trying to get it clear what I should be doing, so as to go on in the right way.
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Understood and similarly I am just trying to make it clear for everyone.
Rolfe said:
What I was really asking was, does it count as a balancing charge if you go most of the way with a rapid charger, then do the final 10% or so with a granny charger? I think the answer is yes.
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Yes it counts.
 
Rolfe said:
I got from about 47% to about 92% or 93% in 52 minutes. Power drawn 26.8KWh according to the ChargePoint Scotland app. It was quite chilly though and the car hadn't been driven (other than 400 yards to the charger) and the battery hadn't been heated. I was only trying it out, rather than needing maximum charge.

According to ChargePlace Scotland, the charger is rated at 52KW.
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Tut tut tut - heated batteries - apps - I-smart ?? All these new fangled doo-hickies on cars these days ?? You should have tried it in the olden days - before fours 🤣🤣🤣
 
tsedge said:
I think you are worrying too much about the battery - and you have the longer lived LFP version anyway.

In practice it is hard to go wrong, so long as you:
  • Charge the LFP SR weekly to 100% on an AC charger, to balance it. You can charge to 100% more often than this including on Rapid CCS chargers, that won't harm it.
  • Charge the NMC LR monthly to 100% on an AC charger, to balance it. 100% range charges more often than this are fine (including on Rapid CCS chargers) so long as you don't leave the car at 100% for a long period of time.
  • Normally charge the NMC LR to 80% for everyday use.

Really, both these battery technologies will last longer than the rest of the car and longer than an ICE engine would, so no need to worry.

The only way people really go wrong is not to follow the above advice - eg never doing balancing charges and/or only using fast chargers.
Click to expand...
Great post.
 
Hope it’s not cheating to ask about the ‘other end’ of the battery. I have read that it should be run down occasionally to below 10% before charging up. Is this recommended / necessary / unnecessary?
 
It's in the manual and there is a thread on this specifically. Mainly, nobody is entirely sure whether the long charge has to be done in one continuous charge or whether you can split it to avoid using peak electricity charges. Seems a bit silly to be so penny-pinching on something that's only done every 3 to 6 months.

The car needs to see the bottom end from time to time to make sure everything is calibrated correctly, So run it down under 10% on a day when you can leave it on an AC charger for long enough to let it get to 100% and balance-charge.
 
Rolfe said:
It's in the manual and there is a thread on this specifically. Mainly, nobody is entirely sure whether the long charge has to be done in one continuous charge or whether you can split it to avoid using peak electricity charges. Seems a bit silly to be so penny-pinching on something that's only done every 3 to 6 months.

The car needs to see the bottom end from time to time to make sure everything is calibrated correctly, So run it down under 10% on a day when you can leave it on an AC charger for long enough to let it get to 100% and balance-charge.
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👍 Thank you
 
I did an equalisation charge last weekend. I sussed from the Greener Days forecast and Octopus Agile rates it was going to be a good weekend for cheap electricity due to the wind, so I took it down below 10% and at 8pm Saturday asked the Ohme to add 95% by 12pm Sunday lunchtime. In the end, it only needed 89% and was done by 9am all at 7.5p per kWh.
 

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