charging to 100%

[solos]

I rest my case battery's are made to charge full so i charge always to 100% my Luxury, maybe this will give after more years a little more degradation but cars goes away every 5 years. My iPhone i charge always every day full has the same chemical battery so now 4 years without almost any loss so the car wont have any problem with, they're made for it.

du you mean by the luxury the 64kwh battery ?

 

[Rolfe]

My feeling was simply that the number of times I'd actually benefit from the extra range would be so few that it just wouldn't be worth it. (I also like the simplicity of the SR, and the fact that it doesn't have cobalt in it.)

Sure, I could get all the way to my friends in Halifax on one charge. And the trip to Sussex I'm planning could easily be done with only two stops in an LR (and it would charge faster), whereas prudence really leans to three stops in the SR.

But for me these are exceptional journeys, and I really couldn't justify the LR for two or three (or even four) trips in a year. For people who do trips like this quite frequently though, it's obviously a no-brainer.

 

[PeteC]

Don’t know, I’d have thought that 70% = all cells at 70% charge rather than 70% at full charge. I can confirm my charge to 70 today did a balance at the end, it looks like it anyway from the graph. There must be a reason MG suggest 100 now and again though.

I charged to 80% today on a public charger and the graph form the charge app shows my Trophy balancing at 80%:

 

[AndyL61]

I charged to 80% today on a public charger and the graph form the charge app shows my Trophy balancing at 80%:
View attachment 18800

Yes it will balance at whatever SOC limit you set as long as it is left plugged in and charging. Not sure why MG say to charge to 100% once a month as balancing is achieved at lower SOC.

 

[Rolfe]

I presume it's normal for the kW to go straight up, stay level, then come straight down again, on an AC charger? Not the curve you get with DC charging?

 

[PeteC]

I presume it's normal for the kW to go straight up, stay level, then come straight down again, on an AC charger? Not the curve you get with DC charging?

I would guess so. It's what I've experienced.

 

[Rolfe]

Me too. But doesn't the speed of charging drop off as the car gets close to 100%? I'm slightly confused on this point.

 

[PeteC]

Me too. But doesn't the speed of charging drop off as the car gets close to 100%? I'm slightly confused on this point.

Yes, I believe it does. But in the case I've just shown I was only going to 80% and my Trophy on a quicker charger will still be taking way over 50kW at that percentage, so the measly little 7 and a bit kW this charger was giving was nowhere near what it could take. I don't know what happens if I take it up to 100% as the only time I've done that is when I'm at home and I'm asleep while the car is charging! I have seen the car taking more than 7kW when over 90% on an ultra rapid so if it ever drops below 7kW it will be at the very top end I would imagine.

 

[Rolfe]

I've watched mine charge to 100% on both the granny charger and a type 2 charger, and the charging curve looks like that. On the granny it's about 1.85 Kw level until it gets to 100%, then it drops immediately to 20 watts.

I've looked at my house electricity consumption when the car has been on the granny charger, and it corroborates that. Flat consumption until it's done, then sharp drop (the 20 watts part disappears in among the lights and the computer and whatever).

 

[Tig170]

:... its all quite new for all of us, i have an LFP battery which had degraded 4% : to be honest its a bit more than i was expecting but still all fine & dandy, todate never needed the full 100% range : 10 years time i might be grumpy, but the free electricity over 10 years may well ougtweigh any grumpyness ?

 

[Rolfe]

:... its all quite new for all of us, i have an LFP battery which had degraded 4% : to be honest its a bit more than i was expecting but still all fine & dandy, todate never needed the full 100% range : 10 years time i might be grumpy, but the free electricity over 10 years may well ougtweigh any grumpyness ?

They say you can get degradation quite early, then it settles down and more or less stays that way.

 

[Tig170]

.. at the end of the day - it is what it is - like most of us we have bought the car outright - so will have to accept any further degredation.

 

[Ian Key]

Yes it will balance at whatever SOC limit you set as long as it is left plugged in and charging. Not sure why MG say to charge to 100% once a month as balancing is achieved at lower SOC.

But isn't it only balancing the cells up to the SOC limit you've set so any cell that at 80% is 20% defective never gets balanced to full capacity if the SOC is 80%?

 

[AndyL61]

But isn't it only balancing the cells up to the SOC limit you've set so any cell that at 80% is 20% defective never gets balanced to full capacity if the SOC is 80%?

Maybe that's why you need to charge to 100% occasionally?

 

[tsedge]

We don't know what the BMS is doing at different states of charge, so I think it is easy to say: "look it balances at 80%" but that doesn't mean that 100% balancing isn't needed. There will be a good reason why MG recommend that.

 

[gus]

Interesting, most of my journeys are short distance so I only charge to 80%, I think I have gone to 100% once since I purchased the MG. every time I think I have a long journey coming up (more than 20%) it seems to get cancelled 3 or 4 days before I am due to go, with hindsight I should have purchased the SR but in the previous ICE I was always doing journeys once or twice a week of over a 100 miles and once a month 500 miles return.
will be interesting to see how long the balance charge is next time I do a 100% charge.

 

[AndyL61]

Interesting, most of my journeys are short distance so I only charge to 80%, I think I have gone to 100% once since I purchased the MG. every time I think I have a long journey coming up (more than 20%) it seems to get cancelled 3 or 4 days before I am due to go, with hindsight I should have purchased the SR but in the previous ICE I was always doing journeys once or twice a week of over a 100 miles and once a month 500 miles return.
will be interesting to see how long the balance charge is next time I do a 100% charge.

That's an interesting question . Does balancing less often mean it will take longer to balance when you do ?

 

[Ian Key]

That's an interesting question . Does balancing less often mean it will take longer to balance when you do ?

Good question, and does the number of times you've charged to 80% between 100% balance charges make a difference?

My guess is yes.

 

[lsb777]

The drivers manual states...

Equalisation charging means that after a normal charging process the battery management system will enter a mode where it will attempt to equalise the charge of every battery cell. If an equalisation charge has not been carried out for sometime, the message centre in the instrument pack will display 'Please Slow-charge the Vehicle'.

Manual available here...https://www.mg.co.uk/my-mg/my-mg

 

[gus]

I guess I will find out at some point, last time I hit 100% was last year sometime, so a good 10 months to the best of my knowledge.