MG5 long range 71 plate SOH After 62000 miles. Do you have any figures?

[Pebblefeline]

It’s all a bit random
I am at 79 percent charged overnight and it says 244 which is patently unachievable
But I did a reset 150 miles ago

Last week the same charge was about 199 pre reset.

I think the software can be a little misleading.

This just might eliminate another possible gremlin.

 

[ayres]

I agree the range is all a bit random but the 93% figure for battery degradation from service is the worrying bit.

 

[Pebblefeline]

Also bear in mind the usable capacity is 57 kWh roughly not the full 61.

That would be 57*3.9 is 222 miles

I hear your worry, I worry in a similar way

There have been a few cases where the soh reading at service is patently wrong and returns a low number. (I am pretty sure they were on this forum)

I think you may have been given a bum reading possibly

This is the thread from the zs forum

Post your MG ZS EV battery SOH data please

It was my missus's choice really to change the car. We're both retired & don't use the car every day. She misses a reversing camera & most of all the heated seat which are not on this Gen 1 excite model. I forgot that there is no reverse camera and bits like heated seats on the Excite model...

www.mgevs.com

 

[MickeySw]

I agree the range is all a bit random but the 93% figure for battery degradation from service is the worrying bit.

Your SoH given after the service is in line with the range drop, therefore the car calculates range based on 93% figure, like it or not.

You can balance all you want, it won’t affect SoH unfortunately. @Gomev is correct, the weakest cell defines the complete pack and if that’s the case the only solution is to replace it.

Problem is MG won’t go near it as SoH hasn’t dropped below 70% and even if it had, they would replace the whole pack.

The only thing you can do (apart from grin and bear it) is a calibration charge, meaning you need to discharge below 10%, then AC charge in one go to 100% and leave it plugged in to complete balancing.

This will re-calculate the SoH and correct the value if it’s out. Might be a good idea to do a hard reset before you start all this.

 

[ayres]

Your SoH given after the service is in line with the range drop, therefore the car calculates range based on 93% figure, like it or not.

You can balance all you want, it won’t affect SoH unfortunately. @Gomev is correct, the weakest cell defines the complete pack and if that’s the case the only solution is to replace it.

Problem is MG won’t go near it as SoH hasn’t dropped below 70% and even if it had, they would replace the whole pack.

The only thing you can do (apart from grin and bear it) is a calibration charge, meaning you need to discharge below 10%, then AC charge in one go to 100% and leave it plugged in to complete balancing.

This will re-calculate the SoH and correct the value if it’s out. Might be a good idea to do a hard reset before you start all this.

The balance charge etc and bits I have been told to do because others disbelieved the soh. I fully believe it. Just very disapointed that it’s dropped so much so early when others who rapid charge regularly etc have not seen a drop like that.

 

[MickeySw]

The balance charge etc and bits I have been told to do because others disbelieved the soh. I fully believe it. Just very disapointed that it’s dropped so much so early when others who rapid charge regularly etc have not seen a drop like that.

I’m not convinced it’s correct for the very reasons you mentioned.

 

[5teep]

The balance charge etc and bits I have been told to do because others disbelieved the soh. I fully believe it. Just very disapointed that it’s dropped so much so early when others who rapid charge regularly etc have not seen a drop like that.

My own standard range was still at 98% at around the same mileage as yours. Yours is significantly less, so it's worth doing everything you can to check that it's accurate and if so maybe get the dealer to check it out? (albeit not under warranty as you said above)

 

[Verdigris]

I did my balance charge, today, and the SOH is still 96.45%. The worst cell was 0.02V out, most were 0.01V out, or spot on. Resistance was 1.33 ohms. It should be below 10% charge after taking for a service, so I'll do a one-shot recalibration charge then.

 

[ayres]

How did you get your figures?

 

[Verdigris]

From Car Scanner via OBD2 port.

 

[ayres]

Think I need to order an obd2 reader. Is there a recommended 1?

 

[Coulomb]

Which with that in mind should be 234 not 220 miles.

I would be cautious about making any battery health assumptions from the estimated range remaining (guess-o-meter).

On my ZS EV, estimated range drops 5% if I have the air on, even if not heating or cooling, just the blower fan. I note that 220 ÷ 0.95 = 232.

Resistance was 1.33 ohms.

That figure can't be right. At s moderate 100A draw, the battery voltage would drop 133V, a third of the total voltage. It would also be dissipating 13kW. Hopefully the other numbers can be trusted, but it's possible that the app isn't interpreting the CAN bus messages correctly. Perhaps it has the wrong vehicle profile set.

Perhaps try the eZS app, if you have an Android phone or pad. It's designed for the ZS EV, but major items like SoH probably use the same PID and data format, i.e. you should get a valid reading of State of Health at least.

 

[ayres]

I would be cautious about making any battery health assumptions from the estimated range remaining (guess-o
On my ZS EV, estimated range drops 5% if I have the air on, even if not heating or cooling, just the blower fan. I note that 220 ÷ 0.95 = 232.

I would be cautious about making any battery health assumptions from the estimated range remaining (guess-o-meter).

On my ZS EV, estimated range drops 5% if I have the air on, even if not heating or cooling, just the blower fan. I note that 220 ÷ 0.95 = 232.

The battery drop is from the service and them telling me it has dropped to 93%. The reset g o m just agrees with what they have said.

 

[Gomev]

I would be cautious about making any battery health assumptions from the estimated range remaining (guess-o-meter).

...

If you do a reset on the accumulated trip when at 100% and balanced, in Ready and Normal mode, and with everything else turned off such as heat/AC, it indicates the SOH quite well by the range indicated. It may not be totally 100% to 3 decimal points but it is very close. The GOM will read as a comparison to WLTP for your model. So for a SE model 250 miles WLTP in UK, if it shows 245 when the above actions have been performed, SOH is 98%.
If you know your SOH try it. It is a simple no tools required method.

 

[ayres]

Full balance charge last night from 9%to 100 and reset again. Range is indeed reduced to 233 on gom. I reckon that’s down to a real world range of under 200miles now. And in winter may struggle to make my regular journey back to my mums without stopping. Very poor result.

 

[Gomev]

View attachment 27259Full balance charge last night from 9%to 100 and reset again. Range is indeed reduced to 233 on gom. I reckon that’s down to a real world range of under 200miles now. And in winter may struggle to make my regular journey back to my mums without stopping. Very poor result.

That does tally with what your were told SOH at service, 93% (233/250)*100 = 93.2.
It sounds bad but in reality it's a loss of just 17 miles out of 250. Unlike an ICE there is no loss of power though.
I would imagine you are at the bottom of the steep decline and it should hold around that for a good while now. As others have said there is a steep decline in the first few years and then a levelling off. ?
Keep up with the regular balancing/calibration.

 

[Caramaddy]

A very interesting thread for a newbie.

 

[MickeySw]

Very poor result.

Not much consolation but once you start comparing there are always going to outliers, some will be better some worse than the average.

EV manufacturers have covered themselves for this very eventuality and MG allow for a generous 30% degradation before taking action.

This is actually a vast improvement compared to 1st gen EVs that had no guaranteed capacity within the battery warranty period.

 

[Verdigris]

And unlike an ICE vehicle, there may be a decrease in range but power will barely be diminished.

 

[Pebblefeline]

My soh has been doing an odd thing. At 9k it was 99.2
Then it suddenly dropped to 97.2 and a thousand miles later its 96.7 at 15500 miles

Is this likely to be a read error on the obd (I use a Carly adaptor with car scanner) or do the batteries degrade like this?

I am not overly worried as long as it stabilises if it keeps dropping like this it could be an issue. I mostly ac charge with a dc charge about twice a month. I do about 2000 miles a month.

I keep the cells balanced monthly the voltage differences between max and min are .01 or less

The voltage at 100 charge is about 405v

Anything I should look out for? Or is the soh generally a bit pointless to worry about?