MG ZS EV Temperature and drastic drop in miles per kWh

[Delboy102000]

That's a battery heater

A heat pump recovers heat the ambient air**, then effectively uses the AC in reverse to extract that warmth, it's approximately 4x more efficient than resistive heating. Just like air source heating, in the home

This is my current based on about 2000 miles with average of 3.7 Mp kw

** at least, this is what I read this weekend, I'd previously assumed that a heat pump recovers any heat generated by the cars motor/controller

 

[Delboy102000]

This is my screenshot

 

[Bodgerx]

That’s a very interesting point and perfectly relevant. We seldom look at the complete picture when calculating costs (particularly cost per mile). A reduced off-peak cost nearly always comes with a higher peak cost as you mention. The financial impact does depend on how much off peak v peak that you consume too.

In the current market on an EV tariff you typically can pay about 10p/KwHr more on your peak rate compared to a tariff without the benefit of EV off peak discounted rate, in order to get the convenience of that cheaper off peak tariff. Although who knows how this figure will continue to fluctuate…

I use around 3000kwhr a year peak so I’m paying around £300 extra on my ‘home’ usage to subsidise my off peak EV charging which uses around 4000kwhr a Year at about 12p/KwHr.

I travel about 15000 miles year = approximately 3p/mile - if you add in the extra that I need to pay off peak to get the cheaper peak tariff (£300) - that increases to about 5/mile (so it not far off doubles the cost in my case). The standing charges are very similar on both types of tariff.

Off course if I charged my EV using peak rates it would cost around three times more and instead of around £480 a year more like £1500 a year, but that’s for me and not everyone.
If you’re travelling relatively short distances a Year (you mention 7500miles), or can’t charge using a competitive off peak tariff, then the current financial benefits of an EV are really not that great any more (this has been done to death elsewhere).

Still the most economic way to go for me is a cheaper off peak tariff, but if that starts to creep up it will soon become less relevant.
It’s a good point that you make.

The economic benefits were never going to last.

You have to be in it for more that, as it won't be too long before it's the only type of car you can buy.

 

[AK OK]

The economic benefits were never going to last.

You have to be in it for more that, as it won't be too long before it's the only type of car you can buy.

*New car...

 

[Lovemyev]

Is 199 miles after you have reset the trips? (I seem to remember you saying that you reset the trips each charge) If it is, that suggests that the GOM does take temperature into account, rather than purely using previous driving results

I've just charged mine to 90%, the app is showing a predicted range of 200 miles, but I haven't reset the trip recently and I've been using the remote heating a lot for short journeys, so it's no surprise that my range is down

Your right !.
Both trips are both reset before every home recharge ( if I remember to do it ).
This is another reason why I like to carry out this routine on a regular basis.
If you’re going to study things that affect your various things like range / driving styles / different diving modes / charging level SOC / temperature change affects / characteristics etc.
Then you need to offer a level playing field in order to be more accurate in your findings.
Example :- By following the same routine from March 2022 until now, I have constantly see a predicted range of 212 miles at 80% SOC.
Now at temperatures of -2 degrees I am witnessing a predicted range of 199 miles for the same 80% SOC.
So, what has changed here folks ?????.
Well, I am pretty comfortable in coming to the conclusion, that is either one of these three factors.
( 1 ) Ambient freezing temperatures of -2 degrees, is responsible for this drop.
( 2 ) A possible battery imbalance ( although unlikely as it has never presented this way before the colder snap ).
( 3 ) Battery degradation.
When the ambient temperature rises again, this will hopefully prove that ONE of the above theories is correct.
For me it has just become a bad habit really, I got into this when we had issues with our Gen 1 ZS EV.
Therefore I have just continued to monitor things on our Gen 2 face lift LR at a distance.
Following this pattern makes identifying potential issues and any changes very easy to to spot.

 

[Bodgerx]

*New car...

True, but it's probably not too far past the 2030 deadline before the price of used ICE cars take a nose dive, as tax disincentives start and they start to become close to worthless.

 

[Bodgerx]

Your right !.
Both trips are both reset before every home recharge ( if I remember to do it ).
This is another reason why I like to carry out this routine on a regular basis.
If you’re going to study things that affect your various things like range / driving styles / different diving modes / charging level SOC / temperature change affects / characteristics etc.
Then you need to offer a level playing field in order to be more accurate in your findings.
Example :- By following the same routine from March 2022 until now, I have constantly see a predicted range of 212 miles at 80% SOC.
Now at temperatures of -2 degrees I am witnessing a predicted range of 199 miles for the same 80% SOC.
So, what has changed here folks ?????.
Well, I am pretty comfortable in coming to the conclusion, that is either one of these three factors.
( 1 ) Ambient freezing temperatures of -2 degrees, is responsible for this drop.
( 2 ) A possible battery imbalance ( although unlikely as it has never presented this way before the colder snap ).
( 3 ) Battery degradation.
When the ambient temperature rises again, this will hopefully prove that ONE of the above theories is correct.
For me it has just become a bad habit really, I got into this when we had issues with our Gen 1 ZS EV.
Therefore I have just continued to monitor things on our Gen 2 face lift LR at a distance.
Following this pattern makes identifying potential issues and any changes very easy to to spot.

The change is that you are running a power hungry resistive heater to run the cabin heat + battery heating + front camera heater etc. etc.

 

[Lovemyev]

The change is that you are running a power hungry resistive heater to run the cabin heat + battery heating + front camera heater etc. etc.

Not when you have reset both of the trips.
As this has removed all of the historical data stored by the car, with trips reset, your should see the same factory WLTP figure, as the predicted range.

 

[Merry]

One thing I believe many people are kidding themselves over is when they say , on my tariff at night it only costs me x p per kw. The trouble is that all of the household rate is surcharged so if you do 3500 units per annum without the car which is surcharged at 10p per kilowatt the perceived saving is nowhere near the reality as you pay more for all other electricity.
Therefore for simplicity if you do 7500 miles which is about 2400 kw used you need to take into account the surcharge on you regular offtake and add it to get true cost. Also charging at night is not always convenient especially if the nighttime slot only gives you time to put in 30 or 35 kw per session.
Each time I have looked I have struggled to see the benefit in cost or convenience terms

It depends. I don't charge my MG at home, it gets charged for free at work, however my wife's Outlander does. Despite it having a tiny wee battery and taking, on average, about 6kwh a day it accounts for quite a bit of our usage.

We jumped on the Octopus GO Faster tariff before it went and can load shift the washer and dryer too, off the back of all that we're averaging 20p a kwh, from a 39p peak and 8.25p off peak rate.

So basically you'd have to be doing very low milage with your ev for it not to make sense.

With regard range, yes its hopeless at the moment. Over last 3 days it's been a struggle to get over 2.5mls/kwh.

It was the same last year....

 

[Striker]

Your right !.
Both trips are both reset before every home recharge ( if I remember to do it ).
This is another reason why I like to carry out this routine on a regular basis.
If you’re going to study things that affect your various things like range / driving styles / different diving modes / charging level SOC / temperature change affects / characteristics etc.
Then you need to offer a level playing field in order to be more accurate in your findings.
Example :- By following the same routine from March 2022 until now, I have constantly see a predicted range of 212 miles at 80% SOC.
Now at temperatures of -2 degrees I am witnessing a predicted range of 199 miles for the same 80% SOC.
So, what has changed here folks ?????.
Well, I am pretty comfortable in coming to the conclusion, that is either one of these three factors.
( 1 ) Ambient freezing temperatures of -2 degrees, is responsible for this drop.
( 2 ) A possible battery imbalance ( although unlikely as it has never presented this way before the colder snap ).
( 3 ) Battery degradation.
When the ambient temperature rises again, this will hopefully prove that ONE of the above theories is correct.
For me it has just become a bad habit really, I got into this when we had issues with our Gen 1 ZS EV.
Therefore I have just continued to monitor things on our Gen 2 face lift LR at a distance.
Following this pattern makes identifying potential issues and any changes very easy to to spot.

Interesting, thanks for your info, and dogged routine

I’d hope that the GOM calcs included ambient temperatures, but I’d not seen any evidence

Now, the next thing that I want to get my head around, is how pre heating the cabin affects the GOM, if at all?. The m/kWh on the journey after heating, doesn’t seem to include the energy used to heat. The GOM doesn’t seem to drop, but the actual mileage achieved obviously drops with the energy used . I guess that there’s only so much that the GOM can cover

 

[jamie07051975]

One thing I believe many people are kidding themselves over is when they say , on my tariff at night it only costs me x p per kw. The trouble is that all of the household rate is surcharged so if you do 3500 units per annum without the car which is surcharged at 10p per kilowatt the perceived saving is nowhere near the reality as you pay more for all other electricity.
Therefore for simplicity if you do 7500 miles which is about 2400 kw used you need to take into account the surcharge on you regular offtake and add it to get true cost. Also charging at night is not always convenient especially if the nighttime slot only gives you time to put in 30 or 35 kw per session.
Each time I have looked I have struggled to see the benefit in cost or convenience terms

I looked at that and we're getting home batteries fitted which would charge at the cheaper rate and then the house will use them throughout the day.

We may look at solar down the road but not worth it at present.

 

[N2STY]

@Striker
The other morning -4 thick frost car was plugged in and at set charge I remote cabin heating and range dropped the normal heating on but after the 10 minutes it's off right l looked on CCTV still a bit of frost on roof so went to run again and before I did I noticed original range was up 15 to 20 miles up than before 1st heating session so the gom must take battery temp in to consideration not just ambient temperature

 

[Redoralive]

Mine is all over the shop. The first proper cold morning a few weeks back, car started dropping 1% per mile. Had to rapid charge before it started behaving again. The other day the miles per kw started climbing during the first few miles to 5.8 before it remembered which way it was supposed to go. Also noticed the kers is weaker when cold. It did say -20% at one point but the amps were pretty low. Range estimate coincides with 2.5 - 3 miles per kwh but the misses did get confused and leave the defrost setting on.

 

[Bodgerx]

Not when you have reset both of the trips.
As this has removed all of the historical data stored by the car, with trips reset, your should see the same factory WLTP figure, as the predicted range.

Do that test with the AC set to 20C and then with the AC/ heat off completely.

 

[N2STY]

Ok so I charged my car today to 90% it's finished at 1600 ish now just about to go to work and I noticed battery was charging I think the battery heater switched it's self on I have no timers set

1kw draw for battery heating?

 

[Lovemyev]

Do that test with the AC set to 20C and then with the AC/ heat off completely.

This has absolutely no relevance to be honest in this case ?.
The original question, was about different reports of predicted range after a set SOC in the much colder weather conditions now ?.
OP question - Has your reported / predicted range reduced after the same level of required SOC level ( e.g. 80% ) reporting a less predicted range due to the colder weather conditions ?.
Or something along these lines.
Any reading is taken with both trips reset ( prior to charging ) and without the car in READY mode.
There insuring that there is no HVAC or any other items running in the back ground for that matter, that could corrupt the predicted range figure.
Checking the App is a good way of seeing this, as the car is completely closed down.
On our Trophy LR - charge to 80% SOC and all trips reset and NOTHING turned on, in better weather conditions returns a predicted range of 212 miles.
Same process, now conducting the same test at -2 degrees, the reported range is now at 199 miles of predicted range.
All parameters are the same, except from the weather conditions, which we are not in control over unfortunately.

 

[Bodgerx]

This has absolutely no relevance to be honest in this case ?.
The original question, was about different reports of predicted range after a set SOC in the much colder weather conditions now ?.
OP question - Has your reported / predicted range reduced after the same level of required SOC level ( e.g. 80% ) reporting a less predicted range due to the colder weather conditions ?.
Or something along these lines.
Any reading is taken with both trips reset ( prior to charging ) and without the car in READY mode.
There insuring that there is no HVAC or any other items running in the back ground for that matter, that could corrupt the predicted range figure.
Checking the App is a good way of seeing this, as the car is completely closed down.
On our Trophy LR - charge to 80% SOC and all trips reset and NOTHING turned on, in better weather conditions returns a predicted range of 212 miles.
Same process, now conducting the same test at -2 degrees, the reported range is now at 199 miles of predicted range.
All parameters are the same, except from the weather conditions, which we are not in control over unfortunately.

Part of the cars prediction isn't just past performance, it's what you have enabled disabled. Watch that range change when you change driving mode, for example.

 

[N2STY]

Part of the cars prediction isn't just past performance, it's what you have enabled disabled. Watch that range change when you change driving mode, for example.

I think what @Lovemyev is doing is keeping the base line the same all the time so changes are easier to spot

 

[rpannell]

Has anyone found a way to pre-heat the battery whilst the car is plugged in? On my LR trophy, the battery heating on the app does not work (although sometimes it says 'success') and the only way I can get the battery to heat is with the charger disconnected and the car in 'ready' mode.

 

[Lovemyev]

I think what @Lovemyev is doing is keeping the base line the same all the time so changes are easier to spot

Thank you @N2STY .
I thought I had explained that in detail in the first post, but maybe not well enough .
When making a fair comparison, you need a good known fixed point / baseline ( good word ) to start from, that is what I did with the original ZS EV over two years and 20,000 miles and I and now doing with the facelift model.
Building up a mental portfolio of data is what is going on really.
Sticking with a set of parameters for comparison reasons.