Range decrease due to cold weather [merged thread]

[JonnyG]

Well I managed to get 1.2m/kWh over this last two weeks, 67 miles travelled and 55.5kWh put in.
Pre heated every morning on high, heater on at 27C and short 2.5 mile each way journeys once a day.
I'm beginning to wonder why I traded in my ZS for this, it's costing me more per mile than my old Prius was and that's charging at home on a 20p/kWh EV tariff.

TBF last week was very cold and you took the choice to preheat etc for short journeys (as I do) and take the hit on efficiency. But that's just one cold week with many short journeys made in it. Look at the bigger picture over a year as a whole and I'm sure things will improve dramatically ???

Here's my summary chart (1st left one) as I choice to keep warm and toasty :- 38% of power went on the HVAC !! and Intelligent Battery Heating (as I turned ths on due to negative -c temps).

At 9c temp my graph is completely different and much more efficient (2nd graph)

 

[Kithmo]

TBF last week was very cold and you took the choice to preheat etc for short journeys (as I do) and take the hit on efficiency. But that's just one cold week with many short journeys made in it. Look at the bigger picture over a year as a whole and I'm sure things will improve dramatically ???

Here's my summary chart (1st left one) as I choice to keep warm and toasty :- 38% of power went on the HVAC !! and Intelligent Battery Heating (as I turned ths on due to negative -c temps).

At 9c temp my graph is completely different and much more efficient (2nd graph)

I think there's something seriously wrong with mine though. The summary chart this morning showed 50% AC and 50% driving and I didn't have the heater on.
I've noticed in the past that when I'm sat waiting in the car with the heater on the m/kWh drops as it's using the battery. This morning it was dropping without the heater on. I had the seat and steering wheel heaters on so I turned them off and it was still dropping.

 

[Anon70]

TBF last week was very cold and you took the choice to preheat etc for short journeys (as I do) and take the hit on efficiency. But that's just one cold week with many short journeys made in it. Look at the bigger picture over a year as a whole and I'm sure things will improve dramatically ???

Here's my summary chart (1st left one) as I choice to keep warm and toasty :- 38% of power went on the HVAC !! and Intelligent Battery Heating (as I turned ths on due to negative -c temps).

At 9c temp my graph is completely different and much more efficient (2nd graph)

Interesting that the scale on the Y axis is different for each graph and the peak efficiency of the car is reporting up to 15 miles/kWh (I assume this is during a period of regen)

 

[Archev]

With respect, is it worth wasting all that energy for such a short journey? I appreciate if the car windscreen is iced up then it's a great way to defrost, but then 27c as well. The consumption chart must be heavily swayed towards HVAC compared to driving. I find the seats & steering wheel warm up really quick and don't have the same battery drain so I'd put up with it for 2.5 miles personally.

Of course it isn’t it’s absolutely ridiculous - throw me the keys and I’ll go (the long way round ?)

 

[Headgas1]

Well I managed to get 1.2m/kWh over this last two weeks, 67 miles travelled and 55.5kWh put in.
Pre heated every morning on high, heater on at 27C and short 2.5 mile each way journeys once a day.
I'm beginning to wonder why I traded in my ZS for this, it's costing me more per mile than my old Prius was and that's charging at home on a 20p/kWh EV ta

I think there's something seriously wrong with mine though. The summary chart this morning showed 50% AC and 50% driving and I didn't have the heater on.
I've noticed in the past that when I'm sat waiting in the car with the heater on the m/kWh drops as it's using the battery. This morning it was dropping without the heater on. I had the seat and steering wheel heaters on so I turned them off and it was still dropping.

Have you got the intelligent battery heating on ? would that account for this maybe !!! aren’t the the heated seats and steering wheel powered by the 12v battery so that wouldn’t cause the drop maybe a trip to the dealership is on the books if the car can reach it without running out of juice ????

 

[Rolfe]

I don't see how any of these things, or even all of them, can account for what he's reporting. There's something wrong, and it needs looking at, not trading in!

 

[Headgas1]

I don't see how any of these things, or even all of them, can account for what he's reporting. There's something wrong, and it needs looking at, not trading i

Yep I agree who said about trading it in ???

 

[Rolfe]

Kithmo, in other threads. He was talking about changing the car because of the abysmal range he's getting.

 

[Tig170]

In winter go with your battery %, as miles left, and in the summer go with twice you battery %, as miles left. All extreme : but thats what you should expect something in this range given all circumstances (aside from V2L) - We have a 50kWh battery, so in winter never had <100miles yet, but close, and in summer >200miles is close as best.

 

[Rolfe]

That's roughly what I do, but although on occasion the former is true in winter it's never true for long enough to lead to me only getting 100 miles from 100% charge, even in the SR.

 

[Ian Key]

I think there's something seriously wrong with mine though. The summary chart this morning showed 50% AC and 50% driving and I didn't have the heater on.
I've noticed in the past that when I'm sat waiting in the car with the heater on the m/kWh drops as it's using the battery. This morning it was dropping without the heater on. I had the seat and steering wheel heaters on so I turned them off and it was still dropping.

Sorry if I've missed it but just to eliminate one possibility. You have taken the it down to below 10% charge and recharged the car back up to 100% on an AC charger and left it do a balance charge?

 

[K15DNS]

Yes all reset no heating on, and struggling to get over 40 mph, AA out now collecting the car

 

[Anon70]

Here are some stats on the 3 battery sizes (taken from the EV database pages) for the MG4 across different efficiencies you can use this as a rough ready reckoner for % charge to miles achievable. To get quoted WLTP figures the car needs to return over 4 miles per kWh

 

[K15DNS]

Some good reading there thank you, I can get the higher range in the summer time no problem, just getting 88 miles on over 3kWh must be wrong looking at the stats above

 

[Kithmo]

Sorry if I've missed it but just to eliminate one possibility. You have taken the it down to below 10% charge and recharged the car back up to 100% on an AC charger and left it do a balance charge?

Not to 10% but IIRC it was about 18% then up to 100% AC and balance.

 

[JonnyG]

Here are some stats on the 3 battery sizes (taken from the EV database pages) for the MG4 across different efficiencies you can use this as a rough ready reckoner for % charge to miles achievable. To get quoted WLTP figures the car needs to return over 4 miles per kWh

Thanks for posting those ?

Could I suggest a 2.5mls/kwh would be helpful too, as perhaps the worst case in Winter ? ?

 

[Rolfe]

You could try going right down to 10% and then one single AC charge to 100% and balance, but honestly, I think there's more wrong than that. Have you spoken to your dealer about it?

 

[Rolfe]

Some good reading there thank you, I can get the higher range in the summer time no problem, just getting 88 miles on over 3kWh must be wrong looking at the stats above

Absolutely wrong. I do not have the lightest right foot but the lowest app estimate I've seen at 100% charge has been 145 miles. After running around with a series of 3-mile journeys with pre-heating and the heater on full when driving, I'm seeing 36% battery estimating 41 miles range. That scales up to about 114 miles for the full battery. I would struggle to drive the car any less economically than I have been driving it.

Also, I don't think I saw 3 miles/kWh at all during the past week. Always less than that. And yet still I have reasonable range.

 

[Kithmo]

You could try going right down to 10% and then one single AC charge to 100% and balance, but honestly, I think there's more wrong than that. Have you spoken to your dealer about it?

Not yet, I'm running it a few days without the heater or seat and steering wheel heaters while the weather's a bit warmer (8C) to see what I get.
I got 3.9 m/kWh today on a bit longer run, 5 miles each way with no heat etc. and the m/kWh didn't drop as I sat in the car on my drive at the end of the journey. I suspect the dealer will say there's nothing wrong or not be able to duplicate the problem.
I was thinking maybe the battery heater was on even though it was showing as off and fresh start has now turned it off.
I'm going to monitor this charge to see what happens and let it run right down, then maybe contact the dealer if there's no improvement.

 

[Rolfe]

I really hope it's something as simple as that. I've been running around being entirely careless about having the heating on and pre-heating and going short journeys in sub-zero temperatures and I haven't had any nasty surprises about the range at all.