Battery Operation Issues MG5 EV SW

DRPAM

Novice Member
I have just (5 weeks ago) bought an MG5 EV SW, my first electric vehicle. I have charged it mainly with the 3 pin 'residential' charger, plus a couple of times at supermarket/garage. My issue relates to sudden changes in miles left on the battery (range) in relation % charge left. I have had three occasions when the miles have suddenly, literally in a second, dropped (e.g. 144 to 129) with no change to % charge left in battery according to the display. Not a major problem, perhaps, until suddenly had to make a round trip of 38 miles in the evening when battery was at 25% with 50 mile range shown on display. After about 15 miles of trip, the range dropped suddenly from 37 miles to 22 miles and then reaching my stop and turn round point was on 8% and range only16 miles - so there was not enough to get home. I found a 7kw charge point at a garage and charged for an hour up to 21%, fortunately it was not snowing when I walked around, but got home with only 6% and 12 miles range left, after warnings about 'aggressive driving' and a speed limited to 50 - I had done 55 max on way home! I have contacted the MG garage where I bought car and they say it sounds like a battery problem, but they are not certain as mine is only the second EV they have sold! However they say will check it, but because of COVID can only do this in 10 days time. However, is this normal?
 

booyaka

Moderator
As with any electric car - the actual "range" of the car is affected by all manner of things.

Outside temp, wind, rain, internal heating, A/C, speed, uphill/downhill etc etc.

I know from my own experience that the quote "range" on my Tesla M3 is nowhere near the "miles" it displays (I have % shown, never the miles as it's pointless)

So I know in the winter time I will probably get around 60% efficency (i.e only 60% of the "Rated" miles) due to the above factors.

In the summer - that goes up to around 80%.......

It's one of the things with electric vehicles - the rated miles is never real world miles.....There are so many factors that affect the distance you drive.

I'm not familiar with the MG display/ratings etc - but it sounds like a fairly standard situation with battery cars.
 

John7

Well-known Member
Sorry, I don't know the answer to your question, I hope the MG garage can sort the issue for you.

This is what spooks me about pure electric vehicles. Having to wait an hour to put in a sufficient charge to complete a 38 mile round trip is unsettling. I'll stick with my Hybrid thanks!
 

LV426

Administrator
Staff member
I can't speak for the MG but based on my (Hyundai) experience, the range to empty is always just a calculated estimate based on:
  • recent driving pattern/style. Spend a few weeks poodling around local areas at lowish speeds with the heat/aircon off and it will estimate a higher value. Turn comfort on and hammer along a motorway/A road and it will drop. And vice versa.
  • Present power demand.

"Sudden" changes like this may be accounted for by the comfort thermostat turning the heat/air on and off to maintain cabin temperature.

The trick is to always either take or make charging opportunities; even 30 minutes while in a supermarket isn't wasted (unless it was already full) and adds range and/or saves 30 minutes next time. And if you are short on range, turn all the high power ancillaries off.
 

DRPAM

Novice Member
As with any electric car - the actual "range" of the car is affected by all manner of things.

Outside temp, wind, rain, internal heating, A/C, speed, uphill/downhill etc etc.

I know from my own experience that the quote "range" on my Tesla M3 is nowhere near the "miles" it displays (I have % shown, never the miles as it's pointless)

So I know in the winter time I will probably get around 60% efficency (i.e only 60% of the "Rated" miles) due to the above factors.

In the summer - that goes up to around 80%.......

It's one of the things with electric vehicles - the rated miles is never real world miles.....There are so many factors that affect the distance you drive.

I'm not familiar with the MG display/ratings etc - but it sounds like a fairly standard situation with battery cars.
Many thanks for your response It was certainly cold and the heating was on high on the round trip, but no hills as I am in Norfolk.! In future, I will look harder at the % battery level! However other than occasions I mentioned, there seems to have been a close link between range and charge in that 1% = 2miles has been common for most journeys. I have also seen on a number of EV sites that it is best to keep the charge between 20% and 80%. However, the MG garage has said they would always have it as close to 100% as possible and also not to think of the car as having quite a few miles left when the equivalent of the yellow light comes on in a petrol/diesel vehicle fuel gauge. I think part of the problem here is also that due to COVID the garage has been unable to give more info. on what to expect from the EV.!
 

DRPAM

Novice Member
I can't speak for the MG but based on my (Hyundai) experience, the range to empty is always just a calculated estimate based on:
  • recent driving pattern/style. Spend a few weeks poodling around local areas at lowish speeds with the heat/aircon off and it will estimate a higher value. Turn comfort on and hammer along a motorway/A road and it will drop. And vice versa.
  • Present power demand.

"Sudden" changes like this may be accounted for by the comfort thermostat turning the heat/air on and off to maintain cabin temperature.

The trick is to always either take or make charging opportunities; even 30 minutes while in a supermarket isn't wasted (unless it was already full) and adds range and/or saves 30 minutes next time. And if you are short on range, turn all the high power ancillaries off.
Many thanks. I live in a rural area with relatively few charging points nearby, so have had to rely largely on home charging, but the message seems to be to keep a good charge in the battery at all times and not get caught out by 'an emergency'. Also it seems that travelling at 50-60 (no motorways in Norfolk) uses quite a lot of battery and is less efficient than slow stop/start driving, which is counterintuitive re petrol/diesel vehicles. I think quite a lot of power was also being used up via heating and lights in my 'problem' journey. At least yours and other responses suggest that there is not a big problem!
 

DRPAM

Novice Member
Sorry, I don't know the answer to your question, I hope the MG garage can sort the issue for you.

This is what spooks me about pure electric vehicles. Having to wait an hour to put in a sufficient charge to complete a 38 mile round trip is unsettling. I'll stick with my Hybrid thanks!
Thanks very much for your responses. A couple of other responses have suggested this is what to expect! At least it seems I don't have a big problem with the battery!
 

booyaka

Moderator
Thanks very much for your responses. A couple of other responses have suggested this is what to expect! At least it seems I don't have a big problem with the battery!
Sorry, I don't know the answer to your question, I hope the MG garage can sort the issue for you.

This is what spooks me about pure electric vehicles. Having to wait an hour to put in a sufficient charge to complete a 38 mile round trip is unsettling. I'll stick with my Hybrid thanks!

I think to be fair - a 7kw charger isn't really meant for a "quick" top up. It's a standard home charger/visiting tesco charger.

22kw/50kw rapids are more common public now which means much quicker delivery.

I think the OP's situation was more desperation than anything.
 

LV426

Administrator
Staff member
I think quite a lot of power was also being used up via heating and lights in my 'problem' journey. At least yours and other responses suggest that there is not a big problem!

Heating will be the culprit, I suspect. Unlike an ICE where the heat comes from the engine so is "free" but for the fan itself, there is practically no "waste" heat. So it all has to be provided. I'm guessing (without knowing) that the MG has a conventional electric heater which will probably draw a kW or two off the main power. Hyundai have an air source heat pump which is way, way more efficient, but it still has a notable effect on range.

the message seems to be to keep a good charge in the battery at all times
Absolutely. Plugged in whenever near a point (whether at home or elsewhere). It becomes second nature in time.
 

IronGiant

Moderator
I think you are right Nigel, compared with the Leaf the MG is much "thirstier" when it comes to cabin comfort. It's also quite a basic system, ie not true climate control so that can't help.
I just checked and ours has 73 miles left in the tank at present but if I power off cabin control that jumps to 81.
 

Delvey

Distinguished Member
Additionally batteries don't like the cold. Not sure if the MG has a battery heat system but when it drops close to freezing a battery doesn't like it. Add in additional heating etc and range will drop. This is one of the reasons we've not bought an EV. The misses does 100 miles a day and you are not guaranteed that in winter with hill driving unless you spend £30,000 plus
 

IronGiant

Moderator
Not sure if the MG has a battery heat system
Jury seems to be out on that one. It doesn't have it's own heater, but it might circulate warm air from the HVAC if on. It does have active cooling.
 

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