MG4 - Loss of power in cold weather with over 30% battery

[M101]

When i drove to work today i set off with 32% battery and the car had lost most of its power, the acceleration was slow and felt like i had the handbrake on, i was struggling to go over 50mph on the bypass and then struggling to get over 22mph going up a hill in a 30 zone.
Im going to assume that with it being -6 degrees that the car automatically went in to power save mode as it couldn't access all the power in the battery.
Is anyone else having similar issues?

 

[Kamil]

I can only think off battery impacted by weather ( I didn't want to put comment battery frozen)

I am sure pre heating car before journey should solve this issue

 

[siteguru]

SR or LR model? (Different battery compounds)

I had no issues in my SE SR this morning. (Set off with 42% battery SoC, arrived with 38%). That said I did preheat the cabin as it was really cold plus we'd had a dusting of snow.

 

[AdamMGEV]

Lets face it you shouldn't have to pre heat a car for it to work and in Scandinavia dont they have loads of MG EVs'?

 

[Deleted member 9909]

Let's be honest 32% is well within the normal parameters of full operation. Cold batteries should not have such a profound affect. Yes it will have an effect on charge and discharge but this amount? Do you get cold battery warnings in the car? Any driver alerts?

 

[siteguru]

Cabin preheat is a personal comfort thing. Battery preheat is a separate matter.

 

[M101]

mine is an SR, it was absolutely fine yesterday when it had more than 50% battery, and it was also -6 degrees, it even had enough power to spin the rear wheel and drift sideways on to the bypass.
I had preheated the cabin this morning but not the battery.
Im wary about preheating the battery when the battery is low in case i use too much power and then dont have enough to get to work where i can charge for free.

 

[M101]

Let's be honest 32% is well within the normal parameters of full operation. Cold batteries should not have such a profound affect. Yes it will have an effect on charge and discharge but this amount? Do you get cold battery warnings in the car? Any driver alerts?

No warnings or alerts other than "possible icy roads", it was just WAY down on power.

 

[Deleted member 9909]

In this cold weather it would be justified to plug in an active charger (even a granny one) purely to help with the drain from batteries whilst preheating them imo..that is if you can

 

[M101]

In this cold weather it would be justified to plug in an active charger (even a granny one) purely to help with the drain from batteries whilst preheating them imo..that is if you can

Thats good because i only have a granny charger at home, im trying to avoid paying for the electric while i get it free at my workplace, because this was the only reason i bought an EV!

Its currently hooked up to a 7kw charger and i've set it to preheat the battery an hour before i leave work so i will see how much difference it makes.
Although i've never had any power issues with a full battery

 

[Deleted member 9909]

Thats good because i only have a granny charger at home, im trying to avoid paying for the electric while i get it free at my workplace, because this was the only reason i bought an EV!

Its currently hooked up to a 7kw charger and i've set it to preheat the battery an hour before i leave work so i will see how much difference it makes.
Although i've never had any power issues with a full battery

I get the saving pennies thing but sometimes needs must....

 

[MuzGB1970]

I've not pre-heated the battery in this cold weather and the car has not prompted me to do it either, so far not noticed any loss of power. I always use the AC with climate set on 24 degrees and AUTO fan, rear demister is used when necessary. My driving mode is always set to NORMAL with maximum regen, on journeys over about 10-15 miles I'm getting 3.2m/kWh as a minimum and often a little more, compared to 3.7m/kWh back in October. I'm very happy with that return.

I charge at work so when I warm the car in the morning it takes power from the battery, but it doesn't seem to be very much. I've a Trophy so the energy usage chart doesn't show much. I've just done a full charge for the weekend and it's showing 222 miles range.

 

[M101]

my car on average is getting between 2 and 2.5m/kwh, i was able to get 3.5 on a run to Blackpool last weekend but its a very flat run and i was sitting at a constant speed for most of the journey, my 9 mile commute is a mixture of road types with a lot of hills so it not really representative of what its capable of.

I will try pre-heating the battery all next week and see if it improves

 

[bowfer]

Have you seen my post about restricted speed?
I’ve had the car just stop accelerating at 70mph and 60mph, foot to the floor.
Can’t remember what the battery was at for the 70mph incident, but the 60mph incident was around 40%.
I also noticed during the 60mph incident that acceleration up to there was poor.
An MG5 I had a loan of the same day flew up the same road, feeling like it had 50bhp more than mine.
On both occasions I never thought of looking at the power gauge to see what percentage power my foot to the floor was getting, but I will next time.
I’ve documented this with the dealer.
It’s bloody dangerous to have any car decide it’s going to limit your speed without any warning.
I’ve literally never experienced this in any EV before and I’m not going to just live with it.

 

[M101]

Have you seen my post about restricted speed?
I’ve had the car just stop accelerating at 70mph and 60mph, foot to the floor.
Can’t remember what the battery was at for the 70mph incident, but the 60mph incident was around 40%.
I also noticed during the 60mph incident that acceleration up to there was poor.
An MG5 I had a loan of the same day flew up the same road, feeling like it had 50bhp more than mine.
On both occasions I never thought of looking at the power gauge to see what percentage power my foot to the floor was getting, but I will next time.
I’ve documented this with the dealer.
It’s bloody dangerous to have any car decide it’s going to limit your speed without any warning.
I’ve literally never experimented this in any EV before and I’m not going to just live with it.

I have not seen your post but that's exactly what mine did.
the next cold day with a low battery I'm going to do the pre heating and see if that solves the problem.
I wonder if the skate board battery is more susceptible to cold weather because they are closer to the cold ground??

 

[bowfer]

I have not seen your post but that's exactly what mine did.
the next cold day with a low battery I'm going to do the pre heating and see if that solves the problem.
I wonder if the skate board battery is more susceptible to cold weather because they are closer to the cold ground??

FYI I checked the settings of the MG5 and it did not have battery preheat on, neither did my 4.
So two cars from the same maker, same weather conditions, same road.
One flies up it and the other just stops at 60mph.
Both batteries with decent (middling) amounts of charge in them.
Baffling.

If my car does it again it’s going back, I’m not having a car decide what top speed I can do.

 

[Ian Key]

I wonder if the different battery chemistry in the MG4 SE is more susceptible to the cold than the one in the MG5?

 

[SEastEV]

This is concerning. If this is a software glitch/restriction then surely it would affect more people? I really don't like the intermittent random like behaviour of this and other glitches. As an IT professional, it makes me really nervous! Ironically I would feel much more [happier] if these problems affected everyone and then MG would have to act.

 

[Deleted member 9909]

As an ex IT professional I am not concerned myself for exactly the reasons you point out. So far how many forum members have raised it? Not enough to wake me up. Bowfer may have got a Friday car and I do sympathise with his car issues but let's keep it in context surely?

 

[SEastEV]

As an ex IT professional I am not concerned myself for exactly the reasons you point out. So far how many forum members have raised it? Not enough to wake me up. Bowfer may have got a Friday car and I do sympathise with his car issues but let's keep it in context surely?

I sincerely hope you are right. But I also sympathise with Bowfer and Michael who have suffered this anomaly.