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

SAIC = Stupid Arsed Incompetent Corporation?

I'll not lie, but for the 1st time ever I did experience this (13,000 miles, 13 months old) - albeit at 60-70mph - but today all back to normal. (with no further issues, i'm lucky that LKA equals OFF all times) - basic SR version

Tig170 said:

I'll not lie, but for the 1st time ever I did experience this (13,000 miles, 13 months old) - albeit at 60-70mph - but today all back to normal. (with no further issues, i'm lucky that LKA equals OFF all times) - basic SR version

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Then the issue will probably be that you can get updates to fix it but those might well give you LKA defaults to on.

Is this the "Bowfer problem" again? If it is, we're pretty confident that the software update that became available at the end of July fixes it.

M101 said:

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?

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I don't get this, but in my MG4 EV, every single time the battery drops to 15%, I get a warning about power and I cannot accelerate. This is so dangerous, imagine if I was merging onto a motorway or overtaking

Richard MG4 EV said:

I don't get this, but in my MG4 EV, every single time the battery drops to 15%, I get a warning about power and I cannot accelerate. This is so dangerous, imagine if I was merging onto a motorway or overtaking

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Well mine is a sack of shit lemon and its full of problems since it left the factory in China. I should have rejected it when i first picked it up because no update MG has ever done has made any difference and it still has power loss issues below 50% battery even when its not that cold!

Needless to say, i cant wait to hand back the keys and i will NEVER go near an MG dealership again.

M101 said:

Well mine is a sack of shit lemon and its full of problems since it left the factory in China. I should have rejected it when I first picked it up because no update MG has ever done has made any difference and it still has power loss issues below 50% battery even when it's not that cold!

Needless to say, I cant wait to hand back the keys and I will NEVER go near an MG dealership again.

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That does sound like the Bowfer problem from 2022 and if they can't fix it in 2024 you're well rid of it.

Richard MG4 EV said:

I don't get this, but in my MG4 EV, every single time the battery drops to 15%, I get a warning about power and I cannot accelerate. This is so dangerous, imagine if I was merging onto a motorway or overtaking

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That is a fault. In the summer my car was overtaking at 80 at 5% battery. Even in winter I only noticed a slight loss of power climbing a fairly steep hill at 12%. I've been very pleased with the car's willingness to trust me that I know where the next charge is coming from and we'll be fine.

Check the thread below folks, hopefully there’s some info in there.

I’ve not had my MG4 long but I believe when the high voltage battery gets low you get a message prompting you to go into Energy Saving Mode (I think when it gets to 10%) I might be wrong on this

Hope you get it sorted.

Rolfe said:

That does sound like the Bowfer problem from 2022 and if they can't fix it in 2024 you're well rid of it.

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Even if it didn't have the power issue, I'd still be glad to see the back of it. The build quality is quite poor for the price, with my car developing a lot of creaks and rattles by the time it had only done 6000 miles, the driver seat started creaking badly after a couple of hundred miles, and now something is knocking on the left rear corner.
I actually dont think I will get another EV because the cost to run this is almost the same as running a petrol car with none of the convenience of quick filling and full power from full to empty, the free charging at my work is getting harder as more people gets EVs so soon I will be paying petrol prices for 12 hours of charging for a shit range than will never get close to the claimed range.

If you can't charge at home it's an issue, for sure. But you do seem to have been sold a lemon.

Adam C said:

Check the thread below folks, hopefully there’s some info in there.

I’ve not had my MG4 long but I believe when the high voltage battery gets low you get a message prompting you to go into Energy Saving Mode (I think when it gets to 10%) I might be wrong on this

Hope you get it sorted.

MG4 losing power

Hey. I have a MG4 SE. The car has been idle since saturday. When I started to drive today it gave 100% power up to about 50-60 kmph and then it dropped down to 56% power. Battery was around 76%. After driving about 10 min it could give 100% at 120 kmph. It is -5c outside. Does the battery...

www.mgevs.com

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Yes, that's right. I find that when I tell the car not to go into energy saving mode it trusts me. Got home on 4% once with no loss of power. (In summer.)

Rolfe said:

If you can't charge at home it's an issue, for sure. But you do seem to have been sold a lemon.

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I can charge at home and it's not very good value for money with the amount it costs to the distance the car will travel on that charge because I get about 100 miles in winter and 140 in summer at a charging cost of about £16. My WRX can almost do that many miles off £20 of fuel. Which just proves how expensive EVs actually are

The range of most EVs is piss poor at the best of times, and the only ones with good range are the ones with batteries so big that the car weights over 2.5 tons and costs twice as much to charge.
There are some people on here who claim to regularly get over 5 m/kwh and if this is true they must be driving their MG so slowly that they are a danger to everyone around them, because I dont hammer mine in any way and its efficiency is always around 2.4m/kwh

That sounds very odd. Bear in mind that I have the same car as you have. I do not drive economically at all and I'm very fond of the heater in winter, and I agree I am getting about 2.4 miles/kwh just now because the temperature is still only 3-4ºC. Nevertheless I get around 3.5 miles/kwh in summer, approaching 4 if I'm doing a particularly economical drive (I mean, roads where I can't let the car rip).

Range as such doesn't worry me, because I don't often do more than 100 miles in a day, so I just charge overnight and I'm back on the road next day at 100%. I did think about getting the SE LR for its longer range and faster DC charging, but in the past year that would only have benifited me on six days, and overall it didn't seem worth it.

When you say range, do you mean the range the car is displaying for 100% charge, or the distance you're prepared to go before you decide a charge is necessary? Looking at what the car itself displays, I get 145-150 miles in winter (up to 160 or so if I've been doing longer, no-rush journeys) and 190-210 in summer. In terms of how far I feel I can realistically go before stopping to charge, then belting down the motorway in summer maybe 140-145 miles, more like 170 miles if I was proceeding at a more restrained pace. In winter I have done 115 miles, partly motorway, and as far as I remember I was on about 20% when I stopped to charge.

If you're starting a second leg from only 80-85% on a DC charger of course it's going to be less, but then if this is the sort of journey (that is, needing more than one rapid charging stop) you're doing regularly, then I don't think the SR is the right choice of car.

So I don't think your car sounds right in terms of the range you're actually getting, and in any case I don't think it was the right choice of model if you do trips of 300 miles or more on a regular basis.

Whatever is wrong with my car, it's put me off MG for good and it's put me off EVs in general because everything is a compromise with them and the only benefit used to be the price per mile but that ship sailed a while ago and its never coming back.

They say most EV batteries can only handle 1000 charging cycles, if you are charging yours daily then that gives you around 3 years before its goosed.
I hope you dont plan to own it.

"The MG4 has an estimated 1500 to 2000 battery charge cycles, which results in an exceptionally long battery life. Follow us on social or visit the MG Life blog for tips about how to increase the battery cycle life."

No one or very, very few will need to charge every day. Even every two days, which theoretically gives a minimum of 6 years and these will be very conservative numbers anyway. Someone charging once a week will get 20+ years.

Additionally, if the battery fails due to exceeding supported charging cycles within 7 years, it's covered under warranty to be replaced.

M101 said:

Whatever is wrong with my car, it's put me off MG for good and it's put me off EVs in general because everything is a compromise with them and the only benefit used to be the price per mile but that ship sailed a while ago and its never coming back.

They say most EV batteries can only handle 1000 charging cycles, if you are charging yours daily then that gives you around 3 years before its goosed.
I hope you dont plan to own it.

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From where I'm sitting, the only downside is the need to make charging stops on long journeys, and as I said I don't make many of these, and I'm getting to like the stops. Even though I don't have a variable tariff I'm spending WAY less on fuel than I did for my petrol car.

That's a load of rubbish about the batteries. For a start, there is a 7-year warranty on the battery. If it dips below 70% of its capacity as new before seven years are up - even if it's still absolutely hunky-dory apart from the reduced range - they'll give you a new one. Didn't you read the warranty terms?

Also, "charging cycles" doesn't mean the number of times you charge it. If you charge every day but only add 10% to the battery each time, then one charging cycle is ten days worth of charging. And as the previous poster said, 1000 cycles is way underestimating it. Even the 1500-2000 is I think referring to the NMC batteries, and the LFP in the SR is more than that.

But look. If you assume a modest 3 miles/kwh that's 150 miles for a full charge cycle. If you take the lowest estimate of charge cycles, 1500, then that's 225,000 miles battery life. If you do 10,000 miles a year, that's over 22 years. I've never been able to keep a car that long.

I do own my car, I paid cash, and I expect it to rust to bits before the battery fails.

M101 said:

Whatever is wrong with my car, it's put me off MG for good and it's put me off EVs in general because everything is a compromise with them and the only benefit used to be the price per mile but that ship sailed a while ago and its never coming back.

They say most EV batteries can only handle 1000 charging cycles, if you are charging yours daily then that gives you around 3 years before its goosed.
I hope you dont plan to own it.

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3 years? I don’t believe that unless you done exceptionally high mileage in that time

Of course you can get a bad battery just like you can get that bad petrol/diesel

There’s loads of videos on this but one I watched they stress tested 20 batteries, 1000 cycles of rapid charging them to 100%, drained then all the way down,

Now if you say those batteries averaged 200 miles, 1000 cycles = 200,000 miles

Now after they completed they found most had lost 5-9% capacity & I think it was 2 that lost 12%

And the battery management systems are getting better & better

Don’t get me wrong, I get your frustration, I’ve purchased products in the past that I’ve had a nightmare with & it’s enough to put you off for good so I get it but I’ve been a member of various forums, not just EVs but ICE cars & you can go on any of these forums, Audi, Ford, BMW, Tesla & you will always see some real horror stories

Again it doesn’t help you & it’s a royal pain in the backside but sadly it can happen with anything

I wish you luck moving forward

The engine on my Golf failed at only 30,000 miles. Do I go around telling people not to buy an ICE car because they'll have to buy a new engine after only 30,000 miles? No. It was a rare occurrence. The replacement was still going strong 105,000 miles later when the car was scrapped.

But I was actually very lucky. The car was still three months inside its 3-year warranty at the time, and the engine was replaced FoC. If it had lasted another four months I'd have been on the hook for a huge bill. And it would have to have been paid, because the car wasn't going anywhere without a functioning engine.

The MG4 on the other hand has a 7-year warranty. Now that says a lot. Manufacturers don't offer warranty periods where a significant number of units are going to fail within that period. As nobody expects an ICE to fail the minute it's out of its 3-year guarantee, nobody expects an EV to fail the minute it's out of its 7-year guarantee. The disparity in warranty periods says a lot on its own.

And consider. Batteries don't tend to stop working completely. They degrade. Less than 70% is held to be too much degradation. But suppose my battery degrades so that it only has 65% or even just 60% of capacity? The car will still be usable. I can go on driving it, even if I have to charge more frequently.

M101 said:

They say most EV batteries can only handle 1000 charging cycles, if you are charging yours daily then that gives you around 3 years before its goosed.

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Actually, if you really believe that, what on earth persuaded you to buy an EV in the first place?