XPower feels slow and launch control not working

[olliewebb]

Sounds more like an issue with the individual car rather than a overall issue. Definately one for the dealer (if they cannot fix you are entitled to a full refund). This has been an issue with some cars and MG appear to have a fix, but you need to contact dealer and give them a chance to fix.

MG4 Power Limiting

I recently picked up a MG4. While driving the car on motorway, I've found a good few times now that the car is limiting the power for acceleration. Eg: If I'm trying to speed up to overtake, the car simply won't accelerate even when I have the accelerator fully pressed down. The battery is above...

www.mgevs.com

I don't think it's this issue - as the car will accelerate, but it will only give between 60-68% power. The front motor is turning on according to the display too.

I'm going to test my theory about the cold and try again.

So this is interesting... anyone had it where you are 'granny' charging the car to balance the battery and it's slowed down massively from 90 to 97% and take ages, only for it to jump from 97% to 100% in seconds?

Is my battery a dud? Also weird... it's still drawing power and the app still says it's charging... and the range is going up still. ?

 

[siteguru]

100% is a notional value ... it might reach it as a number (i.e. >99.5%) but not actually yet reach true 100%. And 0.5% of 61.7kWh (usable capacity) is 0.308kWh.

If the charge rate drops to low values (0.08kW or thereabouts) then you know it'll be doing a balance.

 

[fnegroni]

impossible to know without the appropriate tools, but that behaviour is consistent with an almighty unbalanced battery cell pack.

If that’s the case, I suggest you then use the battery pack all the way to <10%, better if close to 5 or even 3% and charge back to 100% in one single go on the slowest charge you can get.

This will allow the battery manager system to relearn the true low, half and full battery voltages.

 

[tsedge]

The XPower draws enormous amounts of power from the battery, so it is only going to be able to do this when the battery is warm and charged enough to cope with the draw.

It sounds as if with cold temperatures pre-heating the battery before setting off is essential and a high SoC - this isn't surprising, although it may point to the XPower's battery heating/cooling being somewhat inadequate if this is a common problem.

It could also be simply a bug, we've had a host of power-related bugs with the SR and LR versions in the past and an update might fix it,

I am wondering if MG skimped on the battery thermal management side for the XPower though.

 

[Kithmo]

Might this be a case for turning on automatic battery heating ?

 

[JonnyG]

Well I took my Xpower out today and had a play. It started at 65% charge and I had put a small fan heater underneath the car batteries set at 1000w for half an hour to heat everything up a bit. The car was then preheated inside for 10 minutes before coming out of my garage.

After 10 minutes driving I got on a dual carriageway and floored it. The power got to 99% very quickly and stayed there with no problems (Normal mode, OPD, LKA off.)

Coming back home I had 35% charge and tried again on same dual carriageway. The car went to 99% very quickly and again stayed there for around 5 seconds until my speed required reducing ?.

So my car would seem to be OK in short bursts and can provide nearly 100% power. I think I even saw 100% briefly.

Intelligent battery heating was turned on the whole time btw.

 

[salty]

Well I took my Xpower out today and had a play. It started at 65% charge and I had put a small fan heater underneath the car batteries set at 1000w for half an hour to heat everything up a bit. The car was then preheated inside for 10 minutes before coming out of my garage.

Shouldn't need to be putting a fan heater under the car to warm it up. Surely? ?

 

[JonnyG]

? Only when its sub zero out there. Keeps my connected garage and car a touch warmer and should help the cars range a bit IMHO. I think Bjorn Nyland does this too.

 

[olliewebb]

Might this be a case for turning on automatic battery heating ?

I had it on for the 20 miles trip to the 50 kW charger and it made no difference. All it did was sap range.

 

[Kithmo]

I had it on for the 20 miles trip to the 50 kW charger and it made no difference. All it did was sap range.

So it made no difference to the power available ?

 

[Mars6394]

Sounds more like an issue with the individual car rather than a overall issue. Definately one for the dealer (if they cannot fix you are entitled to a full refund). This has been an issue with some cars and MG appear to have a fix, but you need to contact dealer and give them a chance to fix.

MG4 Power Limiting

I recently picked up a MG4. While driving the car on motorway, I've found a good few times now that the car is limiting the power for acceleration. Eg: If I'm trying to speed up to overtake, the car simply won't accelerate even when I have the accelerator fully pressed down. The battery is above...

www.mgevs.com

I had this same issue in my SE SR as winter came last year it got worse.mine went in for a BMS update but it didn’t fix this issue.it was a know problem last year for a batch MG4.mine was u could put foot accelerator fully down and it wouldn’t accelerate hardly and pulling out was dangerous speed went up in increments of 1mph.i would defo get it booked in to be looked at.

 

[Mars6394]

I had this same issue in my SE SR as winter came last year it got worse.mine went in for a BMS update but it didn’t fix this issue.it was a know problem last year for a batch MG4.mine was u could put foot accelerator fully down and it wouldn’t accelerate hardly and pulling out was dangerous speed went up in increments of 1mph.i would defo get it booked in to be looked at.

Just to add to this the battery also lost charge fast went from around 85% to 30% with a 10mile trip my se sr was never the same. After I had this issue.i rejected it with other grounds also helping my case my car is now back up for sale cheapest in country I feel sorry for the person who is going to buy it

 

[Bricktop X PWR]

I had it on for the 20 miles trip to the 50 kW charger and it made no difference. All it did was sap range.

Not sure what's going on there @olliewebb ?

I hope you get to the bottom of it.

Took mine out this morning, minus 4.
(Car lives outside)
Pre heated before I left.
Got straight in at the 10 minute mark.
60% battery available.
Everything was on for the 1 mile it takes to get to the main road, seats, wheel, max demist, rear windows and mirrors.
I had a couple of opportunities to use full power on the main A40, and I had it.

No problems at all.

Well, that of course would be a lie!!

Bloody F.F.F. Would not close!
It was open all night as I was charging up my battery bank.
Tried a hair-dryer to warm up the mechanism.
Also a bit of W D Doody.
Wasn't having any of it.
Had to tape it shut in the end.

Used the search on here and was confident it would "sort itself out" when it warmed up a bit.
It did by the time I'd got to Carmarthen.

 

[olliewebb]

Not sure what's going on there @olliewebb ?

I hope you get to the bottom of it.

Took mine out this morning, minus 4.
(Car lives outside)
Pre heated before I left.
Got straight in at the 10 minute mark.
60% battery available.
Everything was on for the 1 mile it takes to get to the main road, seats, wheel, max demist, rear windows and mirrors.
I had a couple of opportunities to use full power on the main A40, and I had it.

No problems at all.

Well, that of course would be a lie!!

Bloody F.F.F. Would not close!
It was open all night as I was charging up my battery bank.
Tried a hair-dryer to warm up the mechanism.
Also a bit of W D Doody.
Wasn't having any of it.
Had to tape it shut in the end.

Used the search on here and was confident it would "sort itself out" when it warmed up a bit.
It did by the time I'd got to Carmarthen.

View attachment 21942

That sucks I’m sorry mate.

My findings today:

• Didn’t use battery heating
• Car was cold when I set off, but would give 100% power battery was >95%
• Drove around a bit got down to 80% battery and launch was working
• After getting <60% SoC I was only getting 96% power
• Launch under 60% won’t engage - tried Sport and Track Mode, just won’t work

So my conclusion is that it’s SoC rather than battery temperature in these weather conditions. I think there is more investigating to be done, what power level will it give me under 50%? Etc etc. But for now I know I won’t get full power unless I’m 60% or higher, in these weather conditions at least.

The good news is I managed to stop the brakes from squeaking by using the break-in method suggested by EBC, I’ve had EBC Yellowstuff and Redstuff pads before. Gave myself motion sickness in the process, nearly returned my breakfast as I opened the door at home.

Bad news is some in a heap of a ten year plus Qashqai has opened their door onto it and left a mark that goes beyond the clearcoat. 20 minutes with the dual action polisher and it’s still there, I daren’t hit in any more as I’m worried about going through the clearcoat. Of course they’d gone and not left a note, and I’ve not had my dashcam guy come out yet to install my NextBase camera. Grrrrr!! It’s three weeks old!

 

[olliewebb]

I had this same issue in my SE SR as winter came last year it got worse.mine went in for a BMS update but it didn’t fix this issue.it was a know problem last year for a batch MG4.mine was u could put foot accelerator fully down and it wouldn’t accelerate hardly and pulling out was dangerous speed went up in increments of 1mph.i would defo get it booked in to be looked at.

It’s not as slow as this, it feels more like a regular MG4 than a XPower.

 

[Bricktop X PWR]

That sucks I’m sorry mate.

My findings today:

• Didn’t use battery heating
• Car was cold when I set off, but would give 100% power battery was >95%
• Drove around a bit got down to 80% battery and launch was working
• After getting <60% SoC I was only getting 96% power
• Launch under 60% won’t engage - tried Sport and Track Mode, just won’t work

So my conclusion is that it’s SoC rather than battery temperature in these weather conditions. I think there is more investigating to be done, what power level will it give me under 50%? Etc etc. But for now I know I won’t get full power unless I’m 60% or higher, in these weather conditions at least.

The good news is I managed to stop the brakes from squeaking by using the break-in method reckoned by EBC, I’ve had EBC Yellowstuff and Redstuff pads before. Gave myself motion sickness in the process, nearly returned my breakfast as I opened the door at home.

Bad news is some in a heap of a ten year plus Qashqai has opened their door onto it and left a mark that goes beyond the clearcoat. 20 minutes with the dual action polisher and it’s still there, I daren’t hit in any more as I’m worried about going through the clearcoat. Of course they’d gone and not left a note, and I’ve not had my dashcam guy come out yet to install my NextBase camera. Grrrrr!! It’s three weeks old!

NIGHTMARE.

My biggest fear when out and about.
Some ignorant **** opening a door onto my car.
I park as far away from the sheep as is possible. (Always have done)
Even more careful now because of the matte paint.
Very well aware that I can't just polish out any defects.

Hope you get to the bottom of the power issue sooner, rather than later.

 

[olliewebb]

NIGHTMARE.

My biggest fear when out and about.
Some ignorant **** opening a door onto my car.
I park as far away from the sheep as is possible. (Always have done)
Even more careful now because of the matte paint.
Very well aware that I can't just polish out any defects.

Hope you get to the bottom of the power issue sooner, rather than later.

Yeah this is part of the reason I didn’t pick the green as much as I love it. Not being able to polish it and sort it out myself makes me nervous.

 

[olliewebb]

So it made no difference to the power available ?

Sadly not. Once I’d charged I got 100% back.

 

[fnegroni]

Now the battery pack is equalised, will you try if it would make a difference if you used intelligent battery heating under 60% SoC?

 

[olliewebb]

Now the battery pack is equalised, will you try if it would make a difference if you used intelligent battery heating under 60% SoC?

I’ve charged to 100% using 3kW twice over the last three weeks that I’ve had the car. Not sure it needed it all the same.

I’ll try tomorrow.