power restricted

[Jaygee]

I was driving home from work yesterday, 6 miles into the trip, 2 bars of battery remaining.
I attempted to overtake a car which decided to speed up just as I was overtaking it. Slowing down was not an option as another car had taken my place.
Anyway I decide to floor the accelerator and to my utter surprise the power meter did not go past 80%. Thinking I had not pushed it down all the way I attempted to do the same on a clear stretch of road, once again only unto 80% and would not go beyond no matter what.
I have never had the need to use more than 50-60% until yesterday.
Is there a reason for this, could it be the low SOC ( it was 33% when I plugged it in), or was it that the drive and power train had not warmed up?
I know it is a trivial thing but I just can't let that go and it is keeping me awake..

 

[Srp111]

I think it's due to the low charge, it likes to keep the power down when you are low on charge, try it again when your gully topped up and you'll see the difference

 

[Cocijo]

Depending on how balanced your battery cells are you will get reduced power at certain levels of charge. This is because the bms will only allow power based on the lowest voltage cells in order to protect them. Some cars will still give a burst of 100% at lower charge levels as long as the pack is nicely balanced.

 

[Kithmo]

Was the road wet ?
Traction control limits power as well.

 

[JodyS21]

I was thinking about this the other day.
In regard to the voltage shift now applied to max and min charge.
By altering our usage capacity to a (5v) lower range, I think it will now mean being power limited earlier than it would have been previously at the slightly higher voltage.
Conversely I know it means regen can occur straightaway, but I think it maybe at the expense of low charge power available.

Thoughts?!?

 

[Jaygee]

Thanks for replying guys. The road wasn’t wet as far I could discern. There was no indication of the traction control kicking in.
My BMS appears to be the newer one as I have 449v fully charged. Appears that it is balanced as well if it is reading that.

 

[Jaygee]

I was thinking about this the other day.
In regard to the voltage shift now applied to max and min charge.
By altering our usage capacity to a (5v) lower range, I think it will now mean being power limited earlier than it would have been previously at the slightly higher voltage.
Conversely I know it means regen can occur straightaway, but I think it maybe at the expense of low charge power available.

Thoughts?!?

Certainly appears to be the case. I get pretty decent regen from fully charged.

 

[WAC 768]

Certainly appears to be the case. I get pretty decent regen from fully charged.

Have similar problems even with the new BMS and fully balanced battery. Worst I’ve seen is 30% power up a small incline (2%) and car would not go above 25mph with 16% SOC remaining. Now the weathers warmed up with similar SOC 40% is achievable. This in my mind is clearly dangerous and MG are looking into this.
I don’t and won’t accept any power reduction without first warning you.

 

[AbuG]

I ran my battery flat yesterday intentionally to see the effects and voltage. It restricts power during the last bar to 80% then 60% and later to 40% . I can't remember the exact milages and percentages.

Some users on the Jan 2021 (AO1) update had it at higher battery levels (just under 45-50%) the Feb (EU1) update should fix that.

 

[Jaygee]

Have similar problems even with the new BMS and fully balanced battery. Worst I’ve seen is 30% power up a small incline (2%) and car would not go above 25mph with 16% SOC remaining. Now the weathers warmed up with similar SOC 40% is achievable. This in my mind is clearly dangerous and MG are looking into this.
I don’t and won’t accept any power reduction without first warning you.

I agree, this is dangerous, I would rather there be a SOC or range penalty but the full 100% power should be available at all times. There are quite a few ICE cars that allow an overboost for a short period to get you out of trouble, yes it messes up the engine but it is there if you need it.
The boost section of the gauge should read "if I feel like it"
Saying I am disappointed is an understatement. I wonder if this is true of other BEVs.

 

[WAC 768]

I ran my battery flat yesterday intentionally to see the effects and voltage. It restricts power during the last bar to 80% then 60% and later to 40% . I can't remember the exact milages and percentages.

Some users on the Jan 2021 (AO1) update had it at higher battery levels (just under 45-50%) the Feb (EU1) update should fix that.

I would tend to agree with your findings, however this can vary depending on temperature and incline but to restrict power without warning from 25% SOC is not what anyone was expecting when they bought the car and I’m sure the dealers don’t mention this before taking your cash

 

[AbuG]

I would tend to agree with your findings, however this can vary depending on temperature and incline but to restrict power without warning from 25% SOC is not what anyone was expecting when they bought the car and I’m sure the dealers don’t mention this before taking your cash

I can't remenber for certain but I think the restriction starts when the last bar starts to flash. Which I think is around 10% remaining of the usable battery.
Then to 60% around 7.5% (flashes up warning then not to drive aggressively or something similar)
Then 40% power, I'm guessing was close to 5% remaining of usable battery.

 

[WAC 768]

I can't remenber for certain but I think the restriction starts when the last bar starts to flash. Which I think is around 10% remaining of the usable battery.
Then to 60% around 7.5% (flashes up warning then not to drive aggressively or something similar)
Then 40% power, I'm guessing was close to 5% remaining of usable battery.

This is not my experience and mine starts from 25% SOC with 40% power coming around 16% SOC even with the EU1 BMS

 

[AbuG]

I am on the factory installed June BMS... That maybe the difference.


Edit
I would personally resist any updates at present

 

[AbuG]

It's not surprising the power restriction is happening at a higher level of remaining battery, since they have adjusted the buffers to lower levels in the 2021 updates.
This also has desirable side-effects of being able to rapid charge at faster speeds and at higher levels of SoC and for longer. Also the regeneration at 100% dash charge level.

 

[Mike]

I’m sure the dealers don’t mention this before taking your cash

I bet they don’t know about this.

 

[Dave53]

I was driving home from work yesterday, 6 miles into the trip, 2 bars of battery remaining.
I attempted to overtake a car which decided to speed up just as I was overtaking it. Slowing down was not an option as another car had taken my place.
Anyway I decide to floor the accelerator and to my utter surprise the power meter did not go past 80%. Thinking I had not pushed it down all the way I attempted to do the same on a clear stretch of road, once again only unto 80% and would not go beyond no matter what.
I have never needed to use more than 50-60% until yesterday.
Is there a reason for this, could it be the low SOC ( it was 33% when I plugged it in), or was it that the drive and power train had not warmed up?
I know it is a trivial thing but I just can't let that go and it is keeping me awake.

Were you on Eco, Normal or sport? that can make a big difference to the acceleration

 

[AbuG]

Were you on Eco, Normal or sport? that can make a big difference to the acceleration

They don't affect the maximum power when fully floored,
they affect the power to accelerator pedal depression curve.

 

[Dave53]

They don't affect the maximum power when fully floored,
they affect the power to accelerator pedal depression curve.

? should have read it more carefully did not pick up that you floored the pedal that should override everything, I would also expect to have access to full power to the drive unit unless I had been warned not to by the car, that is very dangerous, with lockdown not many people are getting the chance to experience various quirks of EV's especially the MG.

 

[Jaygee]

Were you on Eco, Normal or sport? that can make a big difference to the acceleration

I was in normal mode. I don’t like the eco mode and find the sport too aggressive.