Low Battery - Reduced Power

WAC 768 said:
After further investigation 60% power, reduction starts once the battery voltage goes under 400V and then ends up where with my foot pressed hard to the floor it barely gets over 20% power with 16% SOC still remaining. In today so let's see what MG says, but this is clearly unacceptable...
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Interested in what the dealer says
 
WAC 768 said:
After further investigation 60% power, reduction starts once the battery voltage goes under 400V and then ends up where with my foot pressed hard to the floor it barely gets over 20% power with 16% SOC still remaining. In today so let's see what MG says, but this is clearly unacceptable...
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well MG called me now after I complained and car is going in tomorrow as they say that is not normal .. so lets see
 
WAC 768 said:
After further investigation 60% power, reduction starts once the battery voltage goes under 400V and then ends up where with my foot pressed hard to the floor it barely gets over 20% power with 16% SOC still remaining. In today so let's see what MG says, but this is clearly unacceptable...
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That is unacceptable.
I'm having issues having done first 104 miles work round trip yesterday, want to collate another days data tomorrow, but it's not looking acceptable & may have to insist car is returned.
 
I don't think this issue is related to the January 2021 Update. I received the dodgy October 2020 Update but haven't yet received the January 'fix' yet, however I am experiencing the low power issue when I have a low state of charge. I could only reach 25mph going up a medium hill near my house the other night with my foot on the floor. I think I still had about 15/20 miles left on the GOM.
 
Dilp said:
I don't think this issue is related to the January 2021 Update. I received the dodgy October 2020 Update but haven't yet received the January 'fix' yet, however I am experiencing the low power issue when I have a low state of charge. I could only reach 25mph going up a medium hill near my house the other night with my foot on the floor. I think I still had about 15/20 miles left on the GOM.
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Sounds very similar but i'm also seeing reduced power from 40+ miles albeit 60%.The car at PDI in Dec 20 when i collected it, had all the latest updates applied and the problems only occured following the Jan BMS update...
 
FYI
I tested the reduced power today - regarding 400v.

(Mine is a new reg12/2020 car with latest updates)

I was at 398 volts whilst driving, in ECO mode.
I stopped, floored it, power gauge went up to 100%

My GOM was 77miles, SoC when I plugged in when got home (only couple mile journey) was 50%.
So wasn't at a particularly low SoC, but was below the 400v.
 
I get a heavy voltage drop when I floor it. I can have 75% battery cruising at 50mph with 410v, but if I floor it, the voltage can drop down to 390v and less, at that point the maximum power output starts dropping down in kind (the lower the voltage the lower the power).
I have had the latest fix for the BMS error and i am now at 434v after 2 weeks of use.
 
WAC 768 said:
Sounds very similar but i'm also seeing reduced power from 40+ miles albeit 60%.The car at PDI in Dec 20 when i collected it, had all the latest updates applied and the problems only occured following the Jan BMS update...
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same here
 
Just collected the car from the dealer and they have re-applied the BMS and something else (not sure what this was..). Interestly though i found out that they have had a couple of cars back with the same problem post update.... Hopefully it's sorted now but let's see.
 
WAC 768 said:
Just collected the car from the dealer and they have re-applied the BMS and something else (not sure what this was..). Interestly though i found out that they have had a couple of cars back with the same problem post update.... Hopefully it's sorted now but let's see.
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Let us know how you get on, fingers crossed for you.
 
WAC 768 said:
Just noticed when the low Battery warning comes on the cars now limited to 60% power, which i can't remember this happening pre the Jan BMS update but maybe it did, anyone else noticed this?
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Yes, the new update has messed up a lot of things. The range dropped 80 km, constant warnings "Slow Charge the Vehicle" etc...
 
Yes I noticed it for first time yesterday. I had just received the low battery warning (30 miles left) but as I was only 2 miles from home, not a problem. I put my foot down hard up a hill on fast A38 dual carriageway, and got very little response! Bit disturbing. I didn't look at power gauge at the time unfortunately. It was cold at -2c but I dont think that was the significant factor.
 
Sounds very familiar and it's certainly not temperature related. It would be worth running the battery down to around 15 miles then floor it whilst watching the power.
 
PaulinDerby said:
Yes I noticed it for first time yesterday. I had just received the low battery warning (30 miles left) but as I was only 2 miles from home, not a problem. I put my foot down hard up a hill on fast A38 dual carriageway, and got very little response! Bit disturbing. I didn't look at power gauge at the time unfortunately. It was cold at -2c but I dont think that was the significant factor.
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I completely get your experience: 2 miles from home, who cares if it says there's 30miles left on the range.
If I choose to use it, I want my full power available.

Personally (& I love the car) I don't think it's right, that I do not have the power available when there's still a fair bit left in the battery.
If I got to a big hill on a 60+mph road and couldn't drive at 60 due to the reduced power, then I do not think that classifies as usable range on the car. Hence the 163miles quoted is in fact 133 if it cuts the power at 30 to go.
 
JodyS21 said:
I completely get your experience: 2 miles from home, who cares if it says there's 30miles left on the range.
If I choose to use it, I want my full power available.

Personally (& I love the car) I don't think it's right, that I do not have the power available when there's still a fair bit left in the battery.
If I got to a big hill on a 60+mph road and couldn't drive at 60 due to the reduced power, then I do not think that classifies as usable range on the car. Hence the 163miles quoted is in fact 133 if it cuts the power at 30 to go.
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I’d get that checked out as i don’t think that’s right mine doesn’t do that apart from when I have my final warning to charge, and only notice the lack of power if I try and boot it...
 
Mine does the same. It is 3 months old and has not had any software upates yet. When I come to any sort of hill and I have around a third of the battery capacity left, power is reduced and the maxiumum speed I can get is 50 kmh which in a 70 kmh zone is not particularly enjoyable. The temperate is -19 C but this should not affect the car to that extent. The range is also severely reduced in this temperature. The GOM shows 191 km after a full over night charge, and after 10 minutes of heating the car before leaving and driving 23km to work it is down to aroung 100km. Less than 10km later power is reduced and as it is up hill for two thirds of the way home, it is a slow crawl and I have to turn off the heater. By them time I get home, it is down to around 50km range but this range is largely unusable as it is power limited by then. So at the moment in around -19 C, I have a usable range of about 30km. Off to see the dealer this week to see what they say.
 
DriverInNorway said:
Mine does the same. It is 3 months old and has not had any software upates yet. When I come to any sort of hill and I have around a third of the battery capacity left, power is reduced and the maxiumum speed I can get is 50 kmh which in a 70 kmh zone is not particularly enjoyable. The temperate is -19 C but this should not affect the car to that extent. The range is also severely reduced in this temperature. The GOM shows 191 km after a full over night charge, and after 10 minutes of heating the car before leaving and driving 23km to work it is down to aroung 100km. Less than 10km later power is reduced and as it is up hill for two thirds of the way home, it is a slow crawl and I have to turn off the heater. By them time I get home, it is down to around 50km range but this range is largely unusable as it is power limited by then. So at the moment in around -19 C, I have a usable range of about 30km. Off to see the dealer this week to see what they say.
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Again I cannot understand why, I’d get it checked out and confirmed.
 
DriverInNorway said:
Mine does the same. It is 3 months old and has not had any software upates yet. When I come to any sort of hill and I have around a third of the battery capacity left, power is reduced and the maxiumum speed I can get is 50 kmh which in a 70 kmh zone is not particularly enjoyable. The temperate is -19 C but this should not affect the car to that extent. The range is also severely reduced in this temperature. The GOM shows 191 km after a full over night charge, and after 10 minutes of heating the car before leaving and driving 23km to work it is down to aroung 100km. Less than 10km later power is reduced and as it is up hill for two thirds of the way home, it is a slow crawl and I have to turn off the heater. By them time I get home, it is down to around 50km range but this range is largely unusable as it is power limited by then. So at the moment in around -19 C, I have a usable range of about 30km. Off to see the dealer this week to see what they say.
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Mine's 2 months and at the request of my dealer had the new BMS update (Jan 21) to hopefully resolve the rapid charging speed problem (max 23kwh), which this has and have seen upto 37kwh @ 0c even when the batteries are cold, so more than happy with this. I have yet to test what happens when the battery gets low again (following deployment of update again 11/02) which i will do tomorrow and report back.

It does though seem and mentioned by you and JodyS21, we've purchased a car with a 165 mile range, knowing it would be slightly less in the real world and even worse in winter, but actually get around 60 miles of usable range with 100% power. This is clearly unacceptable and more importantly dangerous, should you pull out to overtake expecting 100% to find you've only got 25% available or come to a steep hill only to find the car cannot make it to the top...
 
I've emailed the dealer I brought the car from today, it's 14days on Tuesday since purchase.

I've mentioned
"I would expect the car to be able to do 163miles as per the WLTP test in a fully usable state, if part of this 163 mile range is with a severely restricted car that cannot maintain the necessary safe road speed, then it does not have the advertised usable 163mile WLTP range."

Will see what happens, hopefully there's a fault that can be fixed!
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