Reduced power mode at 23%

[Jomarkh]

You need to just leave the car connected it will do it after it reaches 100%.
If it is done regularly then the time itvtakes reduces unless you dona lot of rapid DC charging.

 

[Biccys]

It happens automatically (if needed) once the battery is fully charged if it's still plugged in and powered.
I've not done a balancing charge in the 1K miles I've covered so far because I've only had the battery at 100% once in that time. The handbook says that the car will warn you if it thinks it's required:

If an equalisation charge has not been carried out for some
time the message centre in the instrument pack will display
'Please Charge for BMS Balance'.

That's good to know. I was wondering if my almost 50 year old brain would remember to do the balancing on a monthly basis but if the electronic brain of the car prompts me to do it I'm more relaxed about it now!

 

[Jomarkh]

If you forget to turn it off it will keep charging and balance anyway

 

[Gomev]

That's good to know. I was wondering if my almost 50 year old brain would remember to do the balancing on a monthly basis but if the electronic brain of the car prompts me to do it I'm more relaxed about it now!

I wouldn't wait until the car warns you. If it gets that much imbalanced then it's bad, will take hours and hours to balance and will require several balance charges to finish the job.
It really isn't difficult to occasionally charge to 100% when you can and let it balance. (you don't have to do it religiously every month).
If you need to use the car then unplug even if it is charging or balancing, it won't do any harm but at least part of the job will have been done.
Remember when it is out of balance you lose range, the more out of balance the more the range loss.

 

[Biccys]

I wouldn't wait until the car warns you. If it gets that much imbalanced then it's bad, will take hours and hours to balance and will require several balance charges to finish the job.
It really isn't difficult to occasionally charge to 100% when you can and let it balance. (you don't have to do it religiously every month).
If you need to use the car then unplug even if it is charging or balancing, it won't do any harm but at least part of the job will have been done.
Remember when it is out of balance you lose range, the more out of balance the more the range loss.

Yeah I will be charging at work at our 7kW charger and probably very rarely at home so I guess it'll be going to whatever it gets to when I go to work! (I know, I'm a lucky git!) I will probably use the granny to do the balancing every once in a while at home.

 

[gaxx21]

Hello my MG5 broke down completely it was at around 14% I knew it needed charging and as I was 4 miles from home on a steep hill I had had the warning to connect to a charger. It slowed drastically and came to a stop with a message on the dash that the HV battery had shut down. I tried to shut down and re-start but it made no difference the car would not move at all. I had to phone 999 and the police came and shut off the carriageway until a recovery vehicle could pick me up and take me to the dealer. The dealer phoned me and said it was because of the low charge the car had gone into "Turtle" mode they told me that I should never let the battery go below 40%!!! and they said that was from the manufacturer.

 

[BruceT]

"Turtle" mode they told me that I should never let the battery go below 40%!!! and they said that was from the manufacturer.

40% that's ridiculous. Straight from the manufacturer my arse! Was that your local dealer?

 

[lebelinconnu]

I agree, completely outrageous. I would have thought there must be some sort of fault with the car that they are trying to blame on you.

 

[Ozzie1989]

I get that it should limit the power a bit and warn you, but to stop like that is downright dangerous.

At the bare minimum it should give you a 1 minute countdown (preferably 2) so that you can get the vehicle off the road/onto hard shoulder.

 

[Petriix]

Hello my MG5 broke down completely it was at around 14% I knew it needed charging and as I was 4 miles from home on a steep hill I had had the warning to connect to a charger. It slowed drastically and came to a stop with a message on the dash that the HV battery had shut down. I tried to shut down and re-start but it made no difference the car would not move at all. I had to phone 999 and the police came and shut off the carriageway until a recovery vehicle could pick me up and take me to the dealer. The dealer phoned me and said it was because of the low charge the car had gone into "Turtle" mode they told me that I should never let the battery go below 40%!!! and they said that was from the manufacturer.

The software is definitely patchy. Obviously you'd prefer it to prevent damaging the battery, but it should do this by gently limiting power, not shutting off completely.

We all need to be aware not to attempt to go above halfway on the power dial when it's cold and the battery is low. That means being particularly gentle on the power on the way up hill.

It's far from ideal.

 

[Ozzie1989]

I had to phone 999 and the police came and shut off the carriageway until a recovery vehicle could pick me up and take me to the dealer.

Out of interest, did you happen to know how the recovery agent got it into N to move it?

Just thinking that in some cases if this were to happen to us, being able to put the vehicle in N and release the handbrake would be enough to get it off the road.

Also, does anyone know if it's possible to tow the MG5 in N with all 4 wheels on the ground?

 

[bobs2293]

Are we all honestly saying the car shuts down at 14%?

 

[AnonymouseDriva]

Also, does anyone know if it's possible to tow the MG5 in N with all 4 wheels on the ground?

Not according to the manual...

 

[Petriix]

Are we all honestly saying the car shuts down at 14%?

No, but the car can trigger an error state at 14% if it's cold and you try to draw more power than the BMS will allow.

So, as there's clearly some poor programming in the software, be cautious when it's cold and the battery is low and maybe don't accelerate up hill.

 

[MG5]

Would this also be a case of needing balance charge? If 14% shows on screen but in reality the battery has less charge?

 

[Petriix]

Would this also be a case of needing balance charge? If 14% shows on screen but in reality the battery has less charge?

I imagine that an imbalanced battery would be more prone to suffering such issues and it could be a warning sign of having one or more weak cells.

The point being that, while the overall energy stored in the battery might well reflect 14% of the total usable capacity, a single cell sitting at a lower voltage would prevent any further energy being released from its entire module once it hits whatever the low threshold is.

Demanding high power from a battery will suddenly (temporarily) drop the voltage. Heavy acceleration up a hill in the cold when the voltage is already low risks triggering a low voltage threshold. The MG software seems to hit an emergency shutoff trigger rather than simply reducing the available power.

 

[gaxx21]

I have had the car go into reduced power before which wasn`t a problem I got it home gently I think it ended up on 9% but whilst it was slower it still got me home to charge, this was different I had the message that I should charge ASAP and the reduced power warning came up. The weather was cold 0 degrees and I was trying to get up a steep hill about 4 miles from home was overtaking an old van that was struggling to do 15mph when I suddenly lost power had to pull in behind the van where my car stopped.
On the dash it came up something like "HV battery fault" I tried shutting down and re starting but no change. I got out of the car and tried to ring the RAC I know I had seen a emergency button but I thought it was on the screen I, was getting concerned with other traffic not seeing me as the sun was low on the horizon and they were driving into it.
The RAC can`t be contacted by phone in the first instance and the website advises if on a major road to contact the police so I did that I had walked back down the hill to put my Warning Triangle out, just before the police arrived a truck ran over it!!
The initial response from the RAC was quite good within 1/2 hour the patrol rang and once advised what the symptoms' were said he would have to arrange a flatbed as he wouldn't be able to work on it where it was. I subsequently heard nothing back from the RAC the police then contacted them after about a hour and were told it would be another 2 hours before they got to me!!
The police had to clear the road so arranged a flatbed to take the car to the dealer at my expense (hope I can claim this back from somebody) I managed to get the car in neutral as the dashboard now came to life (still said HV fault) and I sat in and took the handbrake of and steered a little as he winched it onto the flatbed.
Not best pleased with the dealer nobody was bothered when the car arrived the recovery driver was just told to put it anywhere I had no curtesy car and had to make my own way home by train and bus one of the sales guys did give me a lift to the station.
The dealer contacted me later that day and said the car was ready and they had updated the software for the recall the told me that it was because I had let the battery get too low they hadn`t charged it so I had to collect it the following day. I have a video message on my phone from the dealer that says about not letting the car go below 40% if I can work it out I will try to link it here.

Ps I love the car don`t think I could go back to petrol or diesel again just a bit of a learning process.

 

[Alb]

I'd be very interested in seeing that video message.

 

[SDP79]

I have had the car go into reduced power before which wasn`t a problem I got it home gently I think it ended up on 9% but whilst it was slower it still got me home to charge, this was different I had the message that I should charge ASAP and the reduced power warning came up. The weather was cold 0 degrees and I was trying to get up a steep hill about 4 miles from home was overtaking an old van that was struggling to do 15mph when I suddenly lost power had to pull in behind the van where my car stopped.
On the dash it came up something like "HV battery fault" I tried shutting down and re starting but no change. I got out of the car and tried to ring the RAC I know I had seen a emergency button but I thought it was on the screen I, was getting concerned with other traffic not seeing me as the sun was low on the horizon and they were driving into it.
The RAC can`t be contacted by phone in the first instance and the website advises if on a major road to contact the police so I did that I had walked back down the hill to put my Warning Triangle out, just before the police arrived a truck ran over it!!
The initial response from the RAC was quite good within 1/2 hour the patrol rang and once advised what the symptoms' were said he would have to arrange a flatbed as he wouldn't be able to work on it where it was. I subsequently heard nothing back from the RAC the police then contacted them after about a hour and were told it would be another 2 hours before they got to me!!
The police had to clear the road so arranged a flatbed to take the car to the dealer at my expense (hope I can claim this back from somebody) I managed to get the car in neutral as the dashboard now came to life (still said HV fault) and I sat in and took the handbrake of and steered a little as he winched it onto the flatbed.
Not best pleased with the dealer nobody was bothered when the car arrived the recovery driver was just told to put it anywhere I had no curtesy car and had to make my own way home by train and bus one of the sales guys did give me a lift to the station.
The dealer contacted me later that day and said the car was ready and they had updated the software for the recall the told me that it was because I had let the battery get too low they hadn`t charged it so I had to collect it the following day. I have a video message on my phone from the dealer that says about not letting the car go below 40% if I can work it out I will try to link it here.

Ps I love the car don`t think I could go back to petrol or diesel again just a bit of a learning process.

I have to say that this sounds outrageous. Glad to hear that you are OK but service from all concerned leaves a lot to be desired. I have been reading this thread and am quite alarmed that the car decides to go to low power when if still has power left. Surely this is up to the driver? Like an ICE car does not got in to lower power or limp mode when the fuel light comes on! As for the comment from the dealer that you should not let battery go down below 40% and MG advise not charge to over 80%. Claimed range is 250 miles but according to this theory you can only use 40% so the range is effectively 100 miles. Quite clearly this rationale is total tosh!
I always charge to 100% over night with Octopus Go. I asked on this site if I could limit this to 80% and got told no and asked why I did not know this!
So where are we now? My experience with EV's - let me qualify this. - this MG5LR, is my second and the first a Nissan Leaf 40kw. Only once have I gone down to less than 10% battery charge - this was in the Leaf and there was no limp or lower power mode employed. I got home with my own judgement and great care. My wife has just returned home in the MG and the level was down to 39% - no low power mode employed.
I can only see the need for a low power mode if there is a fault with any of the car s systems - this would be very rare we must assume. Doing this on an ad hoc basis when there is low battery charge is, as described in the quote dangerous.
I am going to continue charging as I currently do. I definitely do not charge when there is 90% or more in the battery.
But I am worried about this sudden switch to lower power mode - Anyone brought this up with MG?

 

[Ozzie1989]

As has been said there are others who've got to 1% without it cutting out, could well be a fault with the vehicle and what sounds like a rubbish dealer who is happy to basically call their customer stupid for using the vehicle to it's full capacity.

This will always be the issue with franchised dealerships, if it won't clearly make them money they won't invest in it, even if it's to keep the customer happy for repeat visits or to learn a thing or two.

I would suggest that a number of us ask MG to provide a future software update at service time that gives a countdown (at least 60 seconds) before it goes into 'slow' mode and the same for cut off. Gives you time to get to relative safety and make decisions from there.