Aggressive Turtle / Low Power mode after last dealership visit

[Yorkshire Hillbilly]

Does anyone else have any bother with Turtle / Low Power mode?

Since a dealership visit for a service and various updates my MG4 seems to be going into turtle / low power mode earlier than ever before.

For example, I could just about drive to my girlfriend's house and back on a full charge. I usually leave the M1 with about 12% battery and can then make it home at lower city speeds no problems.

However, since the updates the car goes into turtle mode anywhere between 7 and 17%. So now I'm getting within 5-10 miles of exiting the M1 and the car is refusing to give me full power and I'm limping along at 50mph on the up-hill sections.
*it's not season related as I used to be able to do the same journey last winter without the car going into Turtle / Low Power mode.

Just wondered if anyone else had noticed any changes recently?

 

[Rolfe]

My car is an SE so this may not be relevant to you, but I have never, ever seen the dreaded turtle, nor had the car's power significantly cut back - not even when I've said "yes" to the "do you want to enter energy-saving mode?" question which comes on about 10% charge.

I've been down to 4% charge and everything has been hunky-dory. So far as my car is concerned, turtles don't exist, and he seems to trust me to know where the charger is and to drive so we'll get there.

 

[siteguru]

I've never seen the turtle symbol, but I have had a degree of power limiting at low SoC - not enough to limit my speed though, just limiting acceleration.

 

[Rolfe]

I noticed the car was a bit reluctant to respond when I tried to gun it uphill at 12% charge on a cold evening, and that's about that.

 

[Yorkshire Hillbilly]

So far as my car is concerned, turtles don't exist, and he seems to trust me to know where the charger is and to drive so we'll get there.

Mine used to be this way too before the service and updates, now it starts crapping out at 15% and the turtle appears at about 7% even if I've still got 20+ miles range.

 

[Rolfe]

This needs a conversation with people who have Trophies and can interrogate which software versions you have.

 

[kenneth104]

I haven't encountered the turtle warning light, but the last battery will limit the power, which is not very obvious.It's warmer here

 

[TerryN]

I always think this is due to the BMS being out of "calibration" (the warning is triggered by the battery voltage not the GOM %). This could be an effect of not carrying out regular balancing & calibration (<10%-100% charge).

 

[Yorkshire Hillbilly]

This could be an effect of not carrying out regular balancing & calibration (<10%-100% charge).

Doubtful, each time I've done the journey I've charged to 100% and left the charger on for at least an hour after it's reached 100%. My driving habits haven't changed but the software has.

 

[nanomad]

This needs a conversation with people who have Trophies and can interrogate which software versions you have.

More than happy to run some queries and see what comes up, you can pm me If you want

 

[Rolfe]

Doubtful, each time I've done the journey I've charged to 100% and left the charger on for at least an hour after it's reached 100%. My driving habits haven't changed but the software has.

Have you been taking the car down under 10% then charging up to 100% in a single AC charge (followed by a balancing charge) every few months? The car needs to see the bottom of the well from time to time to get the GOM calibration accurate (or as accurage as it can be, anyway).

 

[Yorkshire Hillbilly]

Have you been taking the car down under 10% then charging up to 100% in a single AC charge (followed by a balancing charge) every few months? The car needs to see the bottom of the well from time to time to get the GOM calibration accurate (or as accurage as it can be, anyway).

Yup! I charge the car to 100% and let it sit connected for an hour then a day or two later I drive over to the girlfriends, stay a few days then back. I usually arrive home with around 7% however, since the updates it's not managing to get me home anymore.

 

[MGFour]

Yup! I charge the car to 100% and let it sit connected for an hour then a day or two later I drive over to the girlfriends, stay a few days then back. I usually arrive home with around 7% however, since the updates it's not managing to get me home anymore.

Think what others are suggesting is: have you charged it all the way from under 10% all the way to 100% plus leaving for balance in once session? As the BMS needs to recognise the state of batteries right through all the levels so it can accurately predict what is left. If your car had updates it may need this knowledge as previous data likely overwritten by updates. Another thing it could be some slight battery degradation did they provide you with battery state of health when you went into dealer.

 

[fnegroni]

This sounds like it could be either you haven’t left the battery at very low state of charge for long enough (which you indicate is unlikely to be the case) or really something has gone dullally with the software.
Just to rule the first one out, especially since a software update might have reset the GOM calibration or changed its values, I would suggest to bring it to 5% or less, let it rest for an hour or two, turn on the battery heating through the app if battery is below 10C, and after about half an hour, slow charge all the way to 100% and equalise.
It will at least rule out the possibility with the easiest fix.

Think what others are suggesting is: have you charged it all the way from under 10% all the way to 100% plus leaving for balance in once session? As the BMS needs to recognise the state of batteries right through all the levels so it can accurately predict what is left. If your car had updates it may need this knowledge as previous data likely overwritten by updates. Another thing it could be some slight battery degradation did they provide you with battery state of health when you went into dealer.

just realised I repeated the message above (my bad I must have missed it)
My caveat being: leave it at low state for a long time.
The Tesla maintenance app after a full equalisation also charges the car not in one swoop, but stops every 20% or so to let it rest at different states of charge after a full rebalance. Takes quite a long time but seems to have fixed many such issues.

 

[Ian Key]

@Yorkshire Hillbilly have you asked your dealer to reinstall the software update?

I had a problem where it appeared that they had updated some of the software with the SR version instead or the LR so reducing the indicated range. The cure was to book it back into the dealer who reinstalled the software.

 

[Rolfe]

Think what others are suggesting is: have you charged it all the way from under 10% all the way to 100% plus leaving for balance in once session? As the BMS needs to recognise the state of batteries right through all the levels so it can accurately predict what is left. If your car had updates it may need this knowledge as previous data likely overwritten by updates. Another thing it could be some slight battery degradation did they provide you with battery state of health when you went into dealer.

Yes. If people are on tariffs where they only have 6 hours (or less) off-peak electricity each night, they're often in the habit of charging up from a low SoC in more than one session. But every few months you need to arrange things so that you do it in a oner.

On Tuesday I happened to get home on 14%. I had to go out again in the evening to an event only three miles away. I did a small extra loop so that I was on 9% when I got there, so the car sat for a couple of hours below 10%. I drove home, got there on 8% just before 10 pm. I asked Octopus to add 100% by 6 am so there was no wiggle room to split the charge. In fact the car had got to 100% and balanced by 5.30 am, so I reckon that should do it for a bit.

 

[Yorkshire Hillbilly]

Update
After calling my dealership about the undertray thingy they advised that there's a bug in the Accumulated Total usage stats that's impacting the car's ability to judge its own range and how much battery is left.

They advised to reset it, charge to 100% and see what happens.

I reset it yesterday, drove to the office today and it's currently charging t 100% now.

The missus has since moved in with me so I'm not travelling back and forth to her house anymore however, she's dog sitting for a friend at the weekend so that'll be a good test. Will report back.

 

[siteguru]

That's not a bug ... all resetting the Acc Total does is reset the GOM (Guess-O-Meter) to near enough the factory WLTP figures; it does not mean the car's range suddenly increases.

 

[Yorkshire Hillbilly]

But if the car is basing the current remaining range on the historical GOM stats then it might think it's got less range and might go into turtle mode sooner. At least that's how I think the guy at the garage bullshit'ed me

 

[fnegroni]

Estimated range depends on estimate battery left and other factors, but estimate percentage left does not depend on the gom