Sudden Turtle Mode in Very Cold Weather

[rodenti]

The 12V battery is being charged when the traction battery is actually charging, but not when the car is plugged in after traction battery charging is complete (or if waiting for charge timer to start charging).

Thanks! That's good to know.

Drove my Leaf again tonight in even colder weather after a full charge and all went well... no turtle mode.

[SageBrush]

Drove my Leaf again tonight in even colder weather after a full charge and all went well... no turtle mode.

The pack temperature matters, not the temperature outside

[DunanyDon]

Yesterday morning it was -25 °C and I drove my daughter to work. The car had been plugged in overnight with the delayed charge on. The SOC was 94%. After a few hundred yards without any rapid acceleration, the turtle icon came on and was still on when I arrived at work (about 20 km). I turned the car off and on and the turtle icon was off. While the icon was on, the behaviour of the car was normal as far as I could tell. I guess only Nissan`s software engineers know why this would happen.

[binks]

This past two weeks with the super cold have been not great for this car

[rodenti]

This past two weeks with the super cold have been not great for this car

Same here. Turtle mode again this morning at -25°C, but still drove as normal. Driving home in the afternoon the turtle was gone. Doesn't seem to affect the driveability of the vehicle, but definitely bothers me when the turtle appears.

Maybe I'll bring it into the dealership for its yearly service a little early.

[binks]

This past two weeks with the super cold have been not great for this car

Same here. Turtle mode again this morning at -25°C, but still drove as normal. Driving home in the afternoon the turtle was gone. Doesn't seem to affect the driveability of the vehicle, but definitely bothers me when the turtle appears.

Maybe I'll bring it into the dealership for its yearly service a little early.

It does for me. We've been in the situation where using the highway is not an option.

[Stanton]

The 12V battery is being charged when the traction battery is actually charging, but not when the car is plugged in after traction battery charging is complete (or if waiting for charge timer to start charging).

^^^THIS
Which is why it's good to have a nice, long charge on L1/L2 (also charges the 12v) and then unplug when complete (keeps from draining the 12v)!

[gcrouse]

I have had the turtle mode come on here recently at around 68 or so SoC and 6 degrees after being unplugged. It had started happening last year. I consider it a phantom turtle mode since the car drives normally (don't do much highway driving). I was more concerned last year and took it in early for service and Nissan didn't find anything.

Generally speaking it seems to go away once the battery temp bars get out of the lower two blue bar area.

My hunch is that the cold weather affects the BMS readings of the cells and may be indicative of weaker cells that are going to go bad earlier than others.

Generally speaking to avoid it I think best practice is probably to consider plugging it at whatever temp is necessary to help keep battery warm and utilizing climate control timer to precondition car before departure

[alozzy]

It would be helpful to the community if someone uses LeafSpy, while the car is in turtle mode, to see if there's a large cell imbalance.

[LeftieBiker]

It would be helpful to the community if someone uses LeafSpy, while the car is in turtle mode, to see if there's a large cell imbalance.

There pretty much has to be, unless ALL of the cells are low. Cell voltage is what the BMS uses to assess the battery while driving.