Turtle Mode (Cold Weather Warning)

[A-A-Ron]

This thread isn't depressing enough, maybe @Kamuelaflyer can come in and gloat a bit?

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[nuMach]

news article - tesla graveyards
guess we arent the only ones with charger network issues

https://www.msn.com/en-us/autos/new...raveyards-as-vehicles-wont-charge/ar-AA1n3h3I

 

[AKgrampy]

Something has to have changed. Sure it is colder for many but this is not the first Arctic blast for northern tier states and Canada and I do not recall any issues like this being reported last year. I rarely if ever get below 30% so I can’t say myself.

 

[Kamuelaflyer]

This thread isn't depressing enough, maybe @Kamuelaflyer can come in and gloat a bit?

It’s cold here at the moment too. 48 F coming up on 6 am, probably a chilly 70F down at the beaches right ow.

I have a great deal of sympathy for those with cold soaked vehicles. I had to do that with airplanes for most of my career. Not fun.

 

[GarageWarrior2023]

I doubt it. At least not w/ the Bolt.

I can speak to this, I had a 2022 BOLT EUV before my 23 Mach-E and the BOLT was perfect, no heating issues and no power limiting or speed limiting issues. my experience with the bolt was part of what got me 100% onboard with EV use in the winter. Now I'm left thoroughly disappointed with the Mach-E and winter.....

 

[GarageWarrior2023]

I've made a formal complaint with my dealership about this programmed behavior issue for both my Mach-E vin's.

Who else is going to be reporting this issue? the more of us make official reports/complaints the better chance that something actually gets addressed.

 

[medriver]

I was wondering how any BEV handles this situation in fact I thought about this very thing.

Leave the car out in -40 and it's going to have to use a lot of power to not have the battery suicide itself.

Drive at 80MPH...imagine the convective heat transfer..lol.

My curiosity is peaked, is this an underspeced heater, limiting heat loss, etc, curiosity abound.

Hopefully somebody hears from Ford, cant imagine the behavior going away, hopefully it can be tweaked.

 

[jgcom]

I think it is just the coldest winter on record since the Mach E has been released. We're seeing a much larger sample size of extreme cold in these vehicles than we ever have before.

indeed. When the outdoor charger plugs in south Louisiana are coated in ice, you know the cold season is unusual.

 

[dtbaker61]

This sort of thing makes me wonder what in the heck the engineers are testing when they do their "cold weather testing" on a frozen arctic track?

I am pretty well versed in QA scenarios, and this seems like an immediately obvious test case. Or did the folks at Ford only "cold weather test", after preconditioning, and coming off of a 90% charge??

This seems pretty crazy, particularly and totally unreasonable from a consumer safety perspective, let alone what a consumer expects out of ordinary vehicle behavior and performance. To be clear by "performance" I mean being able to safely maintain highway speeds at a minimum, while you are not riding on empty. Anything less, and it should not have been certified road worthy!

That said, all of this sounds software limited to me, as ive never heard of anything like this with any other EV, and it's likely the result of Fords incredibly conservative (to a fault) approach to engineering, and this needs to be fixed asap via a priority update (given present conditions in North America), even if it is hard on the battery!

testing of DRIVING with a cold battery is one thing.... CHARGING a cold battery is completely different.

The 'most common' scenario *probably* is L2 charging at home inside garages overnight. Doesn't really matter how cold it gets since being plugged in will warm battery, charge, and then keep battery warm until driven for the day. no problems for *most* daily use.

However, problem scenerio is when the EV sits outside for x hours and core temp is <0F.... which can be driven, but not charged. There is some (much lower) temp at which the car cannot be driven at all until some battery capacity is used to warm batteries. I don't know the exact temp, or what the software algorithm is to inform drive that you cannot drive until batteries have been brought up to xx temp.

If temps are really cold, like -xx degress, and cabin heat is requested, batteries may not ever get warm enough to DCFC charge if remaining capacity is insufficient to heat them up.... hence, Ford created turtle mode to preserve capacity for pre-conditioning prior to DCFC.

what would maybe be more user friendly would be to communicate via handshake at a DCFC charger that batteries are cold, so start charge via CCS L2 connectors and divert to precondition batteries up to temp, and THEN charge via DCFC. This would obviate the need for turtle mode and allow use of full battery capacity to get to the charger.

...but apparently that is not what Ford Engineers did

 

[dtbaker61]

I was wondering how any BEV handles this situation in fact I thought about this very thing.

Leave the car out in -40 and it's going to have to use a lot of power to not have the battery suicide itself.

Drive at 80MPH...imagine the convective heat transfer..lol.

My curiosity is peaked, is this an underspeced heater, limiting heat loss, etc, curiosity abound.

Hopefully somebody hears from Ford, cant imagine the behavior going away, hopefully it can be tweaked.

software can always be tweaked, its a matter of telling it to do the right thing.

and I can imagine a 'cold weather battery warmer' tray (optional) could be bolted up underneath, with a little insulation and small amount of heat pulled from batteries to simple 'warmers'.

I could fabricate something in a day with a sheet of 1/8" abs, mylar space blanket, and a 12v blanket if I lived in an area, or was planning a roadtrip thru an area where temps were -xx degrees. Bolt that sucker up right to the battery rails, and keep battery temp up.

 

[music_cities]

I shared this in another thread but thought I would share here as well.


Finding this thread just now after having a pretty scary experience yesterday.

I went to ski at a resort an hour from my house. It was 1 degree F out with a windchill of -21. I charged the car to 100% and warmed it up before leaving. Arrived at the resort at 65% (had a seasucker ski rack mounted as well). Skied for 4 hours and then went home. While taking off my gear I ran the heat at full blast (it was still -21F windchill). The cabin warmed up enough during this time and off I went. The drive is mostly highway and I held 85MPH comfortably and safely. With the heat set to 85 Auto Speed 2. Around 45 minutes in I began to notice the heat was not as warm but really didn’t think much of it. Then suddenly I see a yellow turtle on my dash. As this happens the speed of the car begins to reduce (even though cruise is enabled and set to 85). Eventually it settles at 70MPH. Im only a few miles from my exit so I opt to just keep going vs pull over etc. Suddenly the turtle turns red and my speed drops again. The car is now struggling to hold 55 (in a 70 ?). Luckily I am only half a mile from my exit. Upon getting off and slowing down (thus engaging the regen) the turtle is gone. I safely drive the car home. It’s worth noting this all happened when I had 22% down to 18%. The battery was not even in single digits.

does anyone have advice on how to prevent this in the future? I plan to follow the advice of this thread however I don’t have a charger at the ski resort and I did drive home with the heat on auto 2. Perhaps next week I will turn the temperature down and try driving 75 instead of 85?

had the car 2 years now and have never had an issue like this, however it typically does not hit -20 windchill where I live. Usually a week of 0 or -5 at the lowest.

If I'm reading it right your *cabin* interior temperature was set at 85F? !!!??? Please turn it down and let us know if it helps. I'll wear my ski clothes for the first 30 minutes after skiing, but if I'm driving further than that I change to a spare toque and coat, or a very big nice wool sweater. (I have two amazing sweaters, one is from Ireland and the other my kids got my for Christmas one year.) Once the chill is off we're usually cruising at around 18.5C (65F) maybe up to 19.5 and we're warm and happy.

I also slow down a little e.g. to the speed limit when it's very cold, so maybe try 75 which I guess is still 5mph over the speed limit, right? 85mph is pretty fast, most highways are not designed to be safe at that speed (transportation engineer here.).

Would like to know if this helps.

 

[aberberich]

If I'm reading it right your *cabin* interior temperature was set at 85F? !!!??? Please turn it down and let us know if it helps. I'll wear my ski clothes for the first 30 minutes after skiing, but if I'm driving further than that I change to a spare toque and coat, or a very big nice wool sweater. (I have two amazing sweaters, one is from Ireland and the other my kids got my for Christmas one year.) Once the chill is off we're usually cruising at around 18.5C (65F) maybe up to 19.5 and we're warm and happy.

I also slow down a little e.g. to the speed limit when it's very cold, so maybe try 75 which I guess is still 5mph over the speed limit, right? 85mph is pretty fast, most highways are not designed to be safe at that speed (transportation engineer here.).

Would like to know if this helps.

Yeah I think that is my plan when i re-do this same drive this coming sunday (in what looks to be similar weather as well!). I'll slow it down and turn the heat down as well and report back!

 

[ArthurDOB]

This is very bad. This is a safety issue. I wish I knew about this turtle mode before buying a Mach E.

Dude, you live in Texas. You'll likely never have to worry about this!

 

[jgcom]

Our resistive heaters are 5 kW. There is also some heating due to losses in the battery and motors. If the heat loss exceeds that, no software can change the outcome, which is that eventually the battery will cool and the traction power will need to be throttled to avoid damage. I suppose what we would like is earlier warning/notice of this inevitability?

Driving harder/faster makes things worse, unlike with a thermodynamically inefficient ICE.

Teslas, AFAIK, use two different methods to produce heat, a heat pump (which isn't terribly good at some of the extreme temperatures you folks have been mentioning) and via a special mode of the motor drive electronics to use (I think) a deliberate phase offset between the windings to make it less efficient, thereby generating a few kW of heat per motor.

This has all been covered in the forum before, usually at this time of year.

 

[BB023]

So driving to work - parking the car outside for 8 hours at -5F. Should I be preconditioning the car for departure at 5 pm even though it’s not on a charger? Or just remote start the car and drive away?

I have 70% battery. Trying to understand the best approach. My drive will be 25 min.

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