Turtle Mode (Cold Weather Warning)

[redgrandam]

I made another thread about my LFP model in the cold. It’s on topic for this line of discussion incase anyone is interested:

https://www.macheforum.com/site/threads/observations-from-an-lfp-mach-e-owner.42283/

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[Mach-Lee]

Edited the original post to include a mitigation strategy for turtle mode. If you encounter turtle mode, pull over and turn off the HVAC for 15 minutes (or charge the battery). This allows the battery to warm up and eliminates the power limits.

The latest powertrain software incorporates automatic battery heating to +3ºC in cold conditions, but it requires the absence of an HVAC load. Turning off HVAC enables the full heater power to be utilized on the battery. Although you may notice a slight battery drain of about 3% during the 15-minute warm-up period, your range won't decrease or may even increase because the battery is being warmed, unlocking additional capacity. In theory, stopping to warm up the battery should enable you to reach 0% charge without triggering turtle mode. However, in practice, if the battery is extremely cold, you might need to stop for another warm-up if you encounter turtle mode again.

Turtle mode will activate when the battery temperature drops to 3ºC or less and the battery level is low (exact threshold depends on battery temperature). To avoid turtle mode, utilize departure time preconditioning and charge the battery before reaching 20%. Even with preconditioning, if you drive for an extended period, the battery will cool down below 3ºC while driving and turtle mode may activate (the battery doesn't warm up while driving unless you have a 2023.5 or later model).

 

[MachhE-CT]

I recently took a 180 mile round trip with a low temp of 0 degrees F in AM and 20 degrees F on the return trip in the afternoon. I did put the car on a 6 kWh charger for 15 minutes during the stop before returning. The majority of drive was 65 mph The extended range batter was at 21% when I arrived home. We used the climate system for the entire trip set at 67 degrees. We had no issues. My Mach E is 2024 Premium Extended range.

 

[alpine_shredder]

Edited the original post to include a mitigation strategy for turtle mode. If you encounter turtle mode, pull over and turn off the HVAC for 15 minutes (or charge the battery). This allows the battery to warm up and eliminates the power limits.

The latest powertrain software incorporates automatic battery heating to +3ºC in cold conditions, but it requires the absence of an HVAC load. Turning off HVAC enables the full heater power to be utilized on the battery. Although you may notice a slight battery drain of about 3% during the 15-minute warm-up period, your range won't decrease or may even increase because the battery is being warmed, unlocking additional capacity. In theory, stopping to warm up the battery should enable you to reach 0% charge without triggering turtle mode. However, in practice, if the battery is extremely cold, you might need to stop for another warm-up if you encounter turtle mode again.

Turtle mode will activate when the battery temperature drops to 3ºC or less and the battery level is low (exact threshold depends on battery temperature). To avoid turtle mode, utilize departure time preconditioning and charge the battery before reaching 20%. Even with preconditioning, if you drive for an extended period, the battery will cool down below 3ºC while driving and turtle mode may activate (the battery doesn't warm up while driving unless you have a 2023.5 or later model).

Does anyone know how effective the 2023.5s and newer are at heating the battery while driving? If you precondition with those models, can you mitigate turtle mode in very cold temperatures (ie: were the changes in 2023.5+ enough to maintain adequate battery temperatures while driving)?

 

[redgrandam]

Does anyone know how effective the 2023.5s and newer are at heating the battery while driving? If you precondition with those models, can you mitigate turtle mode in very cold temperatures (ie: were the changes in 2023.5+ enough to maintain adequate battery temperatures while driving)?

At -21C outside mine was warming up. If I put in a charger in the navigation it would have heated up the battery a lot faster.

see the post I made about it:

https://www.macheforum.com/site/thr...s-from-an-lfp-mach-e-owner.42283/#post-909034

 

[Billyk24]

I recently took a 180 mile round trip with a low temp of 0 degrees F in AM and 20 degrees F on the return trip in the afternoon. I did put the car on a 6 kWh charger for 15 minutes during the stop before returning. The majority of drive was 65 mph The extended range batter was at 21% when I arrived home. We used the climate system for the entire trip set at 67 degrees. We had no issues. My Mach E is 2024 Premium Extended range.

What was the battery temperature during the trip?

 

[alpine_shredder]

At -21C outside mine was warming up. If I put in a charger in the navigation it would have heated up the battery a lot faster.

see the post I made about it:

https://www.macheforum.com/site/thr...s-from-an-lfp-mach-e-owner.42283/#post-909034

Thanks for sharing. Would love to see even more examples or details, but sounds promising that the 2023.5 and 2024s might have a little more capacity to keep the battery warm while driving. Hopefully the heat pump in the 2025s will help even more.

 

[Mach-Lee]

Bumping this because I’m seeing a lot of social media posts about people getting into turtle mode this past weekend.

Reminder: Keep your battery above 20% and use departure times when it’s extremely cold to avoid the severe turtle mode power limit. Plug in to Level 2 every night to keep the battery warm.

If you get turtle mode, pull over and shut off HVAC to warm up the battery.

 

[VindictivePantz]

I hit 8% last night at 5F by the time I got home. No turtle mode, but I did receive two different messages.

The first was to turn down/minimize usage of the climate system, and the second was when I parked to shut off the car, and if I wanted to continue to use the HVAC, to plug-in.

(I should've taken screenshots and note exactly when I received them, but alas, I did not.)

I did not plan on draining the battery that much and have 3+ years of winters under my belt, but the temperature dropped very quickly and took a battery that was at warm 39% with approximately 100 miles on the GOM to 62 miles on the GOM while it sat in an outdoor parking lot for ~2 hours at my next-to-last stop.

Not only do I echo Mach-Lee's 20% recommendation, but if you are out-and-about and can L2 charge here or there, it might be a good idea if temps are very low.

 

[Chris464]

Bumping this because I’m seeing a lot of social media posts about people getting into turtle mode this past weekend.

Reminder: Keep your battery above 20% and use departure times when it’s extremely cold to avoid the severe turtle mode power limit. Plug in to Level 2 every night to keep the battery warm.

If you get turtle mode, pull over and shut off HVAC to warm up the battery.

My wife encountered this last year during the subzero days we had. The problem being, it was after her work shift, so no charging option while parked in a parking ramp for work. She made it home, but ideally there would have been a way to tell the car to preheat the battery before she left work. Ideally, will keep this in mind.

Hopefully turn on the climate, get to the car and start it, turn off HVAC and let the battery warm up for 15 minutes before finally leaving?

Thanks for the work that you put into this forum.

 

[YeOldeTraveller]

I'm not saying that there is no problem. One should always carry extra resources when the temperatures get low.

However, I want to provide an additional data point. In January, I did a 13+ hour run at highway speeds with a temperatures consistently near 10F (not that cold, but it is what I was driving in.). I had no issues getting the expected charge, and no points where I was reduced in power. Based on this, I am not concerned with this car down to 10F. I will have to check my notes, but I am fairly sure I was below 20% at times on that trip. The car never sat still when not charging, so likely the battery never got that cold.

Yesterday, I arrived home at 13% in 13F weather, and the car had set long enough to allow the battery to get cold enough that there was a reduction in power, but this was only noticeable due to the jail bars on the power meter. (I think the available power was a bit over 50% of normal.) Over the course of the drive home, those bars went away, so I assume the battery warmed up enough.

It may be significant that I drive a 2024 MME Rally.

 

[mg_gti]

I hit 8% last night at 5F by the time I got home. No turtle mode, but I did receive two different messages.

The first was to turn down/minimize usage of the climate system, and the second was when I parked to shut off the car, and if I wanted to continue to use the HVAC, to plug-in.

Saw the first message yesterday when I was down to about 15% at -9C. Had been driving at highway speeds with a nasty headwind for about an hour and a half; efficiency was not good (26kWh/100km). It said something like 'To increase range consider reducing climate use'. I was pretty close to home so I didn't bother. No power reduction; got home with 13% left.

 

[Mach-Lee]

I'm happy to report from my testing that Turtle Mode has been fixed this winter. The early and severe power limits that were reported earlier in this topic are hopefully a thing of the past. The latest software (which you should all have from the 12V lockout recall) now allows a much more reasonable voltage sag under load when the battery is cold (which translates to a greater power output at low charge). I was able to drive down to 5% in -22ºF temps without a severe power limit. Turtle mode still occurred around 7% or so, but the car was still drivable and I did not experience the rapid collapse in power we had during the last two winters.

It makes sense it has been fixed at some point in 2025—we haven't had any bad turtle mode stories so far this winter with the extreme cold.

You will still get power limit of increasing severity (yellow, then red turtle), but you should be okay down to about 5% in most cases. That is much better than seeing turtle mode as early as 30%. There were some horrific cases of suddenly not being able to make it up hills and having to drive on the shoulder of the interstate to the next exit with the previous iteration.

 

[Steph]

Agreed, improvements for Sue. I am curious if I lived near a charger if it would act differently. I wish there was a way to tell it you’re going to a home charger in hopes it would allow less power reduction, if any.

 

[Maquis]

Agreed, improvements for Sue. I am curious if I lived near a charger if it would act differently. I wish there was a way to tell it you’re going to a home charger in hopes it would allow less power reduction, if any.

The primary (perhaps only) reason for turtle mode is to prevent damage to the battery, not increase range. Proximity to a charger won’t have an effect.

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