Mach-Lee's Mach-E Cold Weather Testing [Taking Requests]

[Mach-Lee]

I understand just thinking of setting departure time in fordpass, 15 min before I leave , I don't know if it will work ?

Congratulations, I decided to test that just now. The answer is yes, you can heat the battery if you set the cabin temperature to OFF in the departure times setting. If you set a cabin temp, that takes priority and the battery will not be heated in that short time. After figuring that out, I set a departure time for 8:00 at about 7:40. In 20 minutes the battery warmed up from 34ºF to 59ºF, so it is worthwhile to do that. Rate is about 75ºF per hour, do the math to calculate time to 59ºF from current temp. The heating and EVSE will shut off once the pack reaches 59ºF/15ºC. The cabin will be cold though since it will only heat one or the other at a time.

Power used for the below was about 2.6 kWh.

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[Mach-Lee]

I recall someone reporting to fully pre-condition the battery was ~5kwh, so given a ~5kw PTC, you need 1hr to fully pre-condition the battery + ~10min for the cabin. That said if you keep it on plug, I think it keeps it above 32F, so any amount of pre-condition will bump you over 32F if you are concerned.

See above, it takes about 20 minutes and 3 kWh of heating to go from 32ºF to 59ºF. PTC was running at about 6.2 kW due to colder inlet temps.

 

[hawkeye3point1]

See above, it takes about 20 minutes and 3 kWh of heating to go from 32ºF to 59ºF. PTC was running at about 6.2 kW due to colder inlet temps.

Did you happen to record the GOM delta?

 

[AlpaChino]

I think it will heat it to about 15°C/59°F from past experience, but I’ll log it.

The heater isn’t big enough to also heat the pack while driving. 100% is going to the cabin with no heat to spare.

@Mach-Lee Your write up and research is simply fantastic. Thank you, sincerely.

In your opinion, do you think Ford could add a reserve heater in the future that while drawing additional power during a preconditioning, could not only get the battery up to temp quickly, but theoretically be leveraged at a lower power to maintain the battery pack temp enough to offset the massive capacity loss in low temps and potentially result in a net gain vs a single heater?

Even if it took 30 minutes of 30+ amp draw just to heat the battery during a preconditioning period, I'd gladly do it if it resulted in a 40-60 mile range increase when each mile matters in the Midwest.

Thoughts? Thanks as always.

 

[Mach-Lee]

Did you happen to record the GOM delta?

I didn't unfortunately, maybe next time. It's complicated because it started charging the battery a little bit while it was heating (charger does it's best to match the heater load but sometimes it has to bump up to the next higher amp draw). I did see about a 4 kWh increase in energy though. If extrapolate that for a fully charged battery (8 kWh) and use my efficiency I get an estimate of +14 miles. I'm also not on the latest GOM software that works better yet. I don't really use the GOM anyway, I use % and calculate since I'm more accurate.

@Mach-Lee
In your opinion, do you think Ford could add a reserve heater in the future that while drawing additional power during a preconditioning, could not only get the battery up to temp quickly, but theoretically be leveraged at a lower power to maintain the battery pack temp enough to offset the massive capacity loss in low temps and potentially result in a net gain vs a single heater?

Even if it took 30 minutes of 30+ amp draw just to heat the battery during a preconditioning period, I'd gladly do it if it resulted in a 40-60 mile range increase when each mile matters in the Midwest.

Yeah, I think they need a second heater of some form so they can do simultaneous cabin and battery heating. Hopefully a rework of the plumbing and heating is top engineering priority for the next Mach-E refresh. I'm wondering if Ford benchmarked the Mach-E against the Model Y thinking it only had one PTC heater (true) but missed the fact that Tesla can also heat the battery with waste heat generated by stalling the motors.

See above, it's not going to be as much range increase as you think. I need to do more verifying but +14 miles estimated at 34ºF bat temp. If the battery was very cold (like -10ºF) you may see +35 miles. So it's something but not a huge increase. If you are going on a trip that will use DCFC I would also precondition before leaving so you don't have to wait as long.

 

[Mikeg]

Very timely topic...I am about to attempt a road trip from cold north to sunny south.
ABRP has the following distances planned for me between stops:
111 miles
164 miles
165 miles
The temperature in the above segments will range from 5F to 15F.
2022 mach e gtpe.
4 people.
cabin temp 64F
65mph max speed

Question: Are my distances too long between stops? I expect to charge to at least 90% at each stop.

 

[Mach-Lee]

Very timely topic...I am about to attempt a road trip from cold north to sunny south.
ABRP has the following distances planned for me between stops:
111 miles
164 miles
165 miles
The temperature in the above segments will range from 5F to 15F.
2022 mach e gtpe.
4 people.
cabin temp 64F
65mph max speed

Question: Are my distances too long between stops? I expect to charge to at least 90% at each stop.

Yes, I would try to keep your legs under 120 miles. Make sure you are entering the 5°F into ABRP so it calculates properly.

 

[Mikeg]

what about drafting big rigs? does that help to increase range?
Also, lowering speed from 65mph to 60mph. Will that help?
my longest leg right now looks from Huber heights in Dayton to Clarksville. 2nd longest is Toledo Blue Hero rest stop to Huber heights in Dayton. Anybody done those routes? any suggestions or hidden chargers that you can share?

 

[MWMME]

Figured I'd make this topic to share my cold weather testing data this winter. It's going to be below zero Fahrenheit here on several days this week, and I'm sure there will be much more this winter (lowest we get is about -25ºF). But I wanted to offer to test things that people are interested in with the cold weather and share the results. So if there's something you wanted me to test in cold weather, let me know and I'll see what I can do.

Current conditions:

Here's a trip I took last night to look at cabin temps. I started with a cold car in my garage, no preconditioning whatsoever. I drove a loop with mixed highway and interstate driving. 2022 ER AWD.

12/19 Trip Summary:
Outdoor temp: -2ºF/-19ºC
Wind: calm
Distance: 90.3 mi
Duration: 83 min
Displayed efficiency: 1.9 mi/kWh
Average speed: 65 MPH

Starting conditions:
Cabin temp: 29.3ºF
Battery temp: 30.2ºF
Displayed SoC: 70.5%
kWh to empty: 48.956

Ending conditions:
Cabin temp: 64.4ºF
Battery temp: 33.8ºF
Displayed SoC: 8.5%
kWh to empty: 8.226

Calculated stats:
Battery used: 62%
Energy used: 40.73 kWh
Calculated efficiency: 2.2 mi/kWh
100% range at -2ºF: 146 miles (52.7% of EPA)
100% energy available: 65.7 kWh

HVAC set to 68ºF AUTO 1

FYI my temperature sensor was placed on the passenger seat just under the headrest. It wasn't the best placement so it probably had a bit more thermal lag due to the seat in close proximity. So in reality the air temp was a bit warmer than the temp sensor showed. I will work on a better sensor solution for future drives.

Notes:

I drove an out and back leg from my home to the interstate, so there's a mix of highway and interstate driving. No wind, almost no traffic, perfect test conditions. Temps variable from -4º to 0ºF. BlueCruise at 75 MPH on the interstate.

The whole car/battery started at about 29ºF in my garage, I got in and drove with minimum idle time beforehand. Within several minutes the windows were already fogging up badly, I had to use MAX Defrost to clear them, which worked well. The initial humidity in the cabin was very high for some reason which caused fogging, even though I had dry feet and mats. Potentially there was some moisture in the A/C core that took about 30 minutes to purge. It took about 30 minutes before I felt "warm enough" while driving, the rest of the time I was slightly chilly but acceptable (wearing a jacket). Throughout the drive, the windows periodically fogged up a little bit for only a couple minutes at a time before clearing up. It was obvious the fresh air damper was opening and closing, when closed the fog would form very quickly. You can see the humidity spikes on the graph when the damper closed.

On the interstate the pack actually cooled down a few degrees to a low of 28.4ºF. Interestingly, the split between minimum cell temp and maximum cell temp increased with time. The coldest cell was 26.6º while the warmest was 39.2º, a difference of 12.6º. At the end of the drive I saw 32/50ºF, a difference of 18ºF or 10ºC.

Slowing down with 1PD I was shocked at how much regen the car allowed with a pack below 0ºC, I saw up to 75 kW. That's crazy high and really not good for the pack because of the lithium plating risk. The regen limit was adjusting with pack temp, but I'm very skeptical that this is an acceptable amount for pack longevity. Teslas will have almost no regen when the pack is below 0ºC but I was getting almost the full amount here. Maybe the battery engineers know something I don't, but this was my biggest concern/finding of the drive. The battery temp also rapidly increased after regen events, the cells don't want to accept all that power so a lot of it gets turned into heat. Regen is why the pack temps went up at the end of the drive.

The navigation said I wasn't going to make it back home and wanted to add a charging stop, but I made it back with 9%. I was targeting 10% arrival, so I was close. The recorded mileage was also slightly less than what Google Maps got, that's probably nominal. There is also an efficiency discrepancy with the "This Trip" screen for some reason. I get 2.2 mi/kWh from the raw battery data but the screen said my trip was 1.9 mi/kWh. Not sure what's up with that. The overall efficiency and range performance was about what I expect for these temps (getting about half of the EPA rated range). With a full battery my actual range would be less than 150 miles with the extended pack.

Findings:

• The heater was pegged at maximum output the entire drive (about 5.4 kW)
• The battery was never heated the entire drive
• The battery didn't really warm up while driving (except from regen), it actually got a couple degrees colder on the interstate.
• Regen limit with a freezing battery was astonishingly high at 75 kW!
• Significant cell temperature variations can occur in the pack after driving, this is also not very desirable.
• The HVAC system closes the fresh air damper periodically to increase heat, but the cabin humidity spikes and windows fog.
• Initial humidity in the car can be an issue, it took about 30 minutes for the cabin to dry out.
• Cabin temperature was very slow to rise, takes at least 30 minutes for the cabin to warm to an acceptable temperature with no preheat.
• The navigation estimate for arrival percentage is off, about 10% error in the conservative direction.
• The efficiency calculated by the trip computer does not match the energy used data from the pack (1.9 vs. 2.2 mi/kWh).
• The actual range and efficiency is about what I would expect in sub-zero temps.
• The trip mileage is slightly low compared to Google Maps.

Conclusions:

• The cabin heat is pretty much at its limit around 0ºF. Window fogging and cabin comfort will likely go downhill from here as it gets colder.
• Wet feet and/or snow on the floor mats will increase fogging considerably.
• The new HVAC calibration helps improve heat but is still a bit chilly when below 0ºF.
• Trying to use recirc is out of the question at these temps, the windows will fog up almost immediately.
• I'm very concerned about the regen limit being so high with a cold pack. This could permanently damage it. Tesla does not allow virtually any regen at the same battery temps. It should be limited to 20 kW or less with a freezing pack IMO.
• Preconditioning to warm up the battery is highly recommended to prevent pack damage during regen.
• The trip computer and navigation seem to contain moderate errors in the conservative direction.

I plan on repeating the same trip after Preconditioning to see the difference.

mirrors my real world experience on two recent trips here in Canada. Range loss approaching 50% at -18 C, cold batteries, and window fogging issues. I feel like this car was not tested in these conditions, or it was tested and Ford decided the market in northern climates was small enough to ignore these issues in order to get the car to the market.

 

[MWMME]

Nice write up. I wonder why the humidity levels were so high early on, would have thought humidity would be low being so cold. Only thing I can think of is if the car was cold then brought into a warmer garage when parked prior to this and condensation formed on the colder surfaces?

Also surprised to see the temp delta between cells, would have thought they'd be much closer as they are probably all in a common cooling loop.

Appreciate the observations, interesting data.

Snow. It’s always on your boots, melts and eventually evaporates in the car.

 

[Mach-Lee]

Here's a quick comparison of the cabin warm-up speed between being stationary in a 27ºF garage and driving without preconditioning at -2ºF. Sensor in same spot. You can see the warmup time if you don't precondition and just drive is about 3x longer to reach the same temp. Last little bit while driving is very slow due to being close to thermal equilibrium. Better to heat it up while stationary since there's no wind to take the heat away. I know they're not at the same exterior temp but this is real-world usage where you might park in a warmer garage at night.

 

[HGxxx]

Congratulations, I decided to test that just now. The answer is yes, you can heat the battery if you set the cabin temperature to OFF in the departure times setting. If you set a cabin temp, that takes priority and the battery will not be heated in that short time. After figuring that out, I set a departure time for 8:00 at about 7:40. In 20 minutes the battery warmed up from 34ºF to 59ºF, so it is worthwhile to do that. Rate is about 75ºF per hour, do the math to calculate time to 59ºF from current temp. The heating and EVSE will shut off once the pack reaches 59ºF/15ºC. The cabin will be cold though since it will only heat one or the other at a time.

Power used for the below was about 2.6 kWh.

Thank you for testing that, I did that yesterday for 15 min. I may be imaging it but I felt the cabin was not as cold even though the climate control was off, maybe due to a warm floor.

 

[Calgary MACH E]

I'll tell you what's happening here in -31 celsius Calgary. Barely over 200km on a long range.

Some have complained about window frost... We don't have that issue and we don't need to use full defrost either.

It's a dry climate I guess... But regardless.. we first press the full defrost button and then adjust fan lower to between 4 and 6. That takes care of anything and doesn't run the fan at full tilt.

Drive safe!

 

[Guss-E 2021]

Congratulations, I decided to test that just now. The answer is yes, you can heat the battery if you set the cabin temperature to OFF in the departure times setting. If you set a cabin temp, that takes priority and the battery will not be heated in that short time. After figuring that out, I set a departure time for 8:00 at about 7:40. In 20 minutes the battery warmed up from 34ºF to 59ºF, so it is worthwhile to do that. Rate is about 75ºF per hour, do the math to calculate time to 59ºF from current temp. The heating and EVSE will shut off once the pack reaches 59ºF/15ºC. The cabin will be cold though since it will only heat one or the other at a time.

Power used for the below was about 2.6 kWh.

This information is very useful. I've a departure schedule for the morning (starting in the garage, plugged in) and for after work when the car has been sitting in the lot all day.

It's now dark or near dark when I leave the office; i.e. colder out so I'm inclined not to heat the cabin and favor the battery. Heating the seats and steering wheel takes no time and really takes the edge off the chill imo.

 

[RickMachE]

what about drafting big rigs? does that help to increase range?
Also, lowering speed from 65mph to 60mph. Will that help?
my longest leg right now looks from Huber heights in Dayton to Clarksville. 2nd longest is Toledo Blue Hero rest stop to Huber heights in Dayton. Anybody done those routes? any suggestions or hidden chargers that you can share?

Drafting has nothing to do with EVs, it is more efficient. Same with slowing down. Both will help, but watch for gravel off the big rig taking out your windshield.

I have done SE Michigan to Huber Heights numerous times (though not from Blue Heron). In the winter it is a challenge from SE Michigan because there's not much in Toledo beyond a Chevrolet dealership. When I did it last March, I charged a little at the dealership, then headed south. Limited heating until I was sure we'd make it. In Lima, Apollo Career Center is around 43kW. Not cheap, hit it once, that's why I stopped at the Chevrolet dealer last year.

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