PSA: Keep The Battery Warm So You Have Enough Cabin Heat

[mccdeuce]

about 3 kWh usage to complete a full departure time

super useful piece for me thank You!

due to current moving situation we are on Level 1 charging.
but I got an Anker F3800 on kick starter (to be installed in next house) but currently dragging it out to warm the battery before I do my 200 mile commute. Should be able to warm the battery and cabin!

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[music_cities]

Last winter I had to park at a friends house for 8+ hours outside in single digit temps. When I went to drive home I remote started twice. The cabin was warm when I got in but I got no heat at all the entire drive home. The windows were fogging up. I assume it was trying to heat the battery. This is just plain dangerous.

Based on stories like this I have adopted an approach of dressing warm, setting the cabin temperature to minimum (15.5C, I guess 60F), and directing all the airflow up to the front window (defrost). I had no problem at all on a 70km drive in -30C (I guess -22F) a couple of days ago. 15.5 was quite comfortable, mind you I also put a 12V electric blanket on my lap.

I don't know what the humidity was, and I was preconditioned. I'd like to try the same experiment on a more humid day without preconditioning.

 

[EasyPass]

Wanted to write a note about this since many people are currently experiencing extreme cold temps (below 14ºF/-10ºC). In a nutshell:

Keeping the battery is warm is important so you have enough cabin heat!

If the battery is cold, the Mach-E will steal your cabin heat to warm the battery. The heater is shared between the battery and cabin. Battery temp takes priority over cabin temp. As a result, if the battery is cold, you may be cold. You may notice inconsistent heat at different times. It's related to the battery temperature.

As a reminder, follow these tips:

• Plug in the car when it's below freezing as much as possible to keep the battery warm. Every night.
• Set a departure time before any trips longer than approximately 15 minutes (warms the battery up fully).
• Use a Level 2 charger instead of Level 1 (L1 doesn't provide enough heating power).
• Make sure your EVSE is set to allow charging anytime and your charging hours aren't overly restrictive (≥8 hours per day).
• If you can't plug in, then run a remote start for 10-15 minutes before leaving. It's much easier to warm the cabin up when the car is stationary vs. driving.
• LIMIT FAN SPEED to a medium level or less (≤3). High fan speeds actually cool down the cabin in extreme cold.
• Use a moderate heat setting of 65-72ºF (18-22ºC) to avoid excessive fan speed and energy loss. Turning it up hotter won't help.
• Park in a garage rather than outside. This can keep the battery a lot warmer.
• If possible, drive slower. This will reduce convective heat loss.

Owners are experiencing lack of heat when parking the vehicle outside unplugged, or when they have extremely restrictive charging hours that don't allow the battery to draw power to for heating. The EVSE must allow charging at the time you are performing a departure time, or it won't work.

If you have a time-of-use rate plan, you may need to allow some charging to occur during peak times so the battery can heat. The small added expense from this may be well worth having heat. I see about 3 kWh usage to complete a full departure time (typically costs <50¢/day). I would avoid the highest peak times, but if you have a mid-peak rate, that would be okay for preconditioning use because the usage will be small. In cold weather, I recommend setting a departure time at least once a day before the anticipated time of vehicle use (battery stays warm for hours afterwards). If you don't have a regular schedule, you can set a battery-only departure time to reduce energy use. For more information about how/when to set departure times, see my other topic: Mach-Lee's Cold Weather Charging Strategies

For example, I have my EVSE set to allow charging at any time 24/7 and my charging hours in the car are set from 10PM to 10AM. I would set it this way even if my rate plan ended at 6 AM. The car usually only charges a for a couple hours (always done before 6 AM), but can automatically heat itself if necessary up until 10 AM. Departure times will still work anytime because the EVSE allows charging.

The heater in the Mach-E is undersized for extreme cold (only 5 kW) and may not be able to keep the cabin fully warm in temps below 5ºF/-15ºC even after following all the tips. Dress warmly. The minimum operating temperature of the Mach-E is around -31ºF/-35ºC, you may have zero cabin heat available around that temp. If the battery gets too cold, you'll enter turtle mode and have almost no power (can't maintain speed). Full heater output will be diverted to the battery, but in extreme cold that might not even be enough.

Cold weather requires some changes when driving an EV. You're living plug-to-plug in the extreme cold, and the ability to draw Level 2 power for heating becomes critical.

Here is a scenario I'd like an opinion on that I will be having to accommodate soon:
On January 28 I will drive at 5:30am from home to a pickup spot that is 20 miles away and park my MME outside till late on February 2nd. During that time I will be away on a bus trip with my ski club.

I can leave home with a full overnight L2 charge, but obviously have no control over the temperatures that the vehicle might endure in the interval. For example, currently temps are in the teens and will vary between that and single digits over the next few days. So the car may be in frigid conditions outside for up to 5-6 days. Do I need to take any precautions, or even worry about this situation at all? Should I just plan on a remote start on the return bus trip a little before arriving back at my car and call it a day? I assume that the vehicle remains locked following a remote start. TIA.

 

[bbulkow]

You’d think Ford would have done extreme cold testing that many of its owners experience. They would come to the conclusion the system in the Mach E is not adequate as shipped. Too bad.

Last winter I had to park at a friends house for 8+ hours outside in single digit temps. When I went to drive home I remote started twice. The cabin was warm when I got in but I got no heat at all the entire drive home. The windows were fogging up. I assume it was trying to heat the battery. This is just plain dangerous.

Thanks for giving this info to others that may not understand they may actually need to put in effort to stay warm in a car….

From this write-up, it seems obvious Ford did extreme cold testing, and that's why they have software to specifically make sure the battery gets priority over the cabin when you need heat.

And correctly so: I'd rather be rolling cold then stuck, and I'd rather be reliably rolling than stressing a part to failure, and it seems they part they put in gives enough oompf to keep you going, even if it's optimized for temps over 0 F

 

[Mirak]

In addition to @Mach-Lee’s excellent suggestions, if you need to drive your car without pre-planning a departure time (like any non-robot human being) just use the handy “precondition now” button in FordPass.

 

[Mach-Lee]

So if in this situation again, would the best move be to turn off auto shut off and turn the car on a few hours before you planned to leave?

Alright, I tested that. Battery was at 0ºF/-18ºC. I manually turned on the car and left it with the HVAC on my normal settings. The cabin warmed up and reached equilibrium after 30 minutes. I let it go another hour, however no battery heating was observed with HVAC on, still at -18ºC. I then turned off HVAC, and the battery started heating, but only to about -7ºC. That's probably the minimum acceptable temp. I'll maybe post a full write up later.

So you could turn the car on with HVAC off for 40 minutes, then go back and turn on the HVAC for 20 minutes before leaving. The battery will still be cold, just not extremely cold.

 

[Mach-Lee]

The one question I have is how do you know if the preconditioning is actually happening? I have it set to precondition every morning but since I'm retired, may not drive for days at a time. It would be nice to know if it is in fact warming the battery. Suggestions?

If you have a smart EVSE you can watch the power usage on the graph. You can hear the battery coolant pump running when it heats if you are near the car at the right time. You'll see "preparing for drive" in Fordpass during battery heating. And if you use a scan tool, you can watch it happening in the data.

@Mach-Lee Thanks as always, very informative! One question: My TOD pricing cheap window is 10PM - 6AM, so I have my MME set to charge during that time. I do not restrict the time in my EVSE at all. Will the MME kick in to warm the battery whenever it needs to, or only during my home location set charging window of 10PM - 6AM?

Only during the charging window. So you should extend the window or use departure times.

Here is a scenario I'd like an opinion on that I will be having to accommodate soon:
On January 28 I will drive at 5:30am from home to a pickup spot that is 20 miles away and park my MME outside till late on February 2nd. During that time I will be away on a bus trip with my ski club.

I can leave home with a full overnight L2 charge, but obviously have no control over the temperatures that the vehicle might endure in the interval. For example, currently temps are in the teens and will vary between that and single digits over the next few days. So the car may be in frigid conditions outside for up to 5-6 days. Do I need to take any precautions, or even worry about this situation at all? Should I just plan on a remote start on the return bus trip a little before arriving back at my car and call it a day? I assume that the vehicle remains locked following a remote start. TIA.

The cold will not harm the big battery while parked. I would make sure your 12V battery is fully charged before the trip however so it doesn't freeze.

Unless you have time to sit there and be cold, then I would just do a remote start for 15 minutes before leaving.

 

[Logal727]

Surely it gets pretty cold in Michigan?

 

[Mopey]

...So the car may be in frigid conditions outside for up to 5-6 days. Do I need to take any precautions, or even worry about this situation at all? Should I just plan on a remote start on the return bus trip a little before arriving back at my car and call it a day? I assume that the vehicle remains locked following a remote start. TIA.

The car will be fine left on its own for several weeks, in even extreme cold. I've left mine at the airport for several weeks in mid Alaska winter. However, the 'remote start 15 minutes prior to returning to your car' may not work. I've found with my car, the 12v battery may go into sleep mode and not allow a remote start with FordPass. That seems to be the case after 5 or 6 days, but I haven't done any formal tests to determine the exact length of time before the 12v sleeps vs. outside temps. This Christmas I left the Lightning at the airport for 10 days and upon return the FordPass remote start didn't work, nor did the departure time scheduling - even with 'Pre-condition Cabin While Unplugged' selected. However, even though unplugged, the truck started fine manually, once inside the vehicle.

 

[Goodsam]

I would make sure your 12V battery is fully charged before the trip however so it doesn't freeze.

Will our Ford.com account page show the 12V charge level? But if vehicle goes to sleep, that will not be available?

 

[smunro622]

Thank you great info as we have Zero here in Michigan I have 2 departure times setup to warm and is always plugged in…

 

[elbo]

if you have the glass top, this thing has done more for me for cabin heat comfort than any preconditioning ever has in extreme cold

 

[MME Farmer]

Based on stories like this I have adopted an approach of dressing warm, setting the cabin temperature to minimum (15.5C, I guess 60F), and directing all the airflow up to the front window (defrost). I had no problem at all on a 70km drive in -30C (I guess -22F) a couple of days ago. 15.5 was quite comfortable, mind you I also put a 12V electric blanket on my lap.

I don't know what the humidity was, and I was preconditioned. I'd like to try the same experiment on a more humid day without preconditioning.

Just what you'd expect from a 60k car!

 

[GreaseMonkey]

Yesterday, I experienced first hand why following @Mach-Lee advice (if you can) is so vital.

I took the same trip to my parents’ house that I take every weekend. Typical energy consumption year round is 9% battery for a round trip. Given the info on this thread, I took a measurement of HVB temp before leaving: 41-45F (car is parked six floors up in the building’s unheated garage. Outside ambient temp was -4F with extreme high wind. Left with ~35% SoC. I parked at my parents’ outside for 2.5 hours. Right before leaving, took a battery temp measurement and it was 15F. By the time I made it home, I had consumed 22% battery, so rolled in at ~12% SoC. I was alarmed at how low the battery SoC dropped and didn’t want to leave it this low. So I drove 0.5 miles to my local WholeFoods where there are four EVgo chargers. During my drive, I encountered a slow moving BMW and wanted to overtake him, but the car went into turtle mode and power was significantly reduced. At EVgo, all chargers were occupied. Waited for my turn. Measured the HVB temp again, and recorded 25F. Within the first 15 min of waiting, my SoC dropped from 12% down to 9%!! Also, the entertainment feature (games) was grayed out and inoperable. To conserve what is left of my battery, I shut everything down and sat in the car with my jacket and gloves on. I later plugged with no issues, had a beer while watching the cowboys getting their asses handed to them, and the car charged and was back to normal.

 

[benk016]

I spent all day Saturday out and about while it was below freezing with windchills below zero.

Started the day off with a preconditioned battery and things were fine. Half way through the day, even with remote starts before each trip, the cabin basically had no heat except from what I got during the remote start. I also had about 50% jailbars the entire day after the first stop where I shut the car off for a bit. By evening time after a few minutes of driving the windows were fogging up because the cabin was cooling off so fast.

Ended up driving 75 Miles around town, and used 51kWh of energy from the pack.

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