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

[awp0]

The resolution for the battery temperature is 1°C. Car scanner is converting Celsius to Fahrenheit. 1°C change is 1.8°F, so that’s the interval difference you will see between steps.

That explains it perfectly, thanks!

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[mkhuffman]

dumb question but how do you have it plugged in but not charging? I have departure times set on mine and don’t want to charge daily

I have not tried it, but I believe you can press the "Stop Charging" button after plugging in. Otherwise, it automatically charges to your target charge level.

So I just tested this and it does not work. I plugged in and the car started charging. I opened FP and pressed "Stop charging":

The car actually did stop charging and the charging LEDs turned from blue to white:

So cool! But it only lasted about 10 seconds, and the car resumed charging as normal. What is the point of the Stop Charging button if it only temporarily stops the charge? Rhetorical question.

Anyway, sorry for this misdirection. I thought it would work.

 

[nmope]

So I just tested this and it does not work. I plugged in and the car started charging. I opened FP and pressed "Stop charging":

The car actually did stop charging and the charging LEDs turned from blue to white:

So cool! But it only lasted about 10 seconds, and the car resumed charging as normal. What is the point of the Stop Charging button if it only temporarily stops the charge? Rhetorical question.

Anyway, sorry for this misdirection. I thought it would work.

This has been exactly my experience in the past. I would actually try to read the manual as paper works better for me but there isn’t one. Since I have to look it up on my phone might as well ask all of you veterans

 

[mkhuffman]

This has been exactly my experience in the past. I would actually try to read the manual as paper works better for me but there isn’t one. Since I have to look it up on my phone might as well ask all of you veterans

Yeah, I am horrible about reading the manual. When I buy something that requires assembly, I often put it together without even taking the instructions out.

Of course some projects are too serious to do that, like when I installed the Steeda sway bars. I carefully read those instructions and got help from Mark here in the forum. Really bad things could happen if you do a suspension mod incorrectly!

 

[hawkeye3point1]

dumb question but how do you have it plugged in but not charging? I have departure times set on mine and don’t want to charge daily

I had the same dumb question, not such a simple answer though. I was trying to get the car to maintain battery temp (been in the teens recently) without charging, with an L1 EVSE.

Tried the "Stop Charging" approach and setting "Charge Time" to the one hour minimum, but that seemed to prevent any battery warming while on plug.

The only way I could get it to work was to set Charge Level to the bare minimum, which is 50%. Luckily I was just above that, and it worked.

"Preparing to Drive" showed up in FordPass and I could verify via CarScanner, and a power monitoring WIFI plug. PTC draws 1 kWh, WIFI plug shows 1.3 kWh, HVB power was .300 kWh (idle draw), and HVB warmed from 26.5F to 41F in one hour, then the car went back to sleep.

Easy peasy.

 

[Mach-Lee]

Idle Reserve Capacity Test

Today's test was relatively simple, see how long the car could stay on with heat in the cold. Imagine a scenario were you are stuck on a highway in snow or ice storm, how long will you have heat?

I parked the car outside for 10 hours with the heat on in single digit (ºF) temps. Heat set to my usual 68ºF AUTO 1 setting. Heated seats/wheel and all other accessories off.

In 10 hours, it used 28% of the battery. That means with a 100% charge you could last about 36 hours idling with heat on. If the BMS is to be trusted, I used 24.5 kWh, so average power use was about 2.5 kW. That figure can go up a lot temp is lower or the wind is blowing hard.

The average cabin air temp was stable around 75ºF during the test, which equated to cabin surface temperatures of 65-70ºF (air temp will always be higher than surface temps). The Mach-E interior temp sensor (by the mirror) was reading 70ºF. The back seat was only about 57ºF (noticeably colder than up front). A higher blower speed would have helped even out the cabin temps and reduce stratification. If you have rear seat passengers you should use AUTO 2 or 3 to help push air back there.

The battery temp started at -1ºC and ended at -6ºC. I wasn't recording the whole time so I'm not sure if it was heated or not during the test, but my guess is no. That means the battery only lost 5ºC temperature in 10 hours. Some heat radiating down from the cabin floor may have also helped slow loss. Overall the temp drop was much slower than what I've observed when driving, it seems the air blowing under the car while driving drives significant battery heat loss compared to being stationary.

Findings:

• Battery dropped 2.8%/hr maintaining a warm cabin while stationary
  • Do the math, but this means a 100% battery provides 36 hours of heat @ 2.5 kW
• A 68ºF setting resulted in a ~67ºF cabin with 75ºF air temps
• Rear seat ends up significantly colder than front seats
• Battery cools off significantly slower while parked compared to while driving
  • Heat loss while driving may be up to 2x higher than when stationary

 

[mkhuffman]

I did a similar, but much shorter, test last year after that big snowstorm stranded people on I95 in VA. I also found it used about 2.5 kWh to keep the cabin warm. So if you use seat heaters and lower the cabin temp, you could stretch that out even more. If you have a decent charge, you can last longer than an ICE vehicle, and you don't have to worry about carbon monoxide poisoning, which has killed people stuck in deep snow.

 

[Mach-Lee]

BTW - if I read correctly, all your testing was done with the target charge reached, so no battery charging was happening. If that is correct, if you plug into L1 with a battery that needs to be charged, will the charging process supersede the preconditioning process?

I assume that is why we previously thought no preconditioning would happen on L1. The charging speed is so slow, it really cannot add charge to the battery and precondition at the same time, so it prioritizes charging. That is what most of us would want it to do, I think.

This got chosen for the next test. You were correct.

120V Charging/Heating Test

L1 charged with the battery at -6ºC. Battery charged for about 4 hours without increasing in temperature much. As soon as the target SoC was reached, the coolant heater started at 1 kW and heated the pack up from -3ºC to 5ºC, which took about 75 minutes. The EVSE input was constant at 1.1 kW the entire period.

The battery will not heat on 120V until charging has finished.

Coolant heater always runs at 1 kW while plugged into 120V instead of 5-6 kW. The only exception is remote start, which allows full output with corresponding battery drain.

This is kinda interesting, you can see the battery energy increase from charging, and then from heating at 1 kW. The slope while heating is a lot steeper even though the power input is the same, this shows how effective heating can be for increasing pack energy. The SoC goes down slightly since the pack can actually hold more energy when warm.

Summary:

• When using a Level 1 (120V) EVSE, the pack will charge first, and then heat.
• When using a Level 2 (240V) EVSE, the pack will heat first, and then charge.

Conclusions:

• The Mach-E prioritizes charging on 120V, and will only heat the pack after the charge target is reached.
  • This behavior is the opposite of 240V charging.
• If you use 120V charging, make sure you give the car enough plug time so it can heat up the battery at the end of the charge cycle. Allow an extra hour or two for heating.
• Setting a lowered charge limit that can be accomplished overnight may be beneficial so the pack is heated before the next drive.
  • If the charge limit is not reached, the battery will not be heated. Avoid endless charging.
  • Lowering the charge limit below current SoC can force a switch from charging to battery heating on 120V.
  • Recommend you allow charging 24/7 on 120V, and set a reasonable limit in the 70-90% range.

BTW, doing this test reaffirmed that 120V charging and heating is REALLY DAMN SLOW compared to 240V (only about 1% per hour). Major props to those of you that put up with 120V and wait all day and night for your car to charge.

 

[mkhuffman]

• When using a Level 2 (240V) EVSE, the pack will heat first, and then charge.

If we use a 11 kW L2 charger, will it heat and charge at the same time? It only needs max 5 kW for the heater, so the remaining 6 kW can go to the battery. Sorry if I missed a post about that previously...

 

[Guss-E 2021]

Idle Reserve Capacity Test

Today's test was relatively simple, see how long the car could stay on with heat in the cold. Imagine a scenario were you are stuck on a highway in snow or ice storm, how long will you have heat?

I parked the car outside for 10 hours with the heat on in single digit (ºF) temps. Heat set to my usual 68ºF AUTO 1 setting. Heated seats/wheel and all other accessories off.

In 10 hours, it used 28% of the battery. That means with a 100% charge you could last about 36 hours idling with heat on. If the BMS is to be trusted, I used 24.5 kWh, so average power use was about 2.5 kW. That figure can go up a lot temp is lower or the wind is blowing hard.

The average cabin air temp was stable around 75ºF during the test, which equated to cabin surface temperatures of 65-70ºF (air temp will always be higher than surface temps). The Mach-E interior temp sensor (by the mirror) was reading 70ºF. The back seat was only about 57ºF (noticeably colder than up front). A higher blower speed would have helped even out the cabin temps and reduce stratification. If you have rear seat passengers you should use AUTO 2 or 3 to help push air back there.

The battery temp started at -1ºC and ended at -6ºC. I wasn't recording the whole time so I'm not sure if it was heated or not during the test, but my guess is no. That means the battery only lost 5ºC temperature in 10 hours. Some heat radiating down from the cabin floor may have also helped slow loss. Overall the temp drop was much slower than what I've observed when driving, it seems the air blowing under the car while driving drives significant battery heat loss compared to being stationary.

Findings:

• Battery dropped 2.8%/hr maintaining a warm cabin while stationary
  • Do the math, but this means a 100% battery provides 36 hours of heat @ 2.5 kW
• A 68ºF setting resulted in a ~67ºF cabin with 75ºF air temps
• Rear seat ends up significantly colder than front seats
• Battery cools off significantly slower while parked compared to while driving
  • Heat loss while driving may be up to 2x higher than when stationary

Convective heat loss is no joke and really difficult to insulate against (even for humans). @Mach-Lee these posts are gold. Thank you.

 

[Terence Murphy]

BTW, doing this test reaffirmed that 120V charging and heating is REALLY DAMN SLOW compared to 240V (only about 1% per hour). Major props to those of you that put up with 120V and wait all day and night for your car to charge.

and day and night and day and night. And another day and night.

 

[emichnov]

Summary:

• When using a Level 1 (120V) EVSE, the pack will charge first, and then heat.
• When using a Level 2 (240V) EVSE, the pack will heat first, and then charge.

Conclusions:

• The Mach-E prioritizes charging on 120V, and will only heat the pack after the charge target is reached.
  • This behavior is the opposite of 240V charging.
• ...
• Setting a lowered charge limit that can be accomplished overnight may be beneficial so the pack is heated before the next drive.

So sorry if I am misunderstanding this explanation, but if I plug in with 240V level 2 charger, you're saying that the pack will heat first before charging? And, once the target charge rate is reached, the pack will continue to heat itself for as long as it is plugged in?

 

[Mach-Lee]

So sorry if I am misunderstanding this explanation, but if I plug in with 240V level 2 charger, you're saying that the pack will heat first before charging?

Yes, if necessary.

And, once the target charge rate is reached, the pack will continue to heat itself for as long as it is plugged in?

Yes, if you are inside the allowed charging hours. See #111

 

[Mach-Lee]

Turning HVAC Off Heats the Battery?

FYI, I just observed this happening on my car. If the battery is cold enough, the ignition is ON, and you turn OFF HVAC, the battery may immediately begin heating up to 13ºC/55ºF. After you turn off HVAC you will hear a coolant pump start humming and gurgling noises coming from the firewall. This may last anywhere from 15-45 minutes. I was plugged into a L2 EVSE at the time (not charging), but I'm not sure if that's a requirement or not (requires further testing). I'm also not sure if this works while driving or if you have to be parked. Hoping some of you may also want to test this.

This could be useful if it works unplugged. You could potentially stop and warm up the battery before L3 charging if you wanted a faster charging speed (such as when the station charges by the minute), but I'm not sure how many minutes it would save over just doing it right after plugging in. Personally I would prefer parking and warming it up fully before plugging in.

 

[Terence Murphy]

Does that mean if you leave your HVAC off and remote start the car, it will warm the battery on demand?

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