What Would You Do If Stuck?

[ChasingCoral]

Yeah, that’s 7kw at 240VAC not 400VDC.
Also that’s a coil in air; not a coil in coolant. Very different designs.

At 400VDC 7kw is 17.5 amps; basically a 22 ohm resistor equivalent.

There’sa question: which battery is used for heating? I assumed it was the 12v. I thought the 400v was only used for driving.

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[louibluey]

There’sa question: which battery is used for heating? I assumed it was the 12v. I thought the 400v was only used for driving.

The cabin coolant heater is powered by the HV traction battery, all of the related components, pumps, diverter valves, fans, etc, are 12V.

The cabin coolant heater circuit provides warm coolant to the heater core to warm the passenger compartment. An auxiliary high voltage cable connects the high voltage battery to the cabin coolant heater.

 

[Jimrpa]

Very doubtful the Mach E heater is anywhere near 7kW. Here's what a 7500W stand-alone heater looks like:
https://www.googleadservices.com/pa..._Jr1AhWHTDABHY6iBSUQ9aACegQIARA-&dct=1&adurl=

Yes, but remember people want to replace the frunk with a heat pump ???

 

[BalsaDust]

When I was working for the government, first thing I was given was a "to go bag"
It had sweat pants, sweatshirt, flight suit, two MRE's, flashlight with extra batteries, and a box of hand warmers the type you squeeze and they heat up.
In the ten years I was contracted out I only needed it once when posted at Canada Air Force Cold Lake.
Ever since then (late 70's) I always carry similar stuff in a "to go bag" in every car I have owned and fortunately I have never needed to use them.

If you have it you most likely will never need it, but if you don't have it... well you might wish you did one day!

Tony

 

[Carsinmyblood]

How incredibly soft we've become. It's winter, wear winter clothing.

Has no one gone camping in the winter? Once upon a time the west was settled with nary a heater to be found. ...Ok, yea, they slept with the dog, but still. They made it. Most of them.

 

[Doug&Julie]

Not an MME, but this is worth a watch re: this thread....

 

[dtbaker61]

There’sa question: which battery is used for heating? I assumed it was the 12v. I thought the 400v was only used for driving.

the dc-dc converter pulls from 400+v HV battery to run all the 12v 'stuff' like lights, radio, computers, and yes, e-heat. All the 'normal' heating/cooling accessories are designed for 12v because that's pretty common and available from existing ICE stuff.

this is WHY the dc-dc converter has a big fat circuit for 160amps.... expecting all the 12v loads to be up around 2000 watts, for heating and cooling.

with another dc-dc, we could have another dedicated heat-pump for cabin heat, or to provide 'performance chilling' for the inverter for performance loads well beyond 5 seconds.

 

[dtbaker61]

Not an MME, but this is worth a watch re: this thread....

such bullshit.
if you are worried about getting stuck in a snowdrift, get a 12v electric blanket (100 watts), and your MME will keep you TOASTY for many more hours than a tankful of gas in an ICE and not poison you with CO.

 

[louibluey]

the dc-dc converter pulls from 400+v HV battery to run all the 12v 'stuff' like lights, radio, computers, and yes, e-heat. All the 'normal' heating/cooling accessories are designed for 12v because that's pretty common and available from existing ICE stuff.

this is WHY the dc-dc converter has a big fat circuit for 160amps.... expecting all the 12v loads to be up around 2000 watts, for heating and cooling.

with another dc-dc, we could have another dedicated heat-pump for cabin heat, or to provide 'performance chilling' for the inverter for performance loads well beyond 5 seconds.

Everything (pumps, diverter, blower, etc) is 12V, except for the heating element itself, which is high voltage. This is common (heating element running on hv) in EVs, PHEVs and BEVs.

 

[DaMeatMan]

People really blow stuff like this out of proportion. Let's get real about something, if your in an actual life threatening emergency situation, and your not taking measures to ration and make efficient use of resources on hand, and you decide to just crank that heat and sweat with jacket off then I guess natural selection will take care of the rest.

On the other hand... if you're a rational thinking human being, you will take stock of how much fuel you have (be that gas or electrons), and you will hopefully decide to use that precious resource sparingly in an emergency with survival in mind, with comfort taking a distant last place on the scale of emergency priorities. Which again is the SAME concern one would have no matter if it's gas or electricity powering your vehicle. People being people do not drive around with 100% full batteries, or 100% full fuel tanks, and you need to act accordingly in either case. I'm sure there are many people who get on the freeway each day with a yellow empty gas light staring right at them in the middle of the winter. So this is more of a human nature problem, rather than a technology problem based on what is powering your vehicle.

If your by yourself without passengers or kids in the back seat, you would be wise to just turn on your seat warmer which draws no more than a few hundred watts which will last you weeks not days in an electric vehicle. Because the high voltage pack just tops off the 12v battery which is running nothing but a few necessary accessories and your seat heater. Whereas in a gas car you need to run your engine or risk killing your 12v battery if doing the same thing.

If you got a bunch of kids in the back seat then you need to actually use cabin heat as well, but you can cycle the vehicle on and off, to warm the cabin a bit then turn off for an hour or so.

It is winter time and no one should be leaving the house without warm clothing and a winter jacket. Any reasonable human being should also have a few blankets and or spare warm clothing along with some water and a few snacks in the vehicle.

I think when it comes down to it, most of this comes down to basic common sense and basic preparedness no matter what type of vehicle you are in or what type of technology is powering it. But not everyone thinks that way. My wife for example will leave the house in the middle
of the winter in a fleece jacket because her winter jacket is "too puffy and uncomfortable and she's not going far", in which case I will simply look at her and ask "what if you get into an accident and need to be standing outside your vehicle in the cold?"? At which point she usually responds with, "your right maybe I should bring my jacket"... really?? You think?!

If people just use common sense and take just a bit of precautions, most of the dangers can be mitigated in this type of situation.

 

[ChasingCoral]

Everything (pumps, diverter, blower, etc) is 12V, except for the heating element itself, which is high voltage. This is common (heating element running on hv) in EVs, PHEVs and BEVs.

Thanks. It’s always good to see the facts once in a while on here.

 

[Sneezy]

The vast majority of drivers don't plan for "what ifs" on a trip. They leave the house in 20 degree temps with no blankets, water, bucket to pee or poop in, etc. No flashlight, no idea where their car jack is, don't keep the gas tank at least 1/4 full, ....

I95 is a nightmare to drive. In a major snowstorm, you should expect the worst. I assume that anyone with 4x4 simply drove down the shoulders if they could. Why the police didn't back people up the ramps and off I can't imagine.

That's my wife in her Prius. I gave up lecturing her but she at least keeps a blanket in her car when she travels to see her parents once a year.
We have had 2 close calls when we were young and had young kids. I swore to never do that again.

I have a friend who calls me every other year to bring him gas because his car ran out....in town....
Stupid.

 

[RickMachE]

That's my wife in her Prius. I gave up lecturing her but she at least keeps a blanket in her car when she travels to see her parents once a year.
We have had 2 close calls when we were young and had young kids. I swore to never do that again.

I have a friend who calls me every other year to bring him gas because his car ran out....in town....
Stupid.

Tip - don't bring it to him.

My son ran out of gas on our minivan close to home, turns out the gas gauge was bad. However, he also knew the number of miles he could drive on a tank, and was ignoring that despite me teach it to him.

Fast forward a week, and knowing the gauge is bad, and knowing that he should watch the mileage, he runs out again and calls. He's a few hundred yards from a gas station, so I advise him to walk over and get gas, paying for a can if he has to, and do it a few times. Of course he does it once, and then wonders why it doesn't start.

After that, I felt the fuel pump, in the tank, might be burning out from lack of gas so I replaced it and the sending unit for the gauge, and made him pay half.

Sometimes lessons are hard to teach.

 

[Awmustang]

Here's another take on the EV stuck for 12 hours issue. He even mentions the article that others here have mentioned. Again, not a Mach E but even if the Mach E were 50% less efficient than the Tesla, you should be able to make it through this ok, provided you had the sense to not run your battery too low. It's just like the old advice to not let your gas tank get too low in the winter.

 

[Kevin P]

I think when it comes down to it, most of this comes down to basic common sense and basic preparedness no matter what type of vehicle you are in or what type of technology is powering it. But not everyone thinks that way. My wife for example will leave the house in the middle
of the winter in a fleece jacket because her winter jacket is "too puffy and uncomfortable and she's not going far", in which case I will simply look at her and ask "what if you get into an accident and need to be standing outside your vehicle in the cold?"? At which point she usually responds with, "your right maybe I should bring my jacket"... really?? You think?!

If people just use common sense and take just a bit of precautions, most of the dangers can be mitigated in this type of situation.

My high-school age boys absolutely REFUSE to wear anything beyond a hooded sweatshirt on the bus-ride to and from school. I have always pictured them standing on the side of the road shivering and turning blue after an accident. Its only that I know one of us could quickly retrieve them that I haven't pushed the issue. I myself don't wear a heavy coat while driving (its generally not a good idea because the puffiness makes seatbelts less effective.) But I throw something in either the back seat or the trunk, and always have a knit hat available somewhere. Along with a bunch of other things

If the family is going any distance to speak of we have water, blankets, coats, etc in winter.

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