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Winter charging issues, frozen charge ports, road trips
- Thread starter glhs272
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AlanSubie4Life
Efficiency Obsessed Member
Not exactly. On an energy conversion to work basis, Tesla probably does better (electric heat pump is probably more efficient than turning a combustion engine (which generates heat which heats the cabin) which in turn runs a pump to cool the cabin). Maybe a factor of 2 better. That is in absolute energy conversion terms.
However, on an available energy basis, most ICE cars carry perhaps 10x as much energy as an electric car (depends on which Model 3 you have). (33.7kWh * 15 gallons is 505kWh, nearly 10x an SR+)
So in terms of impact to your energy store, an EV with AC probably is about 5x worse than an ICE car, on a % basis.
So on a % of range basis, using the AC probably is about 5 times worse in an EV vs. an ICE. So if in an ICE it hurts your range by 2%, it might hurt your range by 10% in an electric car. These are just ballpark numbers - I don't know exactly what the numbers would be as it obviously depends on efficiency, cabin volume, heating load, vehicles being compared, etc.
Similar concept: using the AC in a vehicle getting 40mpg baseline has a much larger impact on range on a % basis than using it in a Lexus GX which gets 17mpg baseline.
This is why the Taycan is going to be so great. Lol.
Heat & AC use will have much less impact on its range than for an SR+, since the battery is twice as large. For consumption, it's just your static load (say 4kW for heating) divided by your speed (say 60mph): 4kW/60mph = 66Wh/mi
That's the adder. At higher speeds the adder will go down. So as you say, at lower winter speeds using that heat really hurts. There may be slightly more convective/conducted heat losses due to higher speeds, but wouldn't think it would be much of an effect unless there is a draft somehow.
I think you're underestimating the inefficiency of consumption engines. Let's take your example of 505kWh total. That's not accounting for the thermal efficiency of an engine. Numbers I've seen quoted seem to be 20-35% efficient. Let's assume it's ~33% since it makes my math easier... that leaves ~166kWh of actual motive power that gets from the gas into actually turning the crankshaft. Assuming the Tesla AC compressor and the gasoline belt driven one are equal in efficiency (which, I'm going to guess the Tesla one is better... but let's say it's not), then the AC penalty is probably a lot closer to 2x. And that's a lot of good assumptions for an ICE car. I think anecdotally we know that an ICE car doesn't really suffer much penalty from using the AC, so a Tesla isn't going to be that much worse for the AC only case.
Obviously, anecdotally, it's worse than ICE cars, but not THAT much worse (and frankly, I wonder if most of this is because folks hyper-focus on range and Wh/mi in Teslas... how often did we do that in the ICE days?).
Heat consumption is definitely not static and an adder regardless of speed/weather. It's a static adder until the car heats up the inside cabin, but then it tries to maintain your set temperature and the consumption drops off. How much it drops off is a factor of how cold it is outside as well as how fast you're going (and, whether you're getting rained on/snowed on). Faster or more rain/snow will leech more heat out of the cabin, therefore increasing the heat needed to keep everything cool. Anecdotally, this gets MUCH worse the faster you go in the rain when it's cold outside. I've had similar to OP's consumption (350-400Wh/mi) when I was driving ~75mph in 35F weather. This was on a long drive (~7 hours) so the initial static consumption was not a factor, but the cold and rain was. My normal consumption at 75mph seems to be around 260-280Wh/mi.
AlanSubie4Life
Efficiency Obsessed Member
Sure. I guess I should have used the word steady-state. But 4kW is not a bad steady state number to use for cold conditions. It ends up being about 2kW for a ~30 degree temperature differential (pretty easy to measure (after correcting for charging losses) if you leave a car preheating for a long time at a ChargePoint - which is what I did).
But once you know what the steady-state is, you can use the kW / velocity formula. Or vice versa to calculate wattage. Certainly convective/conducted heat losses that vary with speed will have a separate effect on the steady-state number (but I would say they're likely smaller than the effect of velocity - I doubt it takes anywhere near as much as twice the power to keep a car at a fixed temperature at twice the speed).
Sure. Could be 3x as much energy for that. I guess I thought maybe since the motor has to turn already for moving the vehicle there might be some gain but maybe not.
In any case yes that would make it more like a 10/3 = 3.33x impact vs. an ICE rather than 5x. As I said these are rough numbers. My main point was the enormous amount of energy available makes an ICE less sensitive to additional work (like cooling) that is required. But obviously the fundamental efficiency of doing work is really important and the worse it is the more impact AC would have.
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GPinzone
Member
I'm trying DeoxIT DN5 on my charge port to see if it will help prevent the locking pin from sticking in cold weather. I don't have enough data to say whether it makes a difference yet.
I've had my LR RWD since May, and have loved every minute of it.
This past weekend, I went for a quick trip that's about 160 miles away, and normally use around 150 miles of range to get there.
Used up 220 in 30 degree weather.
No good destination chargers, so I trickle charged overnight.
Hit a 120 kw Supercharger on the way home, conditioning the battery on the way. Three other cars, none near me, only got 55 kw charging.
Tried another plug, got the same.
Stayed about twice as long as I wanted to, then moved on, knowing I'd need another charge before my next destination.
Stopped later in a mall, 150 mhz...unfortunately it was packed, had to wait for a bay, then got another 60 kw speed.
Ugh.
Certainly doesn't change my thoughts about my car, but a frustrating weekend all around.
I was expecting less range in the cold, but this was more than I thought.
And I've been really frustrated with SCs in general. I got almost maximum speed the first few times I used one, but lately I haven't gotten close to cracking 80 or 90. That mostly in warmer weather as well. And yes, I know I would have done better at the mall if I wasn't plugged in next to someone.
Anyway, had to get that out of my system. Rant over.
Back to Tesla love, and looking forward to the next update.
This past weekend, I went for a quick trip that's about 160 miles away, and normally use around 150 miles of range to get there.
Used up 220 in 30 degree weather.
No good destination chargers, so I trickle charged overnight.
Hit a 120 kw Supercharger on the way home, conditioning the battery on the way. Three other cars, none near me, only got 55 kw charging.
Tried another plug, got the same.
Stayed about twice as long as I wanted to, then moved on, knowing I'd need another charge before my next destination.
Stopped later in a mall, 150 mhz...unfortunately it was packed, had to wait for a bay, then got another 60 kw speed.
Ugh.
Certainly doesn't change my thoughts about my car, but a frustrating weekend all around.
I was expecting less range in the cold, but this was more than I thought.
And I've been really frustrated with SCs in general. I got almost maximum speed the first few times I used one, but lately I haven't gotten close to cracking 80 or 90. That mostly in warmer weather as well. And yes, I know I would have done better at the mall if I wasn't plugged in next to someone.
Anyway, had to get that out of my system. Rant over.
Back to Tesla love, and looking forward to the next update.
Your experience is the reason they created V3 superchargers. Once the area has enough Tesla’s the V3 will be necessary.
right now, if you plug in next to someone, 60-70kW is all you can expect. Also, I’m sure you are aware, but peak charging rates only occur when the battery is at low SoC. Not sure what SoC you were at.
also, what is 150 mhz? Did you mean kW?
right now, if you plug in next to someone, 60-70kW is all you can expect. Also, I’m sure you are aware, but peak charging rates only occur when the battery is at low SoC. Not sure what SoC you were at.
also, what is 150 mhz? Did you mean kW?
The first real hit of cold weather can be a rude awakening for some. It really does have a noticeable affect on the battery. But you learn quickly what to expect in terms of winter range. The slow supercharger speeds are also unfortunate. Hopefully they continue to make improvements to the existing V2 superchargers.
V3 Superchargers won’t help when they start capping your battery.
If the pack was warm you’d see typical charge rates. The issue was most likely how poor the motor is at heating the battery while the vehicle is moving at high speed in cold weather. It warms the motor itself in an attempt to dump heat into the coolant loop that circulates through the battery. This warms the entire drive unit, and a good portion of its heat is shed to the environment before it gets dumped into the coolant. The higher the speed, and lower the temperature, the more severe this is. It’s SLOW to warm the pack with a single motor at highway speed, several hours to hit peak temp, and it may never if it’s cold enough outside. 30F isn’t that cold, but it certainly shows the downside of this design. The dual motor is a bit better since at least it has twice the motors to roughly double the heating. It still heats faster when stopped.
boriszima
Member
I guess thats why you usually do not hear this from owners who live in warmer climates compared to where true winter arrives.
I get stuck frequently here in the warm Florida weather with both Supercharger and mobile connector. I'll press the button on the handle and the light will light up blue but when I pull the handle the lock re-engages and the light starts flashing green. I use the phone to re-lock the car and unlock again and then it will turn blue again allowing me to remove the charging cable. I'd say this happens about 50% of the time I charge.
RFernatt
Solar/EV Owner/Enthusiast
Was driving back last night from visiting family in central West Virginia and decided to run an efficiency test in my LR AWD Model 3. So, sharing results if you have similar cold, mountain driving planned.
The setup:
The setup:
- Drove for a couple hours before stopping to charge, so car and battery were warmed up.
- Stock 19" wheels and tires at 42psi.
- Temps ranged from 28 - 32 degrees F, but usually below freezing.
- All night time driving, but no precipitation and wind was light.
- HVAC was set to 64 degrees and no other heat was used.
- AP was used most of the way.
- Trip was non stop averaging 70 mph (speed limit) across I68, I70, and I81 between the Morgantown, WV Supercharger and the Martinsburg, WV Supercharger.
- Left Morgantown with 82% charge level after charging from 13% from the previous 2 hour drive.
RFernatt
Solar/EV Owner/Enthusiast
Nope. Was wearing a heavy sweatshirt over my regular shirt and jeans. I typically run a little warm, so I don't mind it being on the cool side. If my wife had been in the car, I couldn't have gotten away with that.
YMMV in these types of conditions, but plan accordingly.
And I'll add that bit of info: driver only, no passengers and no cargo load but an overnight bag.
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Neither temperature outside nor in your garage matter. It's the temperature of the battery that matters.
It's a tremendous thermal mass, because it's heavy.
If you park outside and the battery drops below 0 degrees, and you come home with that cold battery and park it in your garage, it can take MANY hours for it to warm up to 13.
When you get moving with an ice-cold battery, it does not manage to warm up quickly from the driving, especially at high speeds in cold weather. If you drive on local roads, it heats up a little better - more acceleration /deceleration, and less cold wind blowing.
But it's all about the battery temperature.
Do you remember what trip planner arrival predicted? Just curious how accurate it was. I think those numbers are quite good especially given elevation and an approx 40wh/mi addition due to hvac.
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