Short trips are going to be your worst case scenario usually for efficiency.
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Super charging at -10F
- Thread starter JAMBergie
- Start date
The S and X can begin to limit regen around 50F and below, but having a dedicated pack heater they can better deal with colder temps. If the pack needs to warm a little for a given charge rate it can do so relatively quickly.
Far as efficiency, short trips are worst case because the heater is working hard to warm everything. With my S and it's dedicated pack heater I can triple my commute energy use per mile just by not preheating. Of course preheating uses that energy and likely more because the interior is heated longer.
On a longer drive though the interior temp stabilizes and is no longer such a dramatic drain.
Far as efficiency, short trips are worst case because the heater is working hard to warm everything. With my S and it's dedicated pack heater I can triple my commute energy use per mile just by not preheating. Of course preheating uses that energy and likely more because the interior is heated longer.
On a longer drive though the interior temp stabilizes and is no longer such a dramatic drain.
Yes. Short trips greatly increase consumption because you're warming the pack and cabin at the start of every trip. It's doing several short drives with an hour or two parked (not charging) in between that's how you get to see 5-600 Wh/mile sometimes.
Yes short trips are bad. Because it take a ton of electricity to get the cabin up to temp where heater is running full load. Also slow speeds and heater really increase Wh/mi. I’m in the same boat.
Wahbash
Member
I'm not talking about heater loss, I don't think. My car is in the garage at night, and I tell it to warm up to 70 while it is charging before I leave. When I unplug the car in the morning to leave for work, the inside is already toasty and my energy consumption (since last charge / since right now) is reading zero.
As soon as I drive out of the garage though, I start spending energy quite quickly, at about a rate of 2 miles of range for every mile traveled. So, in my five Mile drive to work, expending about 10 miles of power. I don't think that is cabin heater since the car is already warmed up.
I suppose I could test it though, and drive to work with the heater off, see what results I get? Is only 5 degrees out right now, should be fun haha!
Kant.Ing
Member
Wonder if a hill hold (if there is a hill) can heat up the pack quicker without damaging the motor. For the shared heating/cooling system, not sure how the algorithm prioritizes.
The vehicle hold function uses the iBooster to hold the brake calipers on, so it will have no direct effect on warming the vehicle.
Also I’ve figured out that if it’s plugged in and done charging when you pre heat it draws the energy from the battery not the line. So the sudden mile drop is probably correction for that battery loss used in pre heating. Also the battery mile meter is useless in the winter. Try switching to % and use the energy app to gauge range and Wh/mi? Also when you leave do you go up hill. Up hill is the largest energy drain. I go downhill to work and uphill back. It’s about 8 miles each way. There are times I use 1-2% (3-6 miles) there and 7-8% (21-24 miles) back.
How are you figuring it doesn't draw from the line? Anytime i've turned the heat on you an see it kick off drawing power from the outlet if the car is plugged in.
I believe what it does is the Heater is on the "DC" side of things. When Plugged in and Cabin Heat is on, power goes through the Inverter and straight to the Heater. Bypassing the Battery.
It's kind of like a PowerWall Setup. Where Wall Power in your car is like Solar Power in a Power Wall. When Solar is Producing and you present a load, Solar Power goes straight to the load. If no load, it can charge the battery. If no Solar Power the Load gets its power from the battery.
It's probably very similar switching/sensing tech. Except what's AC and DC in the two systems.
There's no switching involved in either of those scenarios. The battery is in parallel with the loads, and the electricity follows the path of least resistance.
this is still pulling power from the wall and coleAK is saying it doesn't from how I read his statement. IF your car is plugged in and you even just open the door and it kicks on climate it will start pulling from the wall, as it should.
Wahbash
Member
UPDATE. coleAK I owe you an apology
So I did my test this morning. Charged the car up for 30 minutes before I left for work, but shut off the climate control. I then left and drove to work with the climate shut off and no music, which was fun at zero degrees F this morning. Holy hell if that wasn't the most efficient run I have ever recorded, came in actually at 100.7% because I technically drove more miles than I used in battery range. My Wh/mi was only 212. I don't remember ever seeiing it below 350. I was stunned. I had no idea the heating system took so much power.
Sorry I doubted you.
Wish I could do that every morning but the problem is the windows all fog up and I can barely see a damn thing haha.
To answer your other question, no real hills between my house and work. It is pretty level, except for a rise over a railroad bridge.
So I did my test this morning. Charged the car up for 30 minutes before I left for work, but shut off the climate control. I then left and drove to work with the climate shut off and no music, which was fun at zero degrees F this morning. Holy hell if that wasn't the most efficient run I have ever recorded, came in actually at 100.7% because I technically drove more miles than I used in battery range. My Wh/mi was only 212. I don't remember ever seeiing it below 350. I was stunned. I had no idea the heating system took so much power.
Sorry I doubted you.
Wish I could do that every morning but the problem is the windows all fog up and I can barely see a damn thing haha.
To answer your other question, no real hills between my house and work. It is pretty level, except for a rise over a railroad bridge.
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It’s all good. Early on this winter I did some testing of my own. And was surprised as well. Makes sense though as electric heaters all draw a lot of power. I think the glass roof also dosnt help with containing heat. I’m thinking of trying to make quilted insulation panels like the Tesla sun shades.
Frozen windows aren’t an option so I’ll keep the heat on. Still better than 12 mpg in our LX570.
Jaywlker
Former Vendor
Ask was mentioned, if it’s below -20F “safety” heating then it would kick in heat as needed regardless of charging.
Not sure if that will automatically do a “shore power” method like it does for cabin heating when plugged in. Versus use the battery and not charge until it’s 5% below set limit. I would hope it does the former.
