Experimenting with heat and defrost effect on energy consumption

[Halodde]

Since I woke up to snow on the ground for the first time this morning, I decided to experiment with the climate and defrost functions so I could use the information for future planning. For reference, I park outside and will all winter unfortunately. I also live outside of Buffalo so we will have more than our share of cold and snow over the next several months. I unplugged the car yesterday morning and this morning, it was at 79% with an outside temp in the low 30's and interior temp reported by the app at 31 degrees. So, I turned on the climate to warm the car to 67 degrees and also turned on the defroster. When the app notified me that the climate control and defrost had shut off after 45 minutes, the interior temp was at 67 degrees and it had used 5% of the battery down to 74%. There was still some snow on the windows, roof and a little on the windshield so I decided to see if there was a noticeable difference in energy usage between using the heater vs the defrost functions. Presently running the defrost only and after a half hour, the battery is down to 71%. And the interior temp has risen to 85 degrees. My initial thoughts are that the defrost uses a significant amount of energy but serves to defrost AND heat up the interior. So, I will still have to try the heater alone on a cold morning to see how much difference there is when just heating the interior.

Has anyone else played around with this? I'd love to hear your experiences. BTW, the experiment was motivated by the fact that I will be spending multiple nights parked outside at hotels during the winter months. And, if I am not able to be plugged in, I wanted to know how much energy I'd lose by warming/defrosting the car in the morning so I could plan my travel/mileage better.

 

[joec]

I rarely set my temp higher than 72. I find the seat heaters and steering wheel heat keep me warm enough and use less power. But I tend to be comfortable at lower temperatures than a lot of people. And I hate having hot air blowing on my face.

I've never tried setting the climate and leaving it on while the car is not moving for 45 minutes. Doesn't surprise me you'd lose that much battery doing that.

What I have noticed is that I tend to get lower efficiency in winter in general. Snow tires, the friction caused by snow or rain, cold battery, the increased use of climate controls—I imagine these all contribute. But my feeling has always been that climate control is doing less to hurt efficiency than all the others.

 

[Adnillien]

When comparing the two scenarios, the battery is probably also being warmed when you first turned on the heat and defrost. It would then use less energy to keep the battery warm than to warm it up.

 

[Halodde]

I rarely set my temp higher than 72. I find the seat heaters and steering wheel heat keep me warm enough and use less power. But I tend to be comfortable at lower temperatures than a lot of people. And I hate having hot air blowing on my face.

I've never tried setting the climate and leaving it on while the car is not moving for 45 minutes. Doesn't surprise me you'd lose that much battery doing that.

What I have noticed is that I tend to get lower efficiency in winter in general. Snow tires, the friction caused by snow or rain, cold battery, the increased use of climate controls—I imagine these all contribute. But my feeling has always been that climate control is doing less to hurt efficiency than all the others.

I don't set my temp over 68 usually when driving. And, to clarify, the temp was set at 67 this morning for the experiment. But, running the defroster actually raised the temp well above the set temperature when I ran it by itself. And, of course, I normally wouldn't run either the climate or defrost that long either. It was just an experiment to assess the energy loss to figure out how much energy loss I would have when using it when I'm staying in hotels during the winter.