Energy usage by function

[ttdanimal]

This is probably answere somewhere but couldn't find.

Generally, how much energy is used by the various functions in the car?

- heat
- radio
- dash cams
- seat heater
- amient lights
- screen
- etc...

I know there are many factors. But curious how to get a better idea so can make decisions when really trying to extend range. Especially in winter when range is significantly decreased.

 

[mswlogo]

Good idea Add it to MoreTesla.com verify with a few searches that's not already on the list and if so give it a thumbs up.

Personally, I'd be thrilled with HVAC and Seat Heaters. The rest is in the noise and fairly (constant) any way (are you gonna shut off the screen if it's more than you like )

 

[doghousePVD]

Heat is the big drain - seats, air, defrost, and steering wheel. All on is something like 6kw. All the rest are small, and not really controllable anyway.

 

[Fruitandfibre]

Aside from completely turning off the heater, is there a better suggestion than turning fan speed to 1 and temp to 65 to save on energy?

 

[doghousePVD]

Aside from completely turning off the heater, is there a better suggestion than turning fan speed to 1 and temp to 65 to save on energy?

Turn temperature to 60˚F and seats to low. Fan speed makes very little difference. Or wear a sweater.

 

[mswlogo]

Aside from completely turning off the heater, is there a better suggestion than turning fan speed to 1 and temp to 65 to save on energy?

Setting fan to low is counter productive. You may never reach the temperature you set if too low. Poor circulation can lead to fogging in in some spots forcing you to run defroster etc. The heating element is running regardless, might as well push the warm air to you.

You can be smart with HVAC but don't be silly.

In summer running too low can cause too much moisture to stay in the ducts and cause problems.

 

[AlanSubie4Life]

You can measure most of these items fairly accurately pre AC-DC conversion loss with judicious use of the car EVSE. Using 120V for smaller items with better resolution and 11kW at 240V charging for larger items and observing screen in a non charging state (threshold below current charge level).

Seat heaters are 50-100W.
Heat is at least 7kW when operating open loop.
Screen is around 100W
misc stuff and overhead is about 250W

All rough numbers; measure them if you want to determine them.

 

[mswlogo]

You can measure most of these items fairly accurately pre AC-DC conversion loss with judicious use of the car EVSE. Using 120V for smaller items with better resolution and 11kW at 240V charging for larger items and observing screen in a non charging state (threshold below current charge level).

Seat heaters are 50-100W.
Heat is at least 7kW when operating open loop.
Screen is around 100W
misc stuff and overhead is about 250W

All rough numbers; measure them if you want to determine them.

I think his whole point is it would be nice to know these numbers in practice, over time, in what you actually use. Not the peak load of the devices.

Be cool to have a breakdown of trip computer wh/mi of what was heat, seat, drive, ac

300 wh/mi Total 3000 miles
220 wh/mi Drive
40 wh/mi Heat
10 wh/mi Seat
10 wh/mi AC
20 wh/mi Misc ("always on" stuff)
-40 wh/mi Regen

etc.

 

[AlanSubie4Life]

I think his whole point is it would be nice to know these numbers in practice, over time, in what you actually use. Not the peak load of the devices.

Be cool to have a breakdown of trip computer wh/mi of what was heat, seat, drive, ac

300 wh/mi Total 3000 miles
220 wh/mi Drive
40 wh/mi Heat
10 wh/mi Seat
10 wh/mi AC
20 wh/mi Misc ("always on" stuff)
-40 wh/mi Regen

etc.

Yeah it would be nice to see it broken out. Would result in a lot fewer questions! Just important to realize that the faster you go the lower all of the accessory values get, so watts is important.

Seat heater is probably 1Wh/mi or so at 80mph.

 

[jjrandorin]

Yeah it would be nice to see it broken out. Would result in a lot fewer questions! Just important to realize that the faster you go the lower all of the accessory values get.

Seat heater is probably 1Wh/mi or so at 80mph.

I dont think it would result in any fewer questions. There would be the same amount of questions, just the nature of the questions would change. Instead of "whats using all my power?!?!?!?" It would be "Why does XXXX use so much power?!?!?! WTF was tesla THINKING? They should be able to make this more effficient, so why dont they????"

Or

"What exactly does the AC using 10 Wh/Mi mean?" what does this mean for my range? Is this why I have lost 7 miles range in the 4 months I bought the car???"

Thats what the questions would look like, and there would not be any fewer of them

 

[doghousePVD]

Things like heat are near meaningless measured in Wh/mile. How hot and how fast are you traveling. Hi speed travel in really cold weather will lose much more heat from wind blowing over windshield etc. so outside temperature really matters. Defrosting glass varies a lot on precipitation.

This stuff will just bring up more inane M3 comments and arguments.

 

[StealthP3D]

Turn temperature to 60˚F and seats to low. Fan speed makes very little difference. Or wear a sweater.

I disagree. The fan speed makes a big difference because a higher fan speed causes the cabin heater element to draw a LOT more current to produce air at the same temperature. You are effectively passing a lot more air through the cabin and all of it needs to be heated.

The seat heaters draw very little energy. On a medium setting, they get toasty warm and probably draw about 30-35 watts/seat (which is almost nothing in the grand scheme of things). If the air is dry enough that you don't have to worry about windows fogging, you can save quite a bit of energy in really cold weather by making sure the cabin air is set to "Recirculate".