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Are seat heaters more efficient than AC Heat?

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I have a couple of long trips to the snow coming up. 2020 non-heatpump Model 3

Anyone have thoughts from an efficiency standpoint, of the use of seat heaters, instead of using the resistive heater via the climate control system?

Car will have 4 occupants, so the seat heaters would be activated x4
 
A seat heater has to heat a tiny area (you/your passengers butt and back), and it's very well insulated. Some perhaps more insulated than others ;-)

An air conditioner has to heat huge amounts of air. It's not great when you don't have an engine to steal heat from.

You're going to use both. But remember to keep it on recirc wherever possible.
 
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I would never have the ventilation off with four people in the car unless it’s some sort of make-or-break emergency. With HVAC off, you’re going to exceed several thousand ppm CO2 in the cabin very quickly. You will also have extreme moisture buildup and condensation on the insides of your windows. The same goes for running the system in recirculate mode.

But to answer your question, yes, seat heaters use less power than HVAC.

My recommendation, having personally had to minimize my consumption in order to make it to a far away destination without charging, is to run the climate control at the minimum temperature (60°F) and a manual fan speed of 1 or 2 and the system on fresh air. This will provide some ventilation to the occupants and keep your windows clear without using much heat. Use seat heaters to supplement the low cabin heat.
 
It doesn't matter because since V11 you can't have the heated seats on without the AC on.
Sure you can.

1.) a recent software updated added the ability to add the seat heater controls to the bottom of the screen

2.) if you don’t have the software update described above, you can turn the HVAC on, adjust your seat heaters, then turn it back off. The seat heaters will remain as you set them.

3.) you can control the seat heaters from the app without turning on HVAC.
 
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1.) a recent software updated added the ability to add the seat heater controls to the bottom of the screen

I discovered only a couple of days ago that all that extra space in the dock not used by customisable Apps is used by car controls - if you choose to add them. I used to think “what a waste of space… Tesla could fit 2 or 3 more Apps in the dock!”

I needed the seat heaters, so I long-pressed the customise icon, dragged the grey picture of the driver seat to the dock, thinking it would replace one of the Apps, but it didn’t. It added the two front seat icons into the space between the Apps and the temperature controls.

Voila! I can now easily turn seat heater on and off. And get rid of these icons again in the spring when I don’t need them (and don’t want to accidentally turn them on).
 
I would never have the ventilation off with four people in the car unless it’s some sort of make-or-break emergency. With HVAC off, you’re going to exceed several thousand ppm CO2 in the cabin very quickly. You will also have extreme moisture buildup and condensation on the insides of your windows. The same goes for running the system in recirculate mode.

Thanks. No it certainly wasn't my intention to have the HVAC off altogether, but rather, have it set to a fairly low temperature (maybe 18 degrees) so the heating element isn't needing to do much work. And then the seat heating would be used to take up the slack (along with fairly warm clothing)

We will be spending a few days at the ski resort and there is no destination charging, so I need to make it up and back to the superchargers. Approx 200 km, midwinter and about +1000m vertical elevation.
 
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Making it back to the supercharger will be easy, given you’ll be on regen for most of the trip back down.

But which ski fields are we talking about? If Thredbo/Perisher etc,

Yeah it's perisher, @ 1600m or so. We will be leaving perisher for the trip home very early AM. How effective is the regen from a cold start at -5C? I have not yet been in this situation.

add a little more charge at the NRMA 50kW chargers at Jindabyne on the way through, regardless of what you add at the Cooma Supercharger.

I will if the opportunity presents itself, but I've trained myself to not rely on the NRMA chargers on road trips! Admittedly this one is 2 stalls, but still...
 
Yeah it's perisher, @ 1600m or so. We will be leaving perisher for the trip home very early AM. How effective is the regen from a cold start at -5C? I have not yet been in this situation.
Folks take Teslas to Perisher all the time. It’s very doable. Just consider whether you really need sentry mode on all week. That’s the main cause of phantom drain in my experience (1/2020 SR+).

If leaving Sentry Mode off concerns you, are you certain there are no local charging opportunities? Admittedly only two of the lodges have PlugShare listings (Corroboree and The Man from Snowy River), and those are for guests only. Tradition is to support the businesses that support us, though that isn’t always possible, especially in high season. If there’s an opportunity to use the granny charger for a little while, ask.

But even on a cold day you’ll add a LOT of charge going downhill, and more importantly, your car doesn’t need to draw much from the battery when gravity can do the work. The real important bit is don’t charge too high when you’re there - even if you have the opportunity - otherwise you’ll lose too much regen opportunity on the way down.
I will if the opportunity presents itself, but I've trained myself to not rely on the NRMA chargers on road trips! Admittedly this one is 2 stalls, but still...
Check PlugShare when you’re at Cooma, and decide whether to charge above 90% for peace of mind based on what you see.

In Winter they’re heavily used, so there will be lots of check ins. Not everyone checks in if it works, but if they’re broken or heavily queueing, umm, you’ll know. Also tell PlugShare to send you an alert for ‘New review or photo’ and listen for phone alerts (on hands free, of course) as you drive, in case something changes.

You might have to wait for a free stall, given how many EVs are on the road nowadays, but that’s worth it for peace of mind.

Once you’re there, if you’re queueing, discuss the same sort of thing with other drivers.

* Don’t charge too much - 80% is plenty to get up & back
* Consider switching Sentry Mode off while you’re parked up there.
* Let gravity do most of the work coming back down, and get as much as you can into regen. Which is what you should be doing anyway.
* If all of the above completely fails, Jindy’s charger will still be there on your way back. Just check PlugShare if you want peace of mind.
* Tow trucks exist. Are you a fully paid up NRMA member?
* Cancellations will be a thing. People are known to cancel travel if they’re sick, especially nowadays. If you’re completely and utterly stuck, and everything is broken, consider calling other accommodations listed on PlugShare and ask if they have a room for the night and a power point.
 
Just consider whether you really need sentry mode on all week. That’s the main cause of phantom drain in my experience (1/2020 SR+).

Yes absolutely onboard with this recommendation. I definitely have no intention of using sentry mode for the stay. I rarely use it.

If leaving Sentry Mode off concerns you, are you certain there are no local charging opportunities? Admittedly only two of the lodges have PlugShare listings (Corroboree and The Man from Snowy River), and those are for guests only. Tradition is to support the businesses that support

Yes, positive. In fact, during winter there is no overnight parking allowed beyond Smiggins, with one exception "The Man" as you mentioned above. Ive actually stayed there a few times previously, but couldn't get in this year. They have an undercover carpark with Tesla destination chargers. Nice setup.
You might have to wait for a free stall, given how many EVs are on the road nowadays, but that’s worth it for peace of mind.

We'll be 4 up with the kids, so I'm really trying to avoid becoming reliant on the NRMA chargers, but will definitely take the opportunity if they are available and working.
 
Seat heaters use a lot less energy, even 4 of them. But I find them to be a distant second in comfort. The advantage is you can likely lower the cabin to say 60F and still be comfortable with the seat heaters. As others have mentioned with 4 people breathing you likely have a window fogging issue without running the main heat. If by chance your place has ANY 120V outlet available it greatly helps to add 50+ miles each night. I always carry my charger and a 25' good quality extension.
 
But even on a cold day you’ll add a LOT of charge going downhill, and more importantly, your car doesn’t need to draw much from the battery when gravity can do the work. The real important bit is don’t charge too high when you’re there - even if you have the opportunity - otherwise you’ll lose too much regen opportunity on the way down.

I have to disagree with this. Regen is severely limited or completely unavailable when the battery is cold. Don’t rely it reclaiming much energy, and definitely don’t pass up an opportunity to charge on the assumption that regen will get you enough to reach your destination. ABC: always be charging, especially in winter.
 
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I find the seat heaters obviate the need for cabin heating, but I am usually in Sydney, so like 9-10 Celsius overnight.
Haven't tried them in snow, assume people are right when they target low cabin temps with main heater and add butt warmth...
 
How effective is the regen from a cold start at -5C?
The battery has quite a lot of thermal mass, so it depends a lot on how long it's been sitting at -5C. It was -5C when I jumped into the car this morning, but the battery had only finished charging an hour or two beforehand, and the car had been preconditioning, so regen was fine.

Sitting unplugged in a carpark at Smiggins for a few days is a different matter. The battery will be very cold by then, and it won't matter too much whether you get an early start in the cold or a late start with the sun out for a few hours - it'll still be cold. Likely you'll see the snowflake, and your regen is sure to be quite limited.
 
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