First off: The motor and all in a Tesla work just fine at -40F. They test the vehicles up in Alaska.
Second: Modern Teslas come with a heat pump. This helps two ways:
- Extracts heat from outside cold air to heat the cabin. (There's a lot of heat needed in the cabin so people got toasty toes.)
- Extracts heat from outside cold air to heat the batteries/motors.
A Tesla will use waste heat (i.e., copper getting warm from the current; batteries getting warm from current flowing through them) to heat the batteries, motors, and to some extent, the cabin. There is an optimal temperature for all that stuff.
I used to have a 2018 M3 that had no heat pump. In warm weather, the car got 250 W-hr/mile; in cold weather, it got 350 W-hr/mile, that extra 100 W-hr/mile being used to heat the cabin with. The SO has a 2021 MY that, in warm weather, would get 280 W-hr/mile. In cold weather, as soon as one turned it on, it would do 350 W-hr/mile, then warm up, and the energy used would drop down to 290-300 W-hr/mile.
Yeah, and the seats are electrically heated, as is the steering wheel, with the intent that it's kind of cheaper to keep the cabin cooler and get warm from the seat.
The
real problem with a Tesla in the winter is charging it. Say it's -20F in your garage. The battery has to get warmed up somewhat to charge it, and the heater for the battery uses around 2.5 to 3.0 kW.
Thing is, if you use a 120 VAC, 15A socket (standard wall socket), the car will draw a maximum of 12A (NEC code says one has to derate 20% on a constant, heavy load, and, yep, that's a Tesla), for 120VAC x 12A = 1440W. So, right there, that means trying to charge a cold Tesla in the dead of winter from a 120 VAC wall socket kinda ain't a-gonna work.
If you're in the burbs and:
- Your breaker box has a pair of extra slots so you can put in a duplex breaker
- Your breaker box has, best case, 60A of extra capacity (an electrician will run something called a "load analysis" to determine that this is, in fact, the case).
- Worst case, you've got 30 A of extra capacity
Then, you're in business. A duplex breaker gives you 240 VAC. (You'll see this in your breaker box. A double, ganged breaker is, in fact, a 240 VAC breaker. You'll usually have at least one for your HVAC system.) If you've got a 30A circuit, then you can get 240 VAC @ 24A, that's 5760W, and more than enough to both get the battery warmed up and get the car charged. (Once the battery's warm, the current to do the warming part decreases dramatically.)
If you can put in a 60A breaker, then the charging power is 240VAC * 48A = 11.52 kW, which is the max current a Tesla can do. And there won't be an issue with getting the battery warmed up, either.
Generally, putting a Wall Connector (that's a box that can handle 240 VAC, the necessary current, and has a cable on it that fits into the car) on your abode somewhere.If you've got a garage,
in the garage is the best place to put this thing, although most of the Wall Connectors I've heard of are rated to handle being mounted on the outside of a house.
The Tesla Wall Connector can be bought from places like Walmart as well as Tesla, and there's third parties that'll be happy to sell you a non-Tesla one, too. A Wall Connector is Not A Charger. The Charger is actually in the car. The Wall Connector tells the car how much voltage/current is available (has a small computer in there for that) and a Great Big Contactor that goes "clunk" when, and only when, it's safe to apply voltage to the car.
Here's why it's cheaper. The Wall Connector costs $475 (or a bit less from some third parties). A
mobile connector is this cable-looking thing that, on one end, plugs into the car, and, on the other end, has one of a number of adapters that fits a 120/240/what-have-you socket, with lots of different ones for different current/shapes/what-have-you. See the
chart over at Wikipedia. The Mobile Connector costs around $250.
So, say one puts in a 50A breaker, 50A wire, and an
industrial grade, not from Home Depot, NEMA14-50 socket. The cheapies don't last. The ones that aren't cheap cost north of $200.
Then, on top of that, to meet code, you'll need a 240 VAC GFI breaker. That's another couple hundred bucks and, suddenly, the hard-wired Wall Connector is
cheaper. And can do more current.
Total cost for the electrical installation, including Wall Connectors and what-all, is around $1000-$1500 for a simple installation. If the electrician has to bust through brick walls, then, natch, the price goes up. Many enlightened states (NJ is one, dunno about IL) will subsidize charging infrastructure, up to and including getting a higher-power drop from the power pole in the street. Check your state's web sites.
Other than that: Teslas are cool in the snow.
Oh, yeah: In the cold, a Supercharger can't be beat. The lowest power Supercharger delivers 75 kW; the older Superchargers out there do 150 kW; and the modern ones being installed these days do 250 kW.
But, generally, Superchargers are for trips. Mostly, the cost per kW-hr on a Supercharger is 3X the cost of home electricity. (I get $0.18/kW-hr at home; the local stations are around $0.48/kW-hr, cheaper at night.)
If you check the numbers, running a Tesla around the landscape is about 1/3 to 1/5 the cost of an ICE vehicle, but only if you're using residential rates.
Minor caveat: The "Performance" versions of the Teslas (M3P, MYP, MS Plaid, etc.) come with something close to racing tires which are graded for summer use. Those tires don't work well below 40F or so. (But that's true of
any summer tire.) The non-P types (Standard Range and Long Range) come with All Seasons, which, mostly, will do a decent job in the snow. If you're the kind of person who likes snow tires, then knock yourself out, those have better traction in the snow. There are people with "P" cars that run Summers in the warm months and swap wheels to snows in the cold months. Me, I got LR cars over here, it's the mid-Atlantic, so I stick with All Seasons.
That 40% number you cited has nothing to do with Teslas. What it kind of sounds like is what happens to a standard lead-acid car battery, used for starting an internal combustion engine, in the cold. Hm. There were some non-Tesla BEV (Battery Electric Vehicles), I think the early Nissan Leafs were one, that didn't have built-in heating arrangements for the traction battery. So those cars might be an issue in the cold, but I've never owned one.
Hope this helps.
