With a 20-mile (round trip) commute, you shouldn't need to charge every day. That said, cold weather
will degrade range, especially on short trips -- with a 10-mile drive, you'll probably use almost twice as much electricity as you would in warmer weather, so you might use 40 miles of rated range rather than the 20 miles you were expecting. That alone won't account for what you're seeing, though, unless you're getting nervous and charging when your range hits 150 miles or so. It's probably best to keep the battery's state of charge (SoC) between 20% and 80% (so, 50-200 rated miles, given the SR+'s official 250-mile rating) as much as possible, but that's 150 miles of practical range, which should get you to and from work three times, even with massive losses because of cold weather.
Vampire drain can be another issue. This is when the battery's state of charge (SoC) drops even when you're not driving. There are many settings in the Tesla's UI, and things you can do even when you're not in the Tesla, that can increase vampire drain. Some that spring to mind include:
- Cabin overheat protection -- This feature is supposed to keep the cabin temperature from rising too high in the summer. I don't recall offhand if it does anything in the winter; if it does, it might be sucking power at this time of year.
- Sentry Mode -- This feature consumes power to keep the computer and cameras running whenever it's in use. Most users report that it costs the equivalent of about one mile of range per hour of use, so if you leave it running 24/7, it'll cause significant range loss.
- Smart Summon standby -- I don't recall the exact name of this feature, but if you have a car with FSD, the Smart Summon feature has an option that leaves the car in a state that's supposed to make Smart Summon work more quickly. The trouble is that it does this by leaving the computer and cameras operating, which causes the same sort of vampire drain as Sentry Mode. Unfortunately, this option is enabled by default, so you may be seeing range loss because of it.
- Temperature preconditioning -- If you keep the heat/AC on unnecessarily, it can drain a lot of power. This shouldn't be a big deal if you simply turn on the heat five minutes before getting into the car, since if you didn't do this, the heat would still be blasting on high for the first few minutes of your drive, and you'd effectively be wasting whatever heat the car would produce in the last five minutes of the drive. OTOH, if you use Dog Mode for extended periods or turn on the heat long before you depart, you can consume a lot of electricity.
- High cabin temperatures -- If you set the cabin temperature high (say, 75 degrees F), you'll consume a lot more power than you would with a lower cabin temperature (say, 68 degrees F). (The opposite would be true in the summer, of course.) Using the seat heaters can help you feel comfortable even with a relatively low cabin temperature; the seat heaters use much less electricity than the cabin heater.
- Remote checks -- Whenever you check the car's status with its app, the car will "wake up" and go into a relatively high-power state. It then takes anywhere from a few minutes to a couple of hours to go to "sleep" again. Thus, to preserve battery life, you should open the Tesla app infrequently at most.
- High speeds and high acceleration -- These consume more power than driving more sedately. If you've been having fun by stomping on the accelerator, you may improve your range by being more restrained.
- Bad weather -- You have little control over this, but driving through rain, snow, and slush takes more power than it does to drive on dry roads. Likewise, extreme cold or heat increases the need for heating or AC. You might be able to plan some trips for times when the weather will be better, though -- if it's clear in the morning but the forecast is for rain in the afternoon, you could do your grocery shopping trip in the morning rather than wait.
There are probably other settings and practices that can help you, but these are the ones that spring immediately to mind.
Another point is that Superchargers are likely not your only charging option. Check
PlugShare to find Level 2 (J1772 and Tesla) charging options near you. These will be slow, but can help a little even if you'll be somewhere for a short time, and can add significant range if you'll be parked for a while (like if you go to see a movie). You might also want to look for CHAdeMO DC fast chargers; you can use these if you buy a
$450 adapter from Tesla. This adapter isn't worthwhile for most Tesla owners, but if you don't have at-home charging and if there are convenient CHAdeMO stations, it might be worth getting. Note that there's a PlugShare app, as well as a Web site, so you can load it on your phone and use it to locate charging near wherever you happen to be. The big charging networks also have their own apps, so you can get the apps for whatever networks are common in your area; but PlugShare will give you the "big picture."
