Overnight in 0°F weather? Travel Tips?

[jcanoe]

Well, I had to read it a couple of times, and then I got what @jcanoe was saying, although it is stated in a way that is confusing and gives kind of a misleading impression.

Technically true, as far as just being physically plugged in not actively doing something, but definitely misleading, because....

...charging is always what's happening!! That's the reason why people are plugging into a lowly 120V outlet in really cold temperatures. People aren't using the scheduled charging to only have it wait until 2 AM or something to begin charging on a 120V outlet. It takes days to recharge, so whenever people are plugged into a regular outlet, they are drawing current for warming and charging.

I could have been clearer. If you normally charge to i.e. 80%, once that state of charge is reached the Tesla stops charging. At that point if the Tesla remains plugged in, whether on a 120V or 240V charging setup, the Tesla is no longer maintaining the temperature of the battery pack, the battery pack will cool down to ambient temperature.

Separately, when you are attempting to charge the Tesla in temperatures at or well below 32F (0C) using Level 1 charging (120V/12A, (1.44kW) the charging time will be much longer because the Tesla will have to balance warming the battery pack (drawing up to 7.2kW) and charging at the maximum 1.44kW. If it is cold enough you won't be able to effectively charge the battery using Level 1 charging because all of the 1.44kW available power being put into the battery will be consumed to keep the battery at a temperature where charging can take place. You could charge for more than 24 hours and the result would be very little additional charge added to the battery. In extreme cold having access to Level 2 (240V) charging is, for practical purposes, required.

 

[bchan911]

While I cannot speak to all the technical mumbo jumbo, I can say from real world experience since I exclusively charge my car via regular 120V outlets...

With temperatures around zero to -5C in a underground garage...

• Able to achieve +7km/hr
• Average +17% battery in a 12hr shift
• Battery is semi-warm (when I cold start the car, regen is reduced...only about 1/5 available)
• Interior temperatures while charging stays approx. 7C (as opposed to the colder outside temps)
• Sentry Mode off, summon off

Turning on driver seat heater to medium and having HVAC set to auto @19C

• Able to charge +1km/hr

Hope this gives you some insight into the mobile charger in colder temperatures. Its actually more effective than advertised, and for my typical short city driving trips, it's highly effective and FREE!

 

[jcanoe]

While I cannot speak to all the technical mumbo jumbo, I can say from real world experience since I exclusively charge my car via regular 120V outlets...

With temperatures around zero to -5C in a underground garage...

• Able to achieve +7km/hr
• Average +17% battery in a 12hr shift
• Battery is semi-warm (when I cold start the car, regen is reduced...only about 1/5 available)
• Interior temperatures while charging stays approx. 7C (as opposed to the colder outside temps)
• Sentry Mode off, summon off

Turning on driver seat heater to medium and having HVAC set to auto @19C

• Able to charge +1km/hr

Hope this gives you some insight into the mobile charger in colder temperatures. Its actually more effective than advertised, and for my typical short city driving trips, it's highly effective and FREE!

Thank you for your example charging using 120V in colder temperatures. When you arrived at work the Tesla's battery pack was already warm. The second example, setting the HVAC to Auto and 19C resulted in adding 1km/hr is similar to what would happen if you were charging at 120V starting with a cold battery pack.

 

[mk677]

Hello! I'm planning a very short road trip and I thought I'd cover my bases about overnight vampire drain and any other tips! I'm in Minnesota. It will be cold and a chance for light snow on the way there. I know to set my depart time while plugged in to precondition.

My trip is only 130 miles each way. There is a supercharger 15ish miles away from the resort.

It will be sub zero temperatures at night and I'm staying 2 nights (might drive a few times to grab a bite to eat). During the day it will be 5-20°F

If I arrive at the resort with 70% (ish) after supercharging before I get there, how much charge am I expected to lose over a 48 hour period? (I don't have sentry or summon)

it depends on what apps you have installed and how you configured the car.
if you could find an outlet, even 110, it would be good to keep the car plugged in
and disable any 3rd party apps that you may have installed

 

[bchan911]

Thank you for your example charging using 120V in colder temperatures. When you arrived at work the Tesla's battery pack was already warm.

• My commute to work is typically less than 10minutes travelling <40km/hr. (In the summer I usually skateboard, but it's too cold right now )
• Lately the temperature has been like -7C feeling like -15C with the wind chill.
• I don't pre-heat the battery because (a) I don't have a plug at home, and (b) waste of battery for me.
• Battery is still frozen (with snowflake sometimes) with only a dot or no regen available at all when I get to work
• So I would say my battery is COLD when I get to work
• The underground garage at work is obviously a little warmer than outside temps, but not by much, usually the temp gauge on the car typically reads around 0C if not slightly below
• I can typically get the +7km/hr charging speeds immediately if not within the hour once the battery pack warms up a little

The second example, setting the HVAC to Auto and 19C resulted in adding 1km/hr is similar to what would happen if you were charging at 120V starting with a cold battery pack.

• Sorry let me clarify, I noticed a couple of times that my car only charged 3-10% after my 12hr shift.
• I ended up finding out that some of the 120V plugs at the underground garage had poor wiring and was only generating 9/12A
• During my break, I drove around the parking garage and tested some of the outlets
• In testing, noticed that I would only get +1km/hr if I was in the car with the seat warmer and HVAC on
• The moment I turned off the HVAC but kept the seat warmer on, it jumped back up to +7km/hr
• This was done after driving a COLD battery/car only 10 minutes to work (as mentioned above), and parked unplugged for 1.5hrs before I was able to find a free plug that had better wiring. So essentially a COLD battery
• I was hoping this would give you an idea of how much power you'd lose/gain if you chose to pre-warm your car
• Unfortunately I don't usually have any connection to my car cause it's always parked underground in concrete so I can't tell you what kind of charging speeds I would get if the car is pre-warming prior to departure

Hope this helps! Cheers!

 

[jcanoe]

• My commute to work is typically less than 10minutes travelling <40km/hr. (In the summer I usually skateboard, but it's too cold right now )
• Lately the temperature has been like -7C feeling like -15C with the wind chill.
• I don't pre-heat the battery because (a) I don't have a plug at home, and (b) waste of battery for me.
• Battery is still frozen (with snowflake sometimes) with only a dot or no regen available at all when I get to work
• So I would say my battery is COLD when I get to work
• The underground garage at work is obviously a little warmer than outside temps, but not by much, usually the temp gauge on the car typically reads around 0C if not slightly below
• I can typically get the +7km/hr charging speeds immediately if not within the hour once the battery pack warms up a little

• Sorry let me clarify, I noticed a couple of times that my car only charged 3-10% after my 12hr shift.
• I ended up finding out that some of the 120V plugs at the underground garage had poor wiring and was only generating 9/12A
• During my break, I drove around the parking garage and tested some of the outlets
• In testing, noticed that I would only get +1km/hr if I was in the car with the seat warmer and HVAC on
• The moment I turned off the HVAC but kept the seat warmer on, it jumped back up to +7km/hr
• This was done after driving a COLD battery/car only 10 minutes to work (as mentioned above), and parked unplugged for 1.5hrs before I was able to find a free plug that had better wiring. So essentially a COLD battery
• I was hoping this would give you an idea of how much power you'd lose/gain if you chose to pre-warm your car
• Unfortunately I don't usually have any connection to my car cause it's always parked underground in concrete so I can't tell you what kind of charging speeds I would get if the car is pre-warming prior to departure

Hope this helps! Cheers!

Thank you, it definitely helps to know that charging at 120V is possible with a cold battery pack in temperatures as low as -7C (19F)

 

[mk677]

Thank you, it definitely helps to know that charging at 120V is possible with a cold battery pack in temperatures as low as -7C (19F)

just be aware that 120 charging is not going to add much range, 1-3 miles per hour

 

[jcanoe]

just be aware that 120 charging is not going to add much range, 1-3 miles per hour

In moderate temperatures it has been my experience that charging at 120V/8A is good for 3 to 4 miles of range added per hour; at 120V/12A yields 4 to 5 miles of range per hour. I do believe that if it is cold enough and you start with a cold battery pack that charging for 8 hours will not result in many miles of EV range added as most of the available power from the 120V receptacle (~1kW to ~1.4kW) will go to heating the battery and keeping the battery warm.