Doug_G
Lead Moderator
It used to be possible for the car to lose range while charging on 110V in extreme cold. A firmware update a couple of years ago prevents that from happening.
A cold soaked battery pack at -20C will, in my experience, not gain any charge on a 110V 15A circuit. Probably won't on a 20A circuit either, but I've not tried it. It will help a lot if temperatures warm up during the day. It will also help if you can keep the car out of the wind, which will otherwise drain heat from the battery pack very efficiently.
Good luck - I'm interested to hear what happens with your experiment...
A cold soaked battery pack at -20C will, in my experience, not gain any charge on a 110V 15A circuit. Probably won't on a 20A circuit either, but I've not tried it. It will help a lot if temperatures warm up during the day. It will also help if you can keep the car out of the wind, which will otherwise drain heat from the battery pack very efficiently.
Good luck - I'm interested to hear what happens with your experiment...
Needs insulation on the bottom of the battery pack. Surprised no one has tried this yet. Measured 75F on the bottom of the pack after driving around in 35F weather with max battery power heating on.
green1
Active Member
Starting warm from driving seems to be the real trick. My charge rate overnight dropped to 8km/hr instead of the 9km/hr I stated at, but I'm up to over 290km range now so I'm confident I'll get home. Temperature has also climbed to a positively balmy -10c. Parking indoors or out of the wind were simply not options, but there isn't much wind today.
This is a location I visit a half dozen times a year or more, installing a plug isn't really an option, however I have access to 2 20a 110v outlets on opposite phases so I'm trying to build a "quick 240" adapter to combine them, unfortunately I suspect the safety cutoff I put in there is causing the car to hate it, so I need to reevaluate.
This is a location I visit a half dozen times a year or more, installing a plug isn't really an option, however I have access to 2 20a 110v outlets on opposite phases so I'm trying to build a "quick 240" adapter to combine them, unfortunately I suspect the safety cutoff I put in there is causing the car to hate it, so I need to reevaluate.
mknox
Well-Known Member
Yep. A couple of weeks ago, I stopped at a hotel in Battle Creek, MI on my trip and all they had for me was a 120 volt outlet. It was below freezing and I still got an appreciable charge overnight. I kept notes, but don't have them handy to quote actual miles per hour gained, but I believe it was close to, if not the same as what I am used to seeing in the summer. I was really just hoping to have the car "hold steady" overnight, and was quite pleasantly surprised.
green1
Active Member
Ok, so here are the final numbers if anyone is interested:
Vehicle had been parked in my unheated garage at -5c.
Left home charged to 406km, with charging completing as I left and after a full half hour of pre-heat.
I drove 164km starting at -12c and dropping to -22c along the drive, mostly flat, roads clear with some bits of snow/ice. first half travelling 120km/hr, second half travelling 110km/hr
Arrived at destination with 169km remaining and 15 minutes later pluged in to a NEMA 5-20 outlet through a home-made adapter to NEMA 14-50 to allow higher current.
Charged at 116v 17a (I know, should only be 16a, but I cheated...) Car initially reported 9km/hr of charge and thermometer showed -22c
11 hours later charge rate had dropped to 8km/hr
by 15 hours the temperature had climbed to -10c where it stayed the rest of the time
23.5 hours after arrival I started pre-heating and the charge rate dropped to 7km/hr
24 hours after arrival I unplugged to head home, car reported a total of 174km added over the 24 hours.
I then drove 164km home at -10c and arrived home with 104km remaining. which means had I not charged at my destination I would have been about 70km short getting home.
Mitigating factors: I had almost no wind while charging, the battery started fully warmed up from a long drive, and I cheated with the current a bit (this was 17A charging, not 12A charging) Additionally we warmed up to -10 half way through, when we just as easily could have dropped to -35c.
Conclusion: charging on 110v at -20c is still possible, though I do still worry that I could end up at this location in colder weather, with wind which may cause more issues. In light of this I will continue to try to get my "easy 240" adapter complete as that would give me significantly more of a comfort margin.
Vehicle had been parked in my unheated garage at -5c.
Left home charged to 406km, with charging completing as I left and after a full half hour of pre-heat.
I drove 164km starting at -12c and dropping to -22c along the drive, mostly flat, roads clear with some bits of snow/ice. first half travelling 120km/hr, second half travelling 110km/hr
Arrived at destination with 169km remaining and 15 minutes later pluged in to a NEMA 5-20 outlet through a home-made adapter to NEMA 14-50 to allow higher current.
Charged at 116v 17a (I know, should only be 16a, but I cheated...) Car initially reported 9km/hr of charge and thermometer showed -22c
11 hours later charge rate had dropped to 8km/hr
by 15 hours the temperature had climbed to -10c where it stayed the rest of the time
23.5 hours after arrival I started pre-heating and the charge rate dropped to 7km/hr
24 hours after arrival I unplugged to head home, car reported a total of 174km added over the 24 hours.
I then drove 164km home at -10c and arrived home with 104km remaining. which means had I not charged at my destination I would have been about 70km short getting home.
Mitigating factors: I had almost no wind while charging, the battery started fully warmed up from a long drive, and I cheated with the current a bit (this was 17A charging, not 12A charging) Additionally we warmed up to -10 half way through, when we just as easily could have dropped to -35c.
Conclusion: charging on 110v at -20c is still possible, though I do still worry that I could end up at this location in colder weather, with wind which may cause more issues. In light of this I will continue to try to get my "easy 240" adapter complete as that would give me significantly more of a comfort margin.
DavidB
2010 Roadster Sport || 2013 S85 || 2017 X100D
Yes, the NEMA 6-20 outlet. Some motels use a NEMA 6-15 outlet.
I worry about you pulling 18 amps off of a NEMA 6-20 outlet. Unless you absolutely know the wiring inside the walls, you should never draw more than 80% of the amperage of the plug. In this case, you should not draw more than 16 amps. Some motels have very shoddy wiring; I tripped a circuit breaker at one motel drawing 12 amps when plugged into a 6-20 outlet!
-- addendum --
Tesla Motors now sells an adapter for the NEMA 6-15 outlet: Shop: Tesla Motors NEMA 6-15
This adapter will also work for all NEMA 6-20 outlets, but is limited to 12 amps.
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Aqua
Member
That was fun to follow along with. Thanks for the detailed write up and congrats on making it home without issue!
travwill
Active Member
I've used 120v time to to time, adds +4 miles per hour. I actually do it in our work garage sometimes if I start the week on a low % of charge. I can drive to work and use about 8 miles to get there, 8 miles to get home = 16 miles (rated) each day. Plug in though for about 8 hours and it nets me a good ~30-32 miles. In just going back to work it covers my commute and other errands for the day, and nets me gain each day as well.
-T
-T
Most garages have 20A outlets. If yours does you may want to get the NEMA 5-20 adapter for the UMC and then you could get 5 miles of range per hour charging. The difference adds up, especially when parked in a hotel garage overnight.
I currently achieve a 5-6mph charge rate on a S with a 5-20 (a wonderful UMC adapter, IMO!). It wouldn't surprise me one bit if my new Model ☰ will charge at 7mph with a 5-20.
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