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Oh what a difference 40 degrees F makes.

Discussion in 'Model S: Battery & Charging' started by Liz G, Nov 23, 2013.

  1. Liz G

    Liz G P03056

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    #1 Liz G, Nov 23, 2013
    Last edited: Nov 24, 2013
    About once a month I've been heading up to Milwaukee to visit my grandmother. So, I've gotten to be very comfortable with the drive and knowing how much range I need given various weather conditions (sun, rain). So as I prepared for my latest trip I assumed it would be relatively stress free. I got my car in January, so I know (or at least I thought I knew) what to expect heading up north now that the temperatures were dropping.

    Oh, but what a difference 40 degress F makes.

    So I usually leave the house with around 254 miles of charge, then hit Normal which is 203 miles away, then Rockford (another 124 miles) then head up to the hotel in Milwaukee (86 miles from Rockford). I've been driving 70 to 75 mph all the way up this summer. I usually arrive in normal with 30 miles to spare and Rockford and Milwaukee aren't even an issue.

    Now, in addition to the dropping temperatures (it was 37 degrees F when I left home), I also have new tires (Hankook 19s, used to have the Goodyears) and the dreaded 5.8 with no lowering is installed. But I figured I was ok. I'd do a range charge, run speed limit and keep the thermostat at a reasonable temperature. No problem. Right.

    So, my first surprise was my range charge. The car only charged up to 251 and then after I heated it up I ended up leaving with only 249 miles of range. Ok no problem. I figured the slower speed would make up for leaving the heater on so I headed out at a steady 65 mph with the heater set at 72. About 30 miles east of St. Louis I realize I am running thru my buffer like crazy. I had already consumed 17 mile of buffer and had barely covered a 1/4 of the distance. It was 37 degrees out. We were consuming 359 Wh/m. Way too much. So my son turned off the heat and I slowed down to 60. That was with about 160 miles to go. So huddled under a blanket and only getting a little heat in the car when I needed to defrost the windshields we made it to Normal with 14 miles remaining.

    The rest of the trip was relatively smooth. With the short distance to Rockford and Milwaukee we just charged a little longer and had enough buffer to run speed limit (65 mph) and keep the heat on 72 degrees. By the time we hit Milwaukee we were using 394 Wh/m. Crazy. But doable.

    Can't wait till we get the Supercharger between Normal and St. Louis will make these runs much smoother.

    Not looking forward to the ride home. It's supposed to be even colder, so looks like that stretch from Normal to home will be slow and a bit nippy. Glad I had the forsight to bring a blanket.

    Hope this helps others not make this same mistake. It's easy to get complacent about the range when it's warm out.
     
  2. caddieo

    caddieo Member

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    I'll have to keep this in mind when the supercharger build-out allows me to go from FL to Chicago - a trip I now make in an ICE 3-4 times a year.
     
  3. JohnQ

    JohnQ Active Member

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    Liz, I know cold makes a difference (along with the heater) but do you think you had headwinds that day? That's pretty significant consumption you had there …
     
  4. purplewalt

    purplewalt Active Member

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    Liz,
    Perhaps you might consider starting out your drive a little slower speed, and then your range buffer remains intact.
    I generally use 30 Miles of range as my buffer.

    I just did a very long drive (3,000 miles) through the Southeast using one SC, 61 MPH was my optimal speed when temperature was nice, dropped to 58 MPH in mountains and cooler climate.
    Cruise control works great, in conjunction with the GPS to confirm the amount of range + buffer you still still have.
    A different driving strategy to employ for when you have to get there, and you DON'T have the luxury of knowing a SC will at your next destination.
     
  5. Liz G

    Liz G P03056

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    It's possible. Could also be the new tires or the fact that the car no longer lowers at high speeds. Or a combination of all of the above. I was just really surprised, it used far more than I expected based on last year's winter driving experience.

    - - - Updated - - -

    Good point. I do use all of those when road tripping, hence I realized before it became critical that I would have to slow down more. I thought I was starting out slow enough doing 65 vs my usual 70-75, but apparently that wasn't enough.

    Oh well. Learning to drive the Model S is an ever evolving experience. Just hope others have the opportunity to learn from my experiences.
     
  6. Todd Burch

    Todd Burch Electron Pilot

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    Liz, try the run with the seat heaters on instead of the cabin heat. They consume much less power. Or, if that's not warm enough, leave cabin heat at something like 65, letting the seat heaters do the rest.

    Also, preheat well in advance while plugged into shore power so that getting the cabin and pack nice and toasty doesn't consume any range.
     
  7. wormhole

    wormhole Banned

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    The no lowering has minimal impact on range, a few miles here or there...the bigger concern was why your car only charged up to 251 rated miles, are you sure you fully charged it?...I have noticed a difference in colder weather (note that on the TM website turn the temp to 32-degrees and put the heat on and range goes to 218)...that said, I've still been averaging about 330wh/mi in 40 degree temp here in NY....cold is definitely the achilles heal of the car no doubt.

    Here is what I have found....1) believe it or not, turn AC off, there are times when it actually goes on when its cold, when the car, after people being in it and it heats up, turns on. This is a flaw in the software that I hope is rectified. I noticed this the other day when I felt cold air coming out of the vents despite it being 40 degrees out and the interior temp set to 69...2) keep the fan set at 2 or 3 or something...when the fan starts when you first heat up the car, i've found it increases wh/m.

    Having made these changes the other day, I drove back and forth to NYC, about 80 miles, averaging 68 and averaged 309 wh/m in about 40 degree weather...
     
  8. Todd Burch

    Todd Burch Electron Pilot

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    Wormhole's got a few good tips there. Not sure about the A/C software bug as I haven't experienced it myself--probably because I turn A/C off in that case anyway. But it sure can't hurt to turn A/C off.

    My daily commute on the highway, when it's around 40 degF, consumes about 310 Wh/mi at 70mph. Of course, sky conditions have a big impact here. Sunny days will require much less cabin heat, regardless of the outside temperature.
     
  9. huntjo

    huntjo Member

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    Why set the temperature to 72? Are you wearing shorts and a t-shirt in the middle of winter? Sorry of course it is all personal preference, I just always bicker w my family about the thermostat. But seriously, I think in 35 degree weather you're going to be a little bundled up already, so just do seat heaters and set the HVAC temp to like 66-68 in econo-mode. Much less draw on your power.

    I bet somebody has made a curve for HVAC set points with regards to energy use in a given outside temperature (similar to the speed vs energy use that is related to wind resistance), but not knowing the exact numbers, I would just say: don't try to recreate summer in the middle of winter and expect low energy use.
     
  10. Liz G

    Liz G P03056

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    Well made it home. Temps were averaging 14 to 17°F. The trip to Normal wasn't bad. Ran speed limit and had the thermostat set to 70. The trip from Normal to home was a bit uncomfortable. Set the cruise to 60mph and the thermostat to 68°F, fan on 1. We ended up making it with 6 miles to spare.

    Was really cold though. We were both huddled under a blanket. The colder it gets outsde the draftier my car gets. I had to run the defroster every 15 mins or so to keep the fog off the windshield and my side windows actually frosted over. I'm taking the car in after Thanksgiving to have them look at it. Hopefully, they can figure out were the air leak is. It feels like its coming from the little triangle window.
     
  11. islandbayy

    islandbayy Active Member

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    Liz, similar problem with my 60. Drove to the Dells Friday Night, usually arrive with a 40-50 mile buffer. Arrived just as it ticked 0, and I limped it the last 3 miles at 25mph. I have been experimenting with temps. It was 3-5 degrees last night, so my car cold soaked after charging, by running the heat to pre-heat the cabin, I GAINED about 8-10 miles just from heating the battery pack (No charging involved!).

    I did a range charge yesterday, it was 15 degrees out here in the Dells, Drove to Maustin to see the new, secretly built and 95% complete Supercharger, then back to the dells, then baraboo, then dells again. In all, I finished the day with 40 miles left on my S60, and went a total of ~80 miles. Usage was about 480 w/mile, and just keeping the cabin comfortable. I felt the cold breeze as well, couldn't quite track down the location.
     
  12. teslasguy

    teslasguy MSP P#1117

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    The leaking air around the little triangle window is a long known issue. There is a factory fix which involves installing a shim (washer) in the window raising mechanism as I recall. Fixed mine.
    As far as the toll cold weather takes, I don't count on more than 200 miles MAX in really cold weather. I have a P85 and running 19" Bridgestone Pole Potenzas. As best I can determine the poor rolling resistance shaves around 15-20% off my mileage in cold weather. I've also noted that since 5.8 I don't think my energy consumption has been below 400 wh/mi. I average around 425 wh/mi. Before 5.8 I averaged around 385 wh/mi, and that was with both my 21" Contis and my 19" Bridgestones. And I've become a pretty sedate driver as I've now had my car about a year and a bit of the early "I bet I can beat this guy" adrenalin has worn off.
     
  13. wormhole

    wormhole Banned

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    I have th exact same finish problem. Huge draft through driver side triangle at front of window. It's going in for replacement in a week or so.
     
  14. pgiralt

    pgiralt Active Member

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    Liz, glad you made it home safe. Just curious - when you were running the heat, did you have it set to Range mode (ECO) or were you in standard mode?
     
  15. Liz G

    Liz G P03056

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    Good to know they have a potential fix. That air leak is why I usually have my heat high. I get the cabin warm while I'm charging then as soon as I get on the highway I feel the temp in the car drop.

    - - - Updated - - -

    Yes. I keep it set to eco/range mode all year long, as in the summer it keeps the fan from coming on full blast when the car is trying to cool the cabin. Takes a little longer to cool the cabin but you dont have the loud fan noise when you're driving thru the parking lot.
     
  16. skdave

    skdave Member

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    Welcome home Liz.
     
  17. rdalcanto

    rdalcanto Member

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    I drove from Salt Lake City to Park City and back yesterday morning to take my son to ski practice. It was 10 degrees. Normally going up and back doesn't use that much more energy than a relatively flat drive, because I recharge all the way down. Yesterday I used 80 miles of range to go 53 miles, and that was starting with a warm car from the garage, and thermostat at 69. No question the heater is a big range killer, unlike the A/C which is negligible. I have not changed to snow tires yet, but will do that soon (forecast looks good for the next week).
     
  18. Liz G

    Liz G P03056

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    Thanks Dave.

    Oh and for any media types out there reading this forum entry.... I still love my car and trust the guys at the service center to figure out a way to resolve the air leak.
     
  19. SCW-Greg

    SCW-Greg Active Member

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    Great input from everyone. Thanks for sharing.

    We have a trip to East Seattle coming up (about 185 miles), in temps I expect around 40. This is a well proven trip by many from both Portland and Seattle - in warmer weather. I don't like to compromise when driving, in terms of speed or comfort, especially when the wife and kids are riding along.

    When I arrive, I'll only have access to 110, 12A power, for 3 full days, but no doubt there will be some daily short trips while we're there too. Overnight it will likely drop down to 28 degrees. So I suspect I may not gain too much from the 110, as it will likely just be preserving battery temp.

    Fortunately, I-5 is now covered with Superchargers. All this cold range talk, has me thinking I better stop at Centralia (2/3 of the way there) and spend 20 mins to top off a bit. Might need it on the way back too.
     
  20. Doug_G

    Doug_G Lead Moderator

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    That is in line with my experience as well. Last winter I did a leg of 304 km and had 30 km (projected not rated) remaining. This was at -20C in a nasty blizzard, so rolling resistance was even worse due to snow on the highway. Traffic was slow so speeds were 80-90 kph. Heater was on in Range mode. I was never concerned about making my destination due to the excellent Energy App and GPS displays, but that was kinda pushing things since there were no charging opportunities anywhere along that route.

    (Imperial version... 190 miles, 19 projected, temperature -4F, speed 50-55 mph.)

    In my experience, on a dry road there is little impact on range at +3C (37F), but by the time you drop to -3C (27F) there is substantial impact, especially on short trips where you get the extra impact of pack heating. So transitioning through the freezing point is where the range loss really kicks in. Same thing for Roadster.
     

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