Well that wasn't fun!

Discussion in 'Model 3' started by bwilson4web, Feb 5, 2022.

To remove this ad click here.

  1. bwilson4web

    bwilson4web Well-Known Member Subscriber

    About 8:30 AM, my wife announced she needed to be in Murfreesboro TN, ~91 miles away for a 10 AM grandson game. I had increased the SOC from 67% to 75% and it indicated 164 miles. But I had not anticipated:
    • +20 mph, 26 F, headwind
    • need to be there at 10:00 AM so I drove 75-79 mph
    • car had cold soaked overnight
    The navigation system routed us via Manchester SuperCharger bumping the distance from ~91 miles to ~118 miles. The lifetime 229 Wh/mi became 364 Wh/mi, a 59% decrease in efficiency. We missed the game but thanks to AutoPilot and the Manchester TN SuperCharger, we arrived in Murfreesboro. Picked up her grandkids and returned via Manchester SuperCharger. She has been work two jobs so I and AutoPilot did all of the driving.

    On the trip:
    • 364 Wh/mi * 118 mi ~= 43 kWh, 86%, for aged ~50 kWh pack after 60 k mi
    So I'm increasing my charge level to 90% during the winter. If we need to make another, unplanned, subfreezing dash into a headwind to Murfreesboro, we should be able take the shorter, direct route without having to route via a SuperCharger.

    Lesson's learned.

    Bob Wilson
     
    Last edited: Feb 5, 2022
  2. To remove this ad click here.

  3. bwilson4web

    bwilson4web Well-Known Member Subscriber

    One late thought is to schedule preconditioning departure at sunrise, 6:45 AM. For the cost of some electricity, the car should be ready to go in daylight and last through most of the morning.

    At 3:30 AM, it is 24 F outside and the car has been cold soaking since I got home about 4:00 PM. So I've scheduled pre-conditioning for 6:45 AM. My JuiceNet 40 Pro should record the amount of energy need.

    Bob Wilson
     
  4. bwilson4web

    bwilson4web Well-Known Member Subscriber

    I've got a preconditioning power graph:
    precondition.jpg
    • Scheduled for 6:45 AM, 25 F external temperature
    • 5:40 initial block to top off the cold soak battery
    • 5:45 steady 3.8 kW to warm the battery?
    • 6:25 variable slope consistent with cabin warming
    • 6:45 block to top off the warm battery
    • 6:55 taper to maintain cabin warmth
    • 7:05 end of cabin temperature taper
    Bob Wilson
     
    Bram Seynhaeve likes this.

Share This Page