TMC is an independent, primarily volunteer organization that relies on ad revenue to cover its operating costs. Please consider whitelisting TMC on your ad blocker or making a Paypal contribution here: paypal.me/SupportTMC

Supercharger: Charge longer & drive fast or charge shorter and drive slower?

Discussion in 'Battery Discussion' started by ratsbew, Mar 7, 2014.

  1. ratsbew

    ratsbew Member

    Joined:
    Mar 3, 2012
    Messages:
    371
    Which allows the overall fastest velocity? Charging to 100% and driving the speed limit to the next supercharger or doing a quick charge and driving slower at a lower kWh/mi?

    Obviously the speed limit and various factors play into this, but generally speaking is it best to do a quick charge and drive slowly or a long charge and drive quickly?

    I don't own a Tesla so my guess is once the miles/hour of the rate of charge equals the speed limit then you should unplug as long as you have enough miles to reach the next station.
     
  2. landover

    landover Member

    Joined:
    Jan 17, 2014
    Messages:
    89
    Location:
    Pleasant Prairie, WI
    It all depends on how much time you have to charge. The faster you drive the more power you will use. The slower you drive the less you have to wait and charge. But the lower the percentage is on your battery, the faster you can charge at a supercharger.

    With that said, you are always better off driving slower then driving faster and charging for longer.
     
  3. Zextraterrestrial

    Joined:
    Mar 11, 2010
    Messages:
    3,636
    Location:
    Humboldt/Los Altos
    #3 Zextraterrestrial, Mar 7, 2014
    Last edited: Mar 7, 2014
    ..but when you can charge at 200-400mph vs drive at 70-80mph ...
    (should note that driving much faster will pull off more mph than the speed you drive so there is probably an inflection point, if that makes sense?)

    drive faster and get to the SC with the lowest SOC that you can
    never charge to more than 80-90% or less even depending on your speed/range comfort

    with a 140 mi spacing between SC + hills and ~40F if you get to 200 rated mi you can drive pretty fast(ticketable mostly) and get to the next SC with ~ 0mi
    at least in my experience, which doesn't include much of the SC speed trips


    say I drive 1) 60 mph vs 2) 75-80 mph and use 1)rated(~300Whr/mi) vs 2)more(~400Whr/mi)
    and go 120 miles.

    1) I will get there in 2 hours and need ~120mi range
    2) I will get there in <1-30 min and need ~180mi range

    30 mi charging will get me to 120 rated + ~ 15 min to get to 180

    1) starting w/ 0 at first SC charge to 120 (1/2hr) drive 2 hr charge 1/2 hr . . .so 2 -1/2 hr per cycle
    2) starting w/0 charge 45min drive ~1 1/2 hr charge 45min .. . . so 2 1/4 hr per cycle

    this is with only 90kW supercharging too
    ..but, if others are sharing chargers then I would think driving slower might be safer since you will be limited on SC charge rates a little
     
  4. Mnlevin

    Mnlevin Member

    Joined:
    Feb 4, 2013
    Messages:
    417
    Location:
    South Florida
    I agree with Z above. I have done a few trips with my 60. If I have 140 mi between chargers I can fill up to about 85% (160) and drive 70 mph and still get in with about 15-20 miles left. IF I had a 85, I would probably charge to about 65% between chargers. This is all on the east coast, where it is flat. Probably something different out west or in very cold climates. But if you take what you need to run 70mph between chargers it can only take about 40 minutes to charge up because it slows down after that.
     
  5. Zextraterrestrial

    Joined:
    Mar 11, 2010
    Messages:
    3,636
    Location:
    Humboldt/Los Altos
    hills just add to your effective speed as does climate and moisture + road surface
    my example was ~ from Springfield to Grants pass (really 140 miles but I cheated the times a bit + it was rainy and I was going much faster for parts)
     
  6. David99

    David99 Active Member

    Joined:
    Jan 31, 2014
    Messages:
    2,048
    Location:
    Brea, Orange County
    The most important, as others have pointed out, is the state of charge when you arrive at the Supercharger. The lower the battery, the faster it will change thus shorter wait. So when doing a long trip across many Superchargers, charge only as much as you need to get to the next one arriving at low state of charge. That's the best way to shave off time of your total travel time.

    I also calculated a few examples of different driving speeds plus charge time. It turns out you are overall faster when you go at higher speed. The reason is that charging is happening at much faster speed than you drive. The difference is not big though. It's only a few minutes for each 100 mile leg, which is the average distance between the SC. In other words, there is no point on going slow on freeways. Go with the flow or faster if you can and it's safe.
     

Share This Page