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Driving Over 80 MPH Will Cost You

Discussion in 'Prime Fuel Economy & EV Range' started by axle2152, Oct 28, 2018.

  1. m8547

    m8547 Senior Member

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    Ignoring discussion of speeding or MPGs, driving 80+mph in EV mode can't be too good for the battery. If we assume you only get 20 miles of EV range at 80mph, then you could fully discharge the battery in about 15 minutes. If you think of it the other way, charging in 15 minutes would make a ton of heat and require special cooling. Discharging doesn't make as much heat as charging, I think (it still does make some), but it can't be great for it with the relatively weak cooling we have. If you assume 6kWh usable capacity, draining it in 15 minutes is 24kW.

    Some of the interstates in empty parts of Utah and Wyoming have 80mph speed limits. And since my speedometer reads a couple MPH high, I could go 84mph (EV mode limit) according to the car while actually going maybe 1mph over the limit.
     
    axle2152 likes this.
  2. padroo

    padroo Senior Member

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    I avoid interstate highways when I can.
     
  3. benagi

    benagi Active Member

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    Not me. Got my first speeding ticket back then at age 29.
     
  4. axle2152

    axle2152 Active Member

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    I don't think you're going to hurt the battery, the ICE will start if the ECU (or whatever computer module that's in charge) thinks there's too much current or if the battery temperature gets too hot (or if it's too cold). I've had this happen a few times going up steep mountains, the ICE starts up and takes charge until the load is taken off. The battery pack has a max output of 66-68 kW depending on SOC.

    I have to say that with my 2016 Prius, taking the back roads does boost fuel economy over interstate driving (shocking right?). I go to Wilmington, NC a lot and I live in the SW corner of NC, so normally I go from I-85 to I-26 and then I-20 then I-95 and finally US 74 in to Wilmington. Sure, I could just go I-40 but it is an extra 100 miles. I once decided to make my own route and avoid interstates all together. Ended up being about a draw on distance (because I made a couple mistakes, wrong turns) and did take about an hour or so longer. The nice thing, so much less traffic, and less towns to go through but easy driving for the most part otherwise. On the flip side because it is more rural if you have trouble, might find yourself in a bit of a pickle. Aside from that yes the Prius, or any car really will like speeds under 70. Just not very often these days where you can drive 400+ miles and keep it under 70....at least in my neck of the woods.
     
    Mendel Leisk likes this.