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Portable non-gas generator charging Prime

Discussion in 'Prime Main Forum (2017-2022)' started by pianohawk, Nov 13, 2017.

  1. bisco

    bisco cookie crumbler

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    is there anywhere you can plug in and walk to work?
     
  2. bisco

    bisco cookie crumbler

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    did you consider volt before making your purchase? (just curious)
     
  3. priuscatprimeguy

    priuscatprimeguy Senior Member

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  4. priuscatprimeguy

    priuscatprimeguy Senior Member

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    a battery powered one would require a YUUUGE battery or batteries
     
  5. Lee Jay

    Lee Jay Senior Member

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    No, the title of the thread includes "non-gas". There's a really high-quality gas one already built into the car.
     
  6. Since2002

    Since2002 Senior Lurker

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    Okay I think I understand now what you are trying to do (Lee Jay caught it faster than the rest of us). You want to use what is essentially a portable battery with built-in inverter, and charge it at home during the day using your solar power. Then you would carry it to work the next day in the back of your Prime, and then while you are teaching your morning class you would use the portable battery to partially recharge your Prime. The idea being that since you would be recharging the portable battery at home using solar, your only cost would be the one-time purchase of the portable battery, then after that any of the supplement charging using this method would be free.

    The generators (i.e. battery/inverter) in your original post seem to cost about $200 and supply about 0.2 kWh of power if I am reading the specs correctly. Others can do the math but I will take a WAG that this might get you 3/4 mile of EV range. And I assume that you can only do this on Mon, Wed and Friday, correct? Because you will be charging the portable battery during the day on Sunday, Tuesday, and Thursday.

    So 3/4 of a mile three days a week equals just over two miles per week of "free" EV range. Driving your Prime those two miles in HV mode would use maybe .03 gallon. At let's say $2.50 per gallon that's about 8 cents a week that you would be saving (a little more if gas prices go up). Unless my numbers are way off.

    As Lee Jay pointed out you can scale up, but at even greater cost, and then you would have to start factoring in the weight of carrying around those large batteries.

    Yes everyone would like to charge somewhere for free, a lucky few are able to.
     
    #28 Since2002, Nov 14, 2017
    Last edited: Nov 14, 2017
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  7. bisco

    bisco cookie crumbler

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    too bad the solar roof isn't available in n/a.
     
  8. Trollbait

    Trollbait It's a D&D thing

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    If you are just going to be carrying this charging rig in the car, it might be simpler to increase the Prime's current battery.
    Even simpler would be to trade the Prime for a Volt, Bolt, Ioniq Electric, or new Leaf.

    To increase the amount of home solar electricity used to actually charge the car, and to also power the house in the dark, get a Powerwall.
    Powerwall | The Tesla Home Battery
    It is a 13.5kWh usable battery, and costs $6200 to give an idea of how much a battery power supply for charging the Prime while away will cost.
    That would only add about 3km per day(IIRC), and might boost hybrid efficiency a little bit. For $3000.

    Really, if you want the most EV miles per day, just getting a car that already has them is the most cost effective way.
     
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  9. bwilson4web

    bwilson4web BMW i3 and Model 3

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    Use the Prius Way: EV to reach highway cruise speed and then put the car in "HV" mode where it will continue in EV for about a minute to warm-up the engine. HV mode will power the car the rest of the way and provide at least 56 MPG and preserve the EV charge. Do the same in the reverse direction. If you insist on maximum home charging, use 3%/mile to determine when to switch from HV to EV mode.

    A second, universal approach is to use "PlugShare.com" to identify free charging stations between work and home. An L2 EVSE takes a little over two hours to fully charge the car, one hour for half charge. If lucky, you'll love eating fresh produce every night or an after work, adult beverage.

    Of course you could take a $7,000 depreciation loss on your Prius Prime so you'll pay an additional $10,000 for a Chevy Volt without the Prius Prime safety features. If you plan to add the Prius Prime safety features, you'll pay about $15,000 for the Volt or Bolt upgrade. Your money, enjoy.

    Bob Wilson
     
    #31 bwilson4web, Nov 15, 2017
    Last edited: Nov 15, 2017
  10. bwilson4web

    bwilson4web BMW i3 and Model 3

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    I was in a hurry and didn't clearly describe how to drive a Prius beyond EV-only range:

    GOAL: maximize Prius Prime efficiency when the trip range exceeds EV range
    1. Use EV mode to reach the highest speed of trip - this uses the cheapest power, electrical, handle the worst case operating range of an engine when it is cold and the car has to accelerate. Use EV to put the car in its highest cruise speed.
    2. Switch to HV mode - the car will spend about another minute while the engine comes on at a low power, warm-up mode. Then it will take over sustaining the speed at an peak efficiency operating mode.
    Now if the goal is to fully use EV each day, use ~3%/mile to figure out when to return from HV to EV mode when approaching the final destination. For example, say the battery is at 12%, 12/3 ~= 4 miles. Switch to EV mode when 4 miles from home.

    Bob Wilson
     
  11. Since2002

    Since2002 Senior Lurker

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    Wouldn't it be the rule not the exception to want to fully use EV miles each day?
     
  12. bwilson4web

    bwilson4web BMW i3 and Model 3

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    Yes and no. It is easier to use the EV capability for every warm-up and make the Prius Prime into a dependable, consistent, 65-75 MPG car. But from a minimum cost standpoint, especially with affordable electricity, the trick is to use the 3%/mile rule of thumb and arrive at the charger in the 1-5% range. The risk is avoiding another engine start event with less than a mile to home. Engine start events are fuel expensive especially at low speeds.

    Bob Wilson
     
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  13. Since2002

    Since2002 Senior Lurker

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    I would think that most trips that go beyond EV range will include some highway or freeway, so when that's the case couldn't you just make sure to run out of EV while you are still on the highway and run HV the rest of the way home. The next morning when you start out you will have a full EV charge and shouldn't have to warmup until you are on some type of highway again. I realize the common wisdom seems to be to use EV miles for the lower speed parts of a trip but I would guess that whatever savings there might be would be offset by sacrificing a couple of miles of potential EV driving each day. I realize that poorly timed warmup cycles are not good but if you can manage when warmup cycle occurs when running out of EV then you could use all of it.
     
  14. bwilson4web

    bwilson4web BMW i3 and Model 3

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    I'm using the scenario that there is a daily commute with two trips. So you might want to reserve enough battery at the end of the morning trip to handle the warm-up and acceleration to higher speeds on the way back. The strategy I'm proposing is to use EV to maximize HV performance. A perfect trip arrives at home with 1-5% remaining so as to avoid an extra engine warm-up cycle.

    Bob Wilson
     
  15. Since2002

    Since2002 Senior Lurker

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    Maybe you are thinking of someone who can charge at work. I'm thinking of someone who charges only at home, in which case for sure they will want to have EV remaining when they arrive at work to avoid warmup that starts in the parking lot when they leave for the day, or drive somewhere for lunch, etc. But I would still think the perfect trip arrives home with 0.0% remaining, not by trying to cut it that close which of course creates risk of warmup just before you arrive home, but by a well-timed warmup when the EV runs out. You would still try and use EV for low speeds and HV for high steady speeds, but then try and time it so that you run out of EV no later than say two miles from your freeway exit on the way home.

    It would be time consuming but maybe one day someone could make a chart of several different commute scenarios, showing what energy is used for each segment including wasted warmup energy (energy that doesn't go into moving the car forward). But the chart would also need to include wasted EV range, i.e. leftover EV. It just seems like being in a baseball game and getting three outs and leaving someone on base.
     
    #37 Since2002, Nov 16, 2017
    Last edited: Nov 16, 2017
  16. bisco

    bisco cookie crumbler

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    50 mile commute one way, no charging at work. see post #16.
     
  17. Since2002

    Since2002 Senior Lurker

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    That was the OP and part of the original discussion about their idea to haul a pre-charged portable battery to work. As far as we know they either gave up the idea based on the feedback, or they are still researching the links to the various multi-thousand dollar systems that would make their idea happen. Meanwhile everyone else seems to have moved on and is now discussing how to get maximum efficiency in a commute. Could use the OP's commute as an example but I think would need to know more details about the route not just how long it is.
     
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  18. bisco

    bisco cookie crumbler

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    i guess i moved on as well.:cool:
     
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