Being in "idle" with the Prius. . .

Discussion in 'Gen 2 Prius Fuel Economy' started by Mag Gris, Apr 3, 2008.

  1. Mag Gris

    Mag Gris New Member

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    When I'm picking up my kids at school, I'm usually listening to NPR or music on the radio . . . With our other non-hybrid vehicle, I would turn off the engine rather than idle (to minimize emissions, save gas etc.), and then turn on the auxiliary (?) power just to keep the radio on.

    This is probably a dumb question, but with the Prius, when I put it in park, am I essentially just using battery power, so that I don't need to turn the car off first? I've been turning it off, then repowering (w/o my foot on the brake) to turn on the radio while sitting there. Hubby says I don't need to turn it off; nothing but the battery is on once I'm in "park". Is he right?

    Thanks!
     
  2. bestmapman

    bestmapman 04, 07 ,08, 09, 10 and 16 Pri

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    It depends on how long you are going to sit. If it is for more than 5 minutes you may want to power down and go to aux. The reason is that by sitting there in ready mode you will run down your SOC. This will be hard on your FE as the ICE will have to run to charge the SOC again once you get going again. If you use the Aux, then you will be using less of the battery and not run the SOC down as much. You will have to go through S1 on start up, so it depends on your situation.
     
  3. qbee42

    qbee42 My other car is a boat

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    Not a dumb question. There are several factors in your decision, so I will give you more information than you need, but that's what engineers do:

    1) When in park, the Prius uses very little power. However, it does use more power than sitting in ACC mode running the radio from the battery.

    2) Restarting the Prius uses some fuel while it goes through its power-on cycle.

    3) The 12 V battery in the Prius is very small. You can drain it fairly quickly by running accessories in the ACC mode.

    4) In park, the Prius will run the engine as needed to recharge the battery and supply heat.

    So what is the answer? If you are sitting for a while on a nice day with the windows down, it saves a bit of power to turn off the engine. If you are sitting for a brief period of time, it's better to stay in park so the engine doesn't have to go through a starting cycle. If it's cold or hot, you may want to stay in park for heat or air conditioning. Regardless, you aren't going to hurt the car.

    Tom
     
  4. Mag Gris

    Mag Gris New Member

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    Whoa that's a mouthful of acronyms! :eek: Where's the glossary?! I just don't know Prius-speak so well yet and even flipped thru the manual to see if I would find them but didn't. I appreciate the reply . . .but wish it was in English! :D
     
  5. Mag Gris

    Mag Gris New Member

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    Whew, now this I can understand. ;) Thanks for the detailed explanation qbee42! Makes perfect sense.
     
  6. JimboK

    JimboK One owner, low mileage

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    What Tom said.

    You probably won't find those abbreviations in the manual. We Prius owners have developed our own unique language, and we sometimes forget we're talking to foreign-speaking newbies. :)

    If you still want a glossary, here's a context-sensitive one:

    SOC: State of charge (of the hybrid battery)
    FE: Fuel economy
    ICE: Internal combustion engine
    Aux: Auxiliary power, or "accessory" mode with the Power button -- ignition off but radio can run
    S1: Stage 1 of the five stages of the Prius warmup cycle (careful, some might suggest this is not in English ;))
     
  7. ibiwisi

    ibiwisi Flathead Lover

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    I brought my 2003 from upstate NY to Central Ohio on a car dolly in the big snow storm in March. We ran the 4 ways on the Prius because the tow dolly lights gept getting covered up. I started the car, set the heater temp on 60 and took off. When the temp in the car reaCHED 60 THE ICE would shut off and when the temp got down to about 55 it would start again on it's own and run until it got to 60. 12 hours of this and we got home only to fine snow so deep we couldn't get in the driveway but no adverse effects on the Prius.
     
  8. Winston

    Winston Member

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    I personally do not like to use the ACC mode since it will accellerate death of the tiny Prius 12V battery. I prefer to leave it in Ready mode which powers everything from the big traction battery. Plus, if you go to ACC, then you will waste any fuel that you might have saved (due to the lower amp draw in ACC mode) when the car goes through the S1 stage. I really dont think there are many scenerios where you will save energy by going to the ACC mode in your situation.
     
  9. Wa1hog

    Wa1hog Old Blind Hippie

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    I was having lunch today with my wife and decided to keep the car and AC runnming.
    What I noticed was that the battery level was droping into the purple. Will the ICE start up on its own and recharge the batteries?
     
  10. qbee42

    qbee42 My other car is a boat

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    Yes, the Prius will start the ICE and charge just for a bit, then shut it off again. This cycle will continue until you run out of gas.

    Tom
     
  11. icarus

    icarus Senior Member

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    If you run with the headlights on, or have dtrl's sitting for long periods in "ready" will force the engine to run more just to keep the 12vdc battery charged.

    Put in "accy" listen to the radio for 1/2 hour. Won't be enough drain on the battery to worry about,

    Icarus
     
  12. patsparks

    patsparks An Aussie perspective

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    Eat garlic, cabbage and baked beans for lunch, then it should take longer before you run out of gas.
     
  13. qbee42

    qbee42 My other car is a boat

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    How about an egg salad sandwich, chili, and a beer. That should do it.

    Tom
     
  14. Prius 07

    Prius 07 Member

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    ...and please leave your windows down ... a diagonal cross wind would be ideal LOL;)
     
  15. Erock67

    Erock67 Junior Member

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    Just wondering about how long it takes for the battery to go from max blue bars to purple bars when parked in the ready mode running ac?

    I decided to nap at a rest area, and it got down to two purple bars then ICE kicked on. It shut off before making any blue bars appear. It took about 25 minutes for it to reach purple bars .

    SM-N950U ?
     
  16. bisco

    bisco cookie crumbler

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    sounds exactly right, it won't charge beyond purple until you start driving. time depends on heat and humidity and sun.
     
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  17. Erock67

    Erock67 Junior Member

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    Awesome, thanks! I just wanted to make sure it was operating normally.

    SM-N950U ?
     
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