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What to expect if I run down my 12 Volt battery

Discussion in 'Prius c Care, Maintenance and Troubleshooting' started by johnhlong, Sep 5, 2013.

  1. johnhlong

    johnhlong Junior Member

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    I have the 2013 Prius C2.

    From time to time I will be running accessories off the 12 volt battery while stopped or parked.

    What troubles am I looking at if I manage to run down the 12 volt battery?

    Can I just leave the car in "Ready" and will it start the car as needed to keep the battery charged. Or will it just run the 12 volt battery down?
    I've been known to go camping and do this for 8-12 hours at a time.

    John
     
  2. B2FiNiTY

    B2FiNiTY Active Member

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    Leave it in ready and make sure you have plenty of gas.

    It will occasionally start and stop as needed.

    Or bring a portable battery charger or spare battery.
     
  3. johnhlong

    johnhlong Junior Member

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    So it will automatically start and stop the gas engine to keep the 12 volt battery fully charged?

    I couldn't ask for anything better. :whistle:

    That and some spare gas just in case........

    Any other drain on the 12 volt battery when the car is in "Ready" ?


    John
     
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  4. vincent1449p

    vincent1449p Active Member

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    When the car is in Ready, the DC-DC Converter handles all the electrical loads on the 12V bus It drops the HV Battery nominal voltage of DC 144 V to approximately DC 14 V. Since 14 V is higher than the Aux. Battery, it is charging the Aux. Battery.

    When the HV Battery SOC gets below 40%, the Power Management ECU will command ECM to start the engine so that MG1 can charge the HV Battery. Once the SOC reaches above 45%, the Power Management ECU will command ECM to stop the engine. The cycle repeats once the SOC drops below 40% again.

    If you do not want to risk running down your Aux. Battery, try to avoid using ACC mode or Ign-On mode, use only Ready mode.

    Vincent
     
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  5. johnhlong

    johnhlong Junior Member

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    Slick. That will work great for my needs.
    Basically a big, expensive, mobile 12 volt generator :sneaky:

    When in Ready only mode is 12 volts available at the cigarette lighter socket or do I need to connect directly to the 12 volt battery?

    What does SOC stand for?

    John
     
  6. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    I will add that you do NOT want to be in N, you want P. You can't recharge the HV Battery in N. (Toyota is legally required to have an N, but you want to avoid ever using it)
    Yes, the cigarette lighter (Power point) is powered in Ready.
    State of Charge is how 'full' the HV Battery is.
     
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  7. johnhlong

    johnhlong Junior Member

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    Everything I ever wanted! AND it only cost me $20,000.
     
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  8. bisco

    bisco cookie crumbler

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  9. Andyprius1

    Andyprius1 Senior Member

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    . That is definitely one of the sweeter points about the C, makes me tend to wonder IF I should have bought the PIP last year! But, no regrets, the PIP will be my 110V EV and the C will be my excursion car. I have only had the C for about 30 miles and am absolutely amazed at the mpg. It seems far more efficient than the other straight Toyota Hybrids. WHY ? , lighter? Better technology, what.??? I am busy returning to my hypermiling techniques.
     
  10. Andyprius1

    Andyprius1 Senior Member

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    Incidentally, as far as I can see, the C is not only the least expensive. But seems to be the best in MPG also.
     
  11. Rob.au

    Rob.au Active Member

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    The c's strength is in city driving, most likely due to its lower weight. Out on the freeway, the liftback's better aerodynamics for lower drag give it the advantage.
     
  12. Andyprius1

    Andyprius1 Senior Member

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    Very true, but I see a lot of posters commuting 40-80 miles at 75 mph, so I guess the C can take it........?
     
  13. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    Yes, if you already own a c, freeway commutes are fine. If you are looking, other Prius do better on freeways.
     
  14. Rob.au

    Rob.au Active Member

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    Take it? Cruising at 75 down a freeway is nothing for a c. The liftback will beat it on fuel economy due to the reduced drag, but there's no issue with capability.
     
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  15. minkus

    minkus Active Member

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    Though unless you find a better deal on the liftback than on the c and/or if you drive 90% on the highway, the ~$5,000 more you'll pay for a ~2-4 mpg gain (from ~46 to ~49 mpg) in the liftback won't pay for itself.
     
  16. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    Correct. If my job fit in a c, it would only cost $140 more a year for me than a Liftback (my job just barely fit in a liftback, but is much easier in a v)
     
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