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Relationship between ICE and HV battery and 12v battery

Discussion in 'Gen 3 Prius Main Forum' started by Johnny Cakes, Jan 18, 2017.

  1. Johnny Cakes

    Johnny Cakes Senior Member

    Joined:
    Dec 30, 2016
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    Location:
    Virginia, USA
    Vehicle:
    2015 Prius
    Model:
    Five
    I'd like to get a better understanding of the relationship between the ICE and the batteries.

    Are these statements true?
    1. The 12v battery is only charged by the HV battery.
    2. The 12v battery is never charged by the ICE
    3. The HV battery is only charged by the ICE (and regenerative braking)
    4. Assuming the car is in READY mode and PARK, the 12 volt battery should never loose its charge (assuming the ICE can self-start -- i.e. gas in the tank).
    5. Likewise, assuming the car is in READY mode and PARK, the HV battery will always be kept charged.
    6. The A/C runs solely off the HV battery.
    7. The various electrical accessories (e.g. USB port, 12v cigarette) run solely off the 12v battery.

    I did a search and read a bunch of threads to lead me to these conclusions, but wanted to make sure I was understanding this correctly.

    Finally -- extra credit -- assuming that the Prius is going to be used for overnight camping (i.e. sleep in the vehicle) are there any other things to consider from an electrical perspective (not exhaust perspective, whether camping is a good idea, etc.)

    Thanks!!
     
    #1 Johnny Cakes, Jan 18, 2017
  2. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
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    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    sounds right. camping is a great idea. all the best!(y)
     
    #2 bisco, Jan 18, 2017
  3. JimboPalmer

    JimboPalmer Tsar of all the Rushers

    Joined:
    Apr 14, 2009
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    Location:
    Greenwood MS USA
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    1. The 12v battery is only charged by the HV battery.
    The 12 volt battery is only charged by the inverter. The inverter may be getting power from the HV Battery or the Motor/Generators.
    2. The 12v battery is never charged by the ICE
    True
    3. The HV battery is only charged by the ICE (and regenerative braking)
    True, via the M/Gs. (in the PHEV, line current also charges the HV Battery, but lets ignore that)
    4. Assuming the car is in READY mode and PARK, the 12 volt battery should never loose its charge (assuming the ICE can self-start -- i.e. gas in the tank).
    True
    5. Likewise, assuming the car is in READY mode and PARK, the HV battery will always be kept charged.
    True, although it cycles it's charge, so it may only have 2 bars
    6. The A/C runs solely off the HV battery.
    The A/C compressor runs off the inverter, which may be charged by the HV Battery or the M/Gs. The rest of the A/C is 12 volt.
    7. The various electrical accessories (e.g. USB port, 12v cigarette) run solely off the 12v battery.
    They run off the 12 system which will be battery powered when not in Ready and Inverter powered when Ready.

    Nothing is directly powered by the HV Battery but the inverter, Both M/Gs are AC, as is the A/C compressor. All the DC load is nominally 12 volts.

    This is plodding but clear.
     
    #3 JimboPalmer, Jan 18, 2017
    Last edited: Jan 18, 2017
    mrbigh and SnT08Prius like this.
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