1. Attachments are working again! Check out this thread for more details and to report any other bugs.

What Are Normal Voltage and Ohm Readings on a Prius 12v Battery?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by PriusPersonThing, Aug 31, 2022.

Tags:
  1. PriusPersonThing

    PriusPersonThing New Member

    Joined:
    Aug 13, 2022
    4
    0
    0
    Location:
    US
    Vehicle:
    2013 Prius
    Model:
    III
    As the title suggests, I was wondering if anyone knows the proper voltage for a Prius 12v battery.

    My Prius is a 2013 Toyota Prius Five 1.8L MFI HEV DOHC 4cyl. I've heard that anything above 12 volts is pretty solid. Secondly, I'd like to know the proper resistance level (I think it's Ohms) for the battery connecters. I really hope there isn't a lack of resistance in the battery connectors, because that means there's a wiring problem that's sucking the 12v dry.

    Any advice
     
    #1 PriusPersonThing, Aug 31, 2022
  2. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    108,036
    49,113
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    12.7 with everything off is probably average. but more importantly is how far it drops under load so that enough voltage gets to the ecu's and relays to boot up.
    you can get a free load test at many auto parts stores
     
    #2 bisco, Sep 2, 2022
    Mendel Leisk likes this.
  3. rjparker

    rjparker Tu Humilde Sirviente

    Joined:
    Jun 6, 2008
    7,688
    4,510
    7
    Location:
    Texas Hill Country
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    Resistance in the 12v battery terminals is not an issue that could "suck a battery dry". Excessive parasitic amp draw when the car is off can be an issue that can drain the battery. Typically a Prius parasitic draw is around 25 ma (thousands of an amp) within 10-45 minutes after shutdown. When it is 50 ma the battery will last half the time before it is discharged enough to not Ready the car. If it was 500 ma the battery may discharge in a day.
     
    #3 rjparker, Sep 2, 2022
  4. Grit

    Grit Senior Member

    Joined:
    Aug 22, 2017
    6,117
    4,041
    1
    Location:
    Wilkes Land
    Vehicle:
    2012 Prius
    Model:
    Four
    Resistance is the efficiency of energy transmission. Troubleshoot for parasitic drain. If you have no parasitic drain, no matter how much resistance present, battery won’t run down or be drained one iota.
     
    #4 Grit, Sep 3, 2022
  5. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    108,036
    49,113
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    get a borg battery: 'resistance is futile'
     
    #5 bisco, Sep 3, 2022
(You must log in or sign up to post here.)