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Drained 12V Battery Makes Prius Go Crazy

Discussion in 'Gen 5 Prius Audio, Electronics and Infotainment' started by Rordon Gamsay, Jul 13, 2024.

  1. Rordon Gamsay

    Rordon Gamsay New Member

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    Just wanted to share this video for when this happens to someone else.

    I just installed a subwoofer in my car and while playing with it and running the A/C in accessory mode, I drained the 12v battery to 7v. The car wouldn't start in ready mode, the dash became glitchy and lit up with several warnings and beeps, the headlights started flashing on and off, and electronics/sensors/brake assist stopped working. It felt like my car had gotten possessed by something.

    Charged the battery back up I can run everything like normal as long as I'm in ready mode.
     
  2. bisco

    bisco cookie crumbler

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    always be in ready mode has been our motto for over 20 years. you should have the battery load tested
     
    Rordon Gamsay likes this.
  3. vvillovv

    vvillovv Senior Member

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    Thinking about it from the 12volts point of view, the Prime is probably not the best choice for carcampiung.
    Not sure about Gen 4 and 5 Prius, either.

    Is it mostly the Primes showing the 12volt drain in Ready mode with the engine off? I'm thinking that is one drawback of the Primes since they can stay in Ready mode so long without having to run the engine. While the Prius will start the engine much sooner than a Prime.

    Any one got the numbers for the Gen 4 and 5 Prius 12volt issue, yet?
    Another question this brings to mind is how many control and sensor modules are in the Gen 5 s?

    I know this is a stretch but, if anyone can figure out how to get the Primes 12 volt to charge while in Ready mode with the engine off, that'd be a nice feature to add to someones app,
    even if we have to pay for it.....
     
    #3 vvillovv, Jul 14, 2024
    Last edited: Jul 14, 2024
  4. soft_r

    soft_r Member

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    That's literally what "READY mode" does. It means the HV is active and can charge the 12v.

    Do you mean ACCESSORY MODE? Where you push the button without pressing the brake? Because accessory mode does not activate the HV.

    I can't think of a single car where anyone should run accessory mode for any notable duration. Hybrid or not.
     
    Brian1954 likes this.
  5. Cc103acs

    Cc103acs New Member

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    I car camped in my RAV4 Prime using the room mode. And, voila, the Prius Prime has a room mode as well. Need to have a camp site with electricity… plug the car in so it charges and also plug your battery tender in to keep the battery topped off. My battery tender is a NOCO Genius 5.
     
    bisco and vvillovv like this.
  6. vvillovv

    vvillovv Senior Member

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    I wasn't sure if I should respond of just let it slide. After all it's hard enough for Prime owners to figure out the car, much less a Prius owner.
    In a Prius, fur sure.
    No, not really, but thanks for your contribution.

    @Cc103acs I'd forgotten about Room mode, I'd only seen it posted here once before without details and only in reference to a Rav. Is that how it works in both the Rav and the Prius Primes, or does the Rav and maybe even the Gen 5 Prius Prime have an actual Room mode setting?
    Prius campers might complain about how much extra work it is to camp in a Prime, ya know needing the outlets and having to plugin just to run the HAVC all night long. -haha-
    Thanks, I wouldn't have thought of that in a million years, I'm usually to busy staying up all night watching what the cars doin in one or another app.
     
    #6 vvillovv, Jul 15, 2024
    Last edited: Jul 15, 2024