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Auto charge mode for usb devices on 12v.

Discussion in 'Gen 3 Prius Technical Discussion' started by ickk, Oct 20, 2018.

  1. ickk

    ickk New Member

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    this is my first post. I've read quite a bit about the battery charging on the Prius, and how it will start the engine to recharge the battery when its low. Which vehicle mode is required for this? My goal is mainly to determine if I can safely run accessories like USB chargers or a 100W inverter with the prius on overnight.

    For example, I want to leave an old phone plugged in constantly charging that has tracking software for the vehicle. However I do not wish to risk a dead battery on the car (or the phone), how can I ensure the engine will charge the battery when its low, without driving it?
     
  2. FuelMiser

    FuelMiser Senior Member

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    You must be in Ready mode for the charging system to work.
     
  3. sam spade 2

    sam spade 2 Senior Member

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    I think you worry WAY too much.

    The charger for the phone won't draw that much current. And when the phone is charged up, which should be most of the time, it should draw close to nothing.

    Why not power the phone charger from a "switched" 12 V source so that it would be off when the car is off ??
    I think most models have the "cigarette lighter" style plug switched like that.

    AND.....if you are worrying about having the car stolen, leaving it sit there "running" would make it really easy to steal.
     
    Grit likes this.
  4. ickk

    ickk New Member

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    Thank you I notice that now when I leave it running. It was on 2 bars a really long time so I was confused on whether the car was going to charge, but eventually it started. I also turned my lights off so it doesnt drain the battery.

    Its one thing to have your car stolen, its another to have your car stolen with Cerberus on a device inside the car monitoring the criminal. My phone has been stolen by opportunists, but I've always had success tracking them back to their house or work. I'd like to setup an auxiliary battery so the phone is always online but for now I just needed to setup a usb until I can get a few lithium pouches.
     
  5. PriusCamper

    PriusCamper Senior Member

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    No need for an extra battery, power inverter or lithium pouches. Simply use your existing 12v or better yet, upgrade to the highest quality 12v wheelchair/backup power supply battery that will fit in the 12 volt battery space (55 amp hour or higher) and run a wire direct from yr 12v battery to a 12v phone charger. These phone chargers are very inexpensive via ebay or amazon and don't draw enough power to drain your battery for a few days or longer. And for times longer than a few days, spend $10 on a 12v trickle charger that you plug in to a wall on occasion to keep 12v battery fully charged and you'll be good to go.
     
  6. ickk

    ickk New Member

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    I see what you mean, that would definitely work around the vehicle controls and allow the phone to always charge. I think this would be better if the prius battery was paired with another 12v battery for charging, but have the load wired to only drain an aux battery. This way it works like you said, but if your car gets towed or you dont drive it for a while - it wont have a dead battery when you come back.

    Your idea would definitely work but I dont always have access to a 110v outlet if my built in dies, although I do I have jumper pack.
     
  7. sam spade 2

    sam spade 2 Senior Member

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    OK let me try to re-phrase:
    I think you increase the odds of HAVING it stolen at all about 1000% if you leave it "running".

    And the 12 V battery in the car should keep a normal cell phone running probably for a week and still start the car unless maybe the app you are running is REALLY power hungry.

    If it is, you can buy a portable jump pack pretty cheap these days. Many of them have a USB charging port built in. You could plug it in to recharge when you are actually driving and then use it to run your "theft tracker cell phone" when not driving.

    I think what you propose is......highly unwise......to put it nicely.
     
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  8. PriusCamper

    PriusCamper Senior Member

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    Yea... Get one of those portable jump packs with USB and keep it as an entirely separate system. Based on where you're at with what you're doing with all this, you're probably better off leaving the car alone and just having a separate set up.