Battery gone, how to restart

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by enginestarter, Sep 24, 2020.

  1. enginestarter

    enginestarter Junior Member

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    I got a new car.
    My Prius isn't starting now - hadn't been turned on for 2 weeks.

    What do I need to do to startup?
    I was looking at cheap battery chargers on ebay - but someone said to avoid as the cables looked too thin.

    I wanted to get a battery charger to have as a backup.
    Any recommendations?

    When charging... where do I start?

    I remember when I first tried out the car... I had left sitting on a driveway for 4 months without driving (long story). The car wouldn't start. With the help of someone, we tried charging the front battery. No luck. We then had to resort to charging the batteries at the back in the boot - this was a mission as we couldn't open the boot.

    Thanks.
     
  2. rjparker

    rjparker Senior Member

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    Get a lithium jump starter and put in bypass mode if it won't start from the fuse box. Sometimes your 12v battery is so discharged that it will drag down the voltage from the jump battery. At that point leave it or any jump start on for maybe 5 minutes before you try. Its best to monitor the voltage with any voltmeter in this case.

    As far as your 12v battery, change it if it has reached this state.

    If you want a battery maintainer, consider Battery Tender Jr.




     
    jzchen likes this.
  3. enginestarter

    enginestarter Junior Member

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    Thanks for the reply.
    I'll charge up for 5 minutes before starting.
    I saw a video doing similar - the guy charged... for 5 minutes, then tried to see if he could open the boot.
    Boot opened - he then charged he rear battery.
    Is that a good strategy?

    I didn't want to invest that much into buying a charger to be honest.

    >> As far as your 12v battery, change it if it has reached this state.
    Why would this need to be?

    Let me know.
    Thanks.
     
  4. Stevewoods

    Stevewoods Senior Member

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    You can open the "boot," hatch, from inside the car. It takes a bit of gymnastics.

     
  5. rjparker

    rjparker Senior Member

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    A good battery will easily last two weeks. I have left mine at the airport for three weeks with no issues. Often a deep discharge will damage the 12v battery to the point it won't hold a charge for long. Have it tested after you get it charged up. I don't think charging from the boot matters vs the front. The cable from the front jump point to the back is good sized anyway. This battery does not have a large current requirement to achieve Ready or when opening the hatch. The high voltage battery spins the gas engine. But everything is computerized so the 12v voltage level is important. Lets say it was discharged to 8vdc or lower. Low voltage means computers and networks that are not running.

    I do like the Battery Tender Jr for $25 US or Plus for $49. I use a Jr on a spare Prius battery and it does fine. Its a trickle charger which has multiple protection algorithms to prevent your battery from getting damaged further by fast charging, over charging, constant voltage charging, etc while still providing you the ability to leave it on the car for weeks or months at a time. The battery stays healthy and ready to go. A lot of older or cheaper chargers can't do these things for your 12v battery.
     
    #5 rjparker, Sep 24, 2020
    Last edited: Sep 24, 2020
  6. bisco

    bisco cookie crumbler

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    how old is the battery?
     
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