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Battery Testing and Trickle Charging

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Kent10, Mar 27, 2022.

  1. Kent10

    Kent10 Junior Member

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    We have a 2007 and a 2015 Prius. We don’t drive them long distances as much as we used to and so I would like to trickle charge the batteries. The problem for me is that the batteries are in the back and difficult to access.


    I tried testing the quality of the batteries with a battery tester (Konnwei KW208). Am I able to do this from the front using the plus terminal in the fuse box? I tried it and it doesn’t work. Perhaps I need a better location to attach the negative clamp but I did try various places.


    Am I able to trickle charge the battery from the front using the plus terminal in the fuse box? I have a Noco Genius 5 but I am concerned 5 amps is too much for the Prius battery. Should I get a Noco Genius 2? They are good for up to 40Ah batteries but at least one of my Prius batteries is rated at 45Ah so maybe it won’t work? Is there anything better?


    Thanks very much, Kent
     
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  2. JC91006

    JC91006 Senior Member

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    You can trickle charge using the front. For the negative, use the strut bolt. That’s right next to the fuse box
     
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  3. dolj

    dolj Senior Member

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    And yes, the Noco Genius 5 will be perfectly fine for both Prii.
     
  4. Kent10

    Kent10 Junior Member

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    Thanks JC91006 and dolj. Appreciate your help!
     
  5. BuyJapanese

    BuyJapanese Member

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    I support trickle charging (and jumping) through the front.

    It will be slower, but it will work.
     
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  6. dolj

    dolj Senior Member

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    Slower than what? Charging directly on the battery?
     
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  7. edthefox5

    edthefox5 Senior Member

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    Slower than what?

    trickled my 07 from the front for years and years.

    But the 12 V is not the problem. You let the 07 sit it will kill the hybrid battery not so much for the 2015.

    Plenty of idiots out there that will still buy a G2.

    Get. Rid. Of. It.

    Read all the posts here about all the dead hybrid battery’s on a G2. It’s not if it’s when. And when is always at the worst possible time.
     
  8. sam spade 2

    sam spade 2 Senior Member

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    Well since nobody else said it..............

    A smart, tender type charger is NOT a "trickle" charger.
    A trickle charger is a specific kind of dumb charger that will keep charging the battery whether it needs it or not and can do some damage over long periods of time.
    Referring to a smart charger as a trickle charger really is giving out bad information.

    Then......the max. capacity of a smart charger is really not important since it will adjust down to the charging rate that is needed at the time.
     
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  9. BuyJapanese

    BuyJapanese Member

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    Yes. 1% slower, 10%, I don’t know but there is SOME added resistance when you’re charging the battery remotely like that. This is not a reason not to do it, but just seems useful to acknowledge that.
     
  10. sam spade 2

    sam spade 2 Senior Member

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    While that sounds logical it really is NOT true because the difference is so small.
     
  11. alftoy

    alftoy Senior Member

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    Noco Genius is fine, its a smart charger, adjusts automatically. Pic shows attachment points for charger. Ring terminal connections on each vehicle allows you to move the charger between both vehicles.

    Noco Ring Terminals for Genius 5 are $7.48 each, reg $19.95 Amazon
     

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  12. alftoy

    alftoy Senior Member

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    Whaa, Ed having a bad day?
     
  13. Kent10

    Kent10 Junior Member

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    Thanks all. Very helpful. The 2007 has a new Hybrid battery. It died quite suddenly but not from lack of driving. Overall, it has been a great car for us with over 200,000 miles on it. We almost sold it and bought the 2015 but then decided to keep the 2007 after getting the new Hybrid battery. It works perfectly now.
     
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