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Eating aux batteries...

Discussion in 'Generation 1 Prius Discussion' started by Gen1guy, Sep 23, 2012.

  1. Gen1guy

    Gen1guy New Member

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    So I've had 2 yellow top batteries in my car(big ones not Prius ones) and it seems the car is destroying them... After some scanner driving it appears the car Never stops feeding this thing 13.63 volts even with no load... Both batteries came from other uses but tested fine on my "toast" meter...theories?


    Have fun !

    Eric
     
    #1 Gen1guy, Sep 23, 2012
  2. jdenenberg

    jdenenberg EE Professor

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    Do you take a lot of short trips? That can result in a low SOC of the 12v and that will quickly kill any lead acid battery (sulfate crystals on the lead plates). Using a Battery Minder - BatteryMINDer Plus 12 Volt 1.3 Amp Battery Charger: BatteryMart.com to maintain charge and de-sulfate the plates will correct this problem.

    JeffD
     
    #2 jdenenberg, Sep 23, 2012
  3. jdcollins5

    jdcollins5 Senior Member

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    First, 13.6V charging is pretty typical for Gen II. Second, I think after two used batteries I would break down and buy a new battery.
     
    #3 jdcollins5, Sep 23, 2012
  4. Gen1guy

    Gen1guy New Member

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    My only qualm is the batteries are A one year old B just took a 2200 mile boon docking trip in our motorhome with no hookups and just driving and solar to keep em up... both being used as house /emergency start batteries issue free...
     
    #4 Gen1guy, Sep 23, 2012
  5. John H

    John H Senior Member

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    maybe OptimaJim can help out.

    I think he will advise to cycle the battery, using a string of 12v christmas tree lights overnight and then charging it back to full capacity.
     
    #5 John H, Sep 23, 2012
  6. joedirte

    joedirte Member

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    "Other uses", you mean you took a regular lead acid battery and put it on a Prius? If you did that, the problem is the car is designed to use an AGM battery because it never uses the 12V except for keeping the keyless entry and power locks and stuff working, and then when you put the key it, it allows booting up the computers and relays to the high voltage battery. Then the highvoltage uses a DC-DC to keep everything at 13.5 to 13.9V.

    So a regular car battery is used to like 80A to start the motor, then it sits at 14V or more, but the AGM is designed for low current for a long long time and can be constantly charged. unlike a lead acid traditional battery which I assume is plating and starting to bulge?

    You could also pull the fuse for keyless entry if they are AGM going bad.. But that is a hassle.
     
    #6 joedirte, Sep 24, 2012
  7. Gen1guy

    Gen1guy New Member

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    They are not traditional lead acid they are optima yellow tops exactly the same as the kit ones for prii only I used full size not the overpriced tiny one that fits into the hole...I use traditional AGMs for my outbuildings solar array , I just find the optima batteries handle crank and deep cycling well in my vehicles ... Lead acid batteries suck period. If I had the funding everything I own would be LiPo...


    Have fun !

    Eric
     
    #7 Gen1guy, Sep 24, 2012
  8. joedirte

    joedirte Member

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    Are you leaving the car for more than 3 days without going to READY? Or maybe you are doing something in accessory for long periods. Have you checked the voltage when you start in the morning or the current draw when key is out of ignition?
     
    #8 joedirte, Sep 26, 2012
  9. bwilson4web

    bwilson4web BMW i3 and Model 3

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    Due to the trunk light, this is a little tricky.

    Bob Wilson
     
    #9 bwilson4web, Sep 26, 2012
    Gen1guy likes this.
  10. Gen1guy

    Gen1guy New Member

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    Went to Toyota and forked out $256 for a Oem aux battery...drama followed on the drive home but that's another post :)


    Have fun !

    Eric
     
    #10 Gen1guy, Oct 9, 2012
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