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12v battery health observation

Discussion in 'Gen 4 Prius Technical Discussion' started by Elt31987, Apr 13, 2020.

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  1. CooCooCaChoo

    CooCooCaChoo Senior Member

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    Not talking AGM because AGM isn't the OEM on Prius. Flooded lead acid is.
     
    #21 CooCooCaChoo, Apr 15, 2020
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  2. sam spade 2

    sam spade 2 Senior Member

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    Only very recently, IIRC.
    For the first 10 years or so the battery was "in cabin" and IS an AGM.
     
    #22 sam spade 2, Apr 16, 2020
  3. Mendel Leisk

    Mendel Leisk EGR Fanatic

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    I was idly wondering how you'd bounce back on that one, lol.
     
    #23 Mendel Leisk, Apr 16, 2020
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  4. CooCooCaChoo

    CooCooCaChoo Senior Member

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    This is the 4th Gen section of the forums though ...
     
    #24 CooCooCaChoo, Apr 17, 2020
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  5. sam spade 2

    sam spade 2 Senior Member

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    So do ALL 4th Gen models have the old style wet cell batteries as OEM ?

    Regardless, when the original is changed out an AGM probably still is a better choice.
     
    #25 sam spade 2, Apr 17, 2020
  6. Fester

    Fester Active Member

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    As long as my Aux Battery "Health" is concerned, if my "nominal" readings of current, voltage, with consideration of ambient temp. via the ScanGauge, deviate significantly from what I consider normal (and yes I watch, just out of "Techie" habit) it will be time to take a closer look. If after a couple of years more, which places the battery over 4 years of age, statistically I'd replace the battery after satisfying myself that the Charge system is operating normally. If an academic exercise is required, there is of course the option of direct connecting a (Calibrated and NIST Traceable) Datalogger directly to the battery and reading out to the ninth decimal place voltage, current and temperature. However given that I passed the age well noted in a certain Beatles Song, I am able to place this in its proper perspective, given the current state of the planet...:rolleyes:
     
    #26 Fester, Apr 17, 2020
  7. sam spade 2

    sam spade 2 Senior Member

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    K.I.S.S.
    (y)
     
    #27 sam spade 2, Apr 18, 2020
  8. jerrymildred

    jerrymildred Senior Member

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    See post #2 in this thread. The professor will explain a lot.
     
    #28 jerrymildred, Apr 18, 2020
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  9. Elt31987

    Elt31987 Active Member

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    So i took it for a long enough drive, turned the car off, popped the hood and came back 9 hours later without the key in pocket and reran the test. So looks like it probably only charges up to about 66%. So i guess ill just keep my handheld jumper packet in the glovebox for when it decides its time to go
     

    Attached Files:

    #29 Elt31987, Apr 20, 2020
  10. sam spade 2

    sam spade 2 Senior Member

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    I would be shopping for a new battery NOW........because I don't like unexpected "adventures".

    Even if your car did come with a conventional wet cell battery from the factory, an AGM replacement would still be a better choice. Might last twice as long.
     
    #30 sam spade 2, Apr 20, 2020
  11. Elt31987

    Elt31987 Active Member

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    I dont think anyone has found an H4 AGM battery. There seem to be around 4-5 Wet H4 batteries with the Champion at Pepboys being the cheapest with the longest warranty. 99.74 3 year replacement
     
    #31 Elt31987, Apr 20, 2020
  12. Mendel Leisk

    Mendel Leisk EGR Fanatic

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    I'm really reluctant to cross the infamous Sam Spade 2, but c'mon...
     
    #32 Mendel Leisk, Apr 20, 2020
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  13. alanclarkeau

    alanclarkeau Senior Member

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    TOYOTA's specification isn't for an AGM.
     
    #33 alanclarkeau, Apr 20, 2020
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  14. Elt31987

    Elt31987 Active Member

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    I'd be curious what another Gen 4 owners battery shows for voltage after about 9 hours. Im wondering if the car doesn't fully charge the battery to extend its life. I could also test this by using my
    BLACK+DECKER BM3B Fully Automatic 6V/12V Battery Charger/Maintainer
    to see if it will fully charge it. Then come back 9 hours later and rerun the test. Im assuming its safe to connect this directly to the positive and a ground point on the vehicle?
     
    #34 Elt31987, Apr 20, 2020
  15. bisco

    bisco cookie crumbler

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    you can connect it to + and - then turn on the charger
     
    #35 bisco, Apr 20, 2020
    Last edited: Apr 20, 2020
  16. Elt31987

    Elt31987 Active Member

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    Alright, i know newer vehicles have sensors on the cables and everything else possible so didn't know if it was no longer suggested to connected straight to the battery with the car terminals still connected.
     
    #36 Elt31987, Apr 20, 2020
  17. bisco

    bisco cookie crumbler

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    12.4v isn't horrible, but it's more important to know what it drops to as load is applied.

    personally, i'd hang on to it, and keep the jump pack at the ready
     
    #37 bisco, Apr 20, 2020
  18. bisco

    bisco cookie crumbler

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    i would also be curious to know what others are seeing. i'd be surprised if a healthybattery wasn't held around 12.6 or more.
     
    #38 bisco, Apr 20, 2020
  19. Salamander_King

    Salamander_King Senior Member

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    Just a word of caution. Don't rely on a single battery tester reading for accurate measurement of the battery voltage. Yesterday, I took measurements of my PRIME's 12v battery with three devices.

    Craftsman model 82141 digital multimeter: 12.41v
    Quicklynks Battery Monitor II: 12.56v
    Ancel BA101 battery tester: 12.63v

    The difference is as much as +/- 0.22v among those three devices. I don't know which one is the most accurate.

    Screenshot 2020-04-20 at 2.45.26 PM.png
     
    #39 Salamander_King, Apr 20, 2020
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  20. Mendel Leisk

    Mendel Leisk EGR Fanatic

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    Geez, you're armed to the teeth"! (y)
     
    #40 Mendel Leisk, Apr 20, 2020
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