12 volt battery issue

Discussion in 'Gen 3 Prius Technical Discussion' started by Hybrid3000, Aug 27, 2019.

  1. Hybrid3000

    Hybrid3000 Junior Member

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    Jump pack should be here tomorrow, hopefully. And thank you for all your detailed responses. I'll update after the jump, hopefully that's all it needs.
     
  2. Hybrid3000

    Hybrid3000 Junior Member

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    Got the jump pack, unfortunately the negative clamps has barely any reach, can't seem to figure out where I would put it? Any ideas? Can it be any metallic point?
     
  3. Ed Beaty

    Ed Beaty Active Member

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    Try this for a ground point:

    2010Prius EngBayGrnd.jpg

    Also this, from the always useful Mendel Leisk:

    "If you have a multimeter you can sus out good ground points. Easiest is if it's got a continuity scale with audio feedback: beeps when you've made a circuit. Clamp one lead to a know ground, then go around touching possible ground points with the other lead."

    Finally: It might also be possible to peel the two leads on the jump pack apart in order to get to more locations.
     
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  4. Mendel Leisk

    Mendel Leisk Senior Member

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    Yes. It may be recoverable, but you'd need to see where it's at, and attempt charging. One question though: how old is this battery? 4~5 years old, I would just replace. If it's the original battery, no question: it's overdue for replacement.

    It's ok to charge without removal. Just be careful with connection, don't reverse the connection.

    You've got to think through: what your priorities are:

    1. A jumpstart pack, or jumper cables and a second vehicle, will get the car running, good for emergency use, when you're stuck somewhere, absolutely have to move it first. When ever using jumper cables and a second vehicle, connect the cables in this order:

    a) positive cable to positive on dead car.
    b) positive cable to positive on live car.
    c) negative cable to negative on live car.
    d) negative cable to ground on dead car.

    Disconnect in opposite order.

    Never: connect positive and negative cables just at one car, with the other ends loose. If the other ends touch together, you've just shorted out the battery.


    A screen grab from Owner's Manual (starts at page 543:

    upload_2019-8-30_13-30-47.png
    upload_2019-8-30_13-31-17.png
    upload_2019-8-30_13-31-50.png




    2. A digital multimeter, or better, something like Solar BA9, will give you info about your battery's current state.

    3. A smart charger, one that will initially check if the battery is even viable, then run a multi-stage charging process, and finish off as a trickle charger. 3rd gen, 3~4 amp rated chargers are optimum.

    What I use:

    Clore JNC 660 Jump Pack
    Solar BA5 electronic load tester
    CTEK 4.3 smart charger

    For your immediate issue, the jump pack with short leads, this point will likely be ok too, and is very close to the fuse box:

    upload_2019-8-30_13-22-58.png

    But verify: a multimeter with a continuity mode (or just on a low resistance scale), touch the two points flagged in the above, see if there's continuity between them (low resistance). That'll indicate they're both grounded. I know the one on the left is grounded. I've used it for years. It's screwing directly into the cylinder head.

    Keep in mind though: jumpstarting the car will not completely revive the battery; it's just a stopgap to get the car moved. You still need to test and charge (or replace) the battery.
     
    #24 Mendel Leisk, Aug 30, 2019
    Last edited: Aug 30, 2019
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  5. Hybrid3000

    Hybrid3000 Junior Member

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    Thank you for your detailed response, I thought jumpstarting and then driving for a while would charge up the battery?

    Also, your pictures on where to put the negative clamp were really helpful.

    I got it to finally work, however just one jump did deplete the jump pack, but thankfully worked like a charm.
     
  6. dig4dirt

    dig4dirt MoonGlow

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    Everything good, any dash lights or codes?
     
  7. dig4dirt

    dig4dirt MoonGlow

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    They recommend to charge up the pack when first receiving. Not sure if u did that.
    Def charge it up fully now, and keep it in your Prius.
    Perhaps @Mendel Leisk can post the current recommended 12V replacements
    Im sure you will want to replace that sooner than later.
    However it could last a little bit longer depending on age.
     
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  8. Hybrid3000

    Hybrid3000 Junior Member

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    Everything looks good, no dashlights or anything unusual.

    Definitely going to start looking into replacing the 12v eventually, car started just fine, right away on the second day and today too.

    I'm thinking the battery might not even be the original, maybe the dealer put a new one in? They did say that the last time the car was turned on was about a month ago, when I originally bought it 3 months back. Shouldn't a older battery give in after such a long period of not turning on? Since it started right away on the initial test drive.
     
  9. dig4dirt

    dig4dirt MoonGlow

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    Not an expert here, but I have read countless times that batteries can only take so much stress.
    So after it ages, and those stresses compile (not driving much, so not charged often, short drives)
    (and doors left ajar with interior lights on and drains battery) and also multiple jump starts, etc...
    Then at some point the battery can fail and not take a charge.

    I have been monitoring mine and also have recently been trickle charging the most I can on both
    of my Prius' since I believe both have been jumped due to door ajar etc.

    But with a multimeter, they still both test around 12.5v or so after a full night
    or multiple nights of no use. (also I dont open drivers door before test)