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Trickle Charger/Battery Maintainer & Charging Port Under Hood?

Discussion in 'Gen 3 Prius Main Forum' started by Lottamoxie, Apr 15, 2015.

  1. Lottamoxie

    Lottamoxie Member

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    I have a 2010 Prius.

    Just replaced the OEM battery since the 12v died.

    Purchased a 1amp automatic/intelligent trickle charger/battery maintainer since there are stretches of days when I don't drive my car at all and I want to preserve the new battery.

    Supposedly the jump start port located in the fuse box under the hood can be used to charge/maintain the battery. Today I tried it out and connected the red + connector to that port and then connected the black (-) grounding connector to an unpainted metal piece on the car.

    The charger itself was powered on and the light was on, but absolutely no activity was occurring through that charging/jump port. I don't understand why this doesn't work? BTW, the brand I purchased is highly rated and I saw no issues with the trickle charger itself.

    Yes, I know I will need to now try it on the battery itself in the rear compartment, but that will have to wait for a non-rainy day as I don't have a garage or shelter for my car.

    In the meantime... any thoughts on why there was no battery charging occurring when the charger was connected to the port under the hood?
     
  2. AzWxGuy

    AzWxGuy Weather Guy

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    Maybe because the battery is new and doesn't need charging? I have a charger maintainer also, an Optimate 5, which runs the battery through some charging sequences and tests. I would imagine other brands would do the same so you should have seen some activity. I always use the closest upper shock mount bolt for the negative clamp. You might try putting a volt meter on those same connections to see if you can read the battery voltage.
     
  3. Mike500

    Mike500 Senior Member

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    I connected my battery minder maintainer directly to the battery in the rear compartment with the pigtail coming out the back through the battery vent.

    It was an easy setup.
     
  4. Mendel Leisk

    Mendel Leisk Senior Member

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    I'd suspect the charger, since you just got it. There's some status light on it, that should light up when it's charging? Try it on another vehicle?

    One amp is pretty low for charger, 3-4 amps is more the norm. Even at 3-4 amp a charger will take up to 12 hours to bring a battery back up if depleted, so not overkill.

    I charge sporadically with a CTEK3300, at the fuse box with alligator clips, works fine.

    Typically once in a battery's life I'll pull it out of the car, clean the posts and cable clamps, charge it directly. It's good as a rehearsal for when you swap battery too.
     
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  5. bisco

    bisco cookie crumbler

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    the post only has metal on one side, so make sure you have a good connection.

    why is the car on? put a dvm on it, with the car off, so you have an understanding of the connections and a good reading of your battery.
     
  6. Mendel Leisk

    Mendel Leisk Senior Member

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    Are you misreading? OP said his charger was on, but I don't see anything about the car being on.
     
  7. bisco

    bisco cookie crumbler

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    whoops.:oops:
     
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  8. David Beale

    David Beale Senior Member

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    Yes, if the car was on the internal charger would probably put out more voltage than the maintainer, so it would do nothing. The Prius runs at around 14V, and most maintainers try to say below that (to avoid overcharging during the long periods they are connected).

    Pearl and Pearl S both have been charge maintained from the boost point over the years.

    Turn car off, open hood, open fusebox, connect maintainer, plug in the maintainer. Watch the "entertainment lights" on the maintainer.

    I replaced the large clips with smaller ones with insulated "hoods" over them. Connects easier and gives me a bit of piece of mind.
     
  9. Mendel Leisk

    Mendel Leisk Senior Member

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    The Owners Manual says something about disconnecting and removing the battery from the car, to charge it. But seems like they're lawyers put that one in. You DO want to be real careful to not reverse the leads.
     
  10. Lottamoxie

    Lottamoxie Member

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    - I'm a she, not a he.

    - It's not required to remove the battery to 'maintain it' via trickle charging. This is a small battery maintainer, not really intended to bring a dead battery back to life from total discharge, though I suppose if one had enough time (days) it perhaps could. It's really meant to maintain the battery to avoid discharging from being idle over days/weeks or discharging from only taking short drives.

    - I don't have another vehicle to test the charger/maintainer on, this is it.

    - I don't have a battery volt meter. I guess I could pop in to my local auto zone and get the guys to test the battery through the fuse port just to see what it shows and if that port under the hood is fine.

    - There are 4 lights on this particular battery trickle charger/maintainer:

    1. Power (meaning the trickle charger is plugged in and 120v power is reaching the charger)
    2. Charging (meaning just what it says...there is active charging going on as the wires are hooked up)
    3. Full (meaning battery is fully charged)
    4. Fault (meaning there is a problem and charging is not occurring).
    Yes, the Power light comes on and stays on when plugged in. That means 120v power is connected and so far so good.

    I get no other lights.

    Now, it's a brand new battery I have, less than a week old, so as suggested above, maybe there is nothing to charge even in a trickle state, but one would think the battery 'full' light would come on?

    Still raining here so again, I can't do any more tests until the rain stops as my car sits outside because I don't have a garage or carport.
    [​IMG]
     
  11. Mike500

    Mike500 Senior Member

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    I would use the direct connector to make a direct connection to the battery under the right rear panel where the battery is located. The terminal furthest back is the NEGATIVE.

    You need a couple of 10mm wrenches.

    Just disconnect the negative cable first an lay it to the side.

    Remove the 10mm nut from the positive cable clamp. Place the ring terminal with the red marked insulator on the stud from which you removed the nut, replace the nun and tighten it a half a turn after contact. Put the NEGATIVE clamp back on and do the same with the BLACK marked terminal.

    Replace all of the trunk fittings with the dual connector exposed in the hatch area.

    Now, all you have to do is to open the hatch to connect the maintainer. The hatch gasket will allow the cord to go through the lower edge of the hath area while still keeping out the rain.

    A slow micro charge of three to four days is BEST for maintaining the battery.

    Quick high amperage charge rates shorten battery life.
     
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  12. David Beale

    David Beale Senior Member

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    It is most likely that the clip wasn't contacting the "boost point" plate. It's only metal on one side. Notice that the wire on the clip only connects one side of the clip, relying on the "hinge" to transfer power to the other side of the clip. Make sure the clip is attached such that the wire is on the "front part" of the boost point. That's where the metal is.
     
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  13. bisco

    bisco cookie crumbler

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    i would think either the charging light or the full lite should be on. mine is red for charging and green for full, and it's always one or the other.

    did you try my suggestion in post #5? the post only has metal on one side.
     
  14. Easy Rider 2

    Easy Rider 2 Senior Member

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    Yes absolutely, the charger is no longer functional.

    This assumes, of course, that both charger clamps really ARE making good contact where they are supposed to be.
    Since without being connected to anything, only the power light is ON and that is normal.
    The ground connection point is often problematic.

    When you DO make the proper contacts, the charging light usually comes on for a few seconds even on a fully charged battery before the "charged" light comes on.

    P.S. You can get a decent meter for $10 or less. Good thing to have.
     
  15. Mendel Leisk

    Mendel Leisk Senior Member

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    Most alligator clamps will make the circuit in either orientation. Some won't tho.