Does a power inverter connected to the 12v battery drain the battery when it's turned OFF?

Discussion in 'Gen 2 Prius Audio and Electronics' started by wbs887700, Feb 12, 2021.

  1. wbs887700

    wbs887700 Junior Member

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    I keep having to jump start my 2006 Prius and I can't tell if I need a new 12 volt battery, or if the inverter is draining it while it's turned off AND the Prius is off.

    This picture is my 1500 watt pure sine inverter, I drilled holes for the wires and bolted it to the 12-volt battery.

    KIMG1237.JPG KIMG1238.JPG

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  2. ChapmanF

    ChapmanF Senior Member

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    Depends entirely on the inverter. I once had one that did, which was annoying. I had to add a separate relay in the wiring to the battery to really turn it off. Now I have one that doesn't.
     
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  3. ILuvMyPriusToo

    ILuvMyPriusToo Senior Member

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    A cut off on the line in would provide diagnosis and a fix. Did you fuse it down at the battery?
     
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  4. ChapmanF

    ChapmanF Senior Member

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    I've been using a Xantrex Prowatt SW since, which I can vouch is genuinely off when it's off. It's a lot more convenient to just have an inverter with a real "off" than to have to fuss with finding and installing a high-current relay or cutoff.
     
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  5. wbs887700

    wbs887700 Junior Member

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    My inverter does have an off switch. Does that mean it definitely turns it off?
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  6. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    It doesn't mean much. Every inverter manufacturer does it their own way. Some have real off switches that completely interrupt all power. Others just put the inverter into a sleep mode which can still draw some power from the battery.

    You have to read the manual, contact the manufacturer or break out an ammeter and do a real live test.

    Given how small the Prius 12v battery is, it doesn't take much "non-Ready-mode" use to get into trouble.
     
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  7. ChapmanF

    ChapmanF Senior Member

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    The one I had earlier defined "off" as "please chase the outer segments of your LED display around in an animated circle for entertainment." (n)
     
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  8. sam spade 2

    sam spade 2 Senior Member

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    AND......is nobody going to suggest getting the 12 V battery tested ?
    And the charging voltage ?
    Except me ??

    I think the simple fact that an inverter is in use might mean that the battery has been "abused" and is now worn out.

    And I agree that the inverter OFF switch might not turn it completely OFF; a test is necessary.
     
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