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12v battery terminals fragile?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Terrell, Jun 15, 2013.

  1. Terrell

    Terrell Old-Timer

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    What is the purpose of all the plastic at the 12v positive battery post? And the loop at the negative post? Is it to support the cables, and keep vibrations away from the battery posts? Are these posts so fragile? What's the purpose of these plastic parts and the loop on the negative end?

    I ask, because it the posts are really very fragile, then we probably should not be hanging additional cables off the battery posts for an inverter? What will happen if we do?

    Does vibration cause the battery eventually to leak gasses around the posts? Since this battery is enclosed inside, this could eventually lead to problems if this is the case.

    The battery is vented to the outside, by the battery cover and hose which vents under the car. If the posts are fragile, wouldn't this venting system take care of things?

    Does anyone know why Toyota made such elaborate plastic parts on the positive battery post? (besides holding the 140A fuse)
    BatteryPosts.jpg
     
  2. gliderman

    gliderman Active Member

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    High Quality engineering and construction!
     
    dogfriend and WE0H like this.
  3. The Electric Me

    The Electric Me Go Speed Go!

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    Mr. McGuire: I just want to say one word to you. Just one word.
    Benjamin: Yes, sir.
    Mr. McGuire: Are you listening?
    Benjamin: Yes, I am.
    Mr. McGuire: Plastics.
    Benjamin: Exactly how do you mean?

    I personally think "Plastic" get's a bad rap. It's not by definition necessarily "Fragile", infact it can be very durable. In the case of a battery post or battery post cover- plastic is a good non-corrosive choice.
     
  4. El Dobro

    El Dobro A Member

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    That's fairly common on a lot of cars nowadays.
     
  5. David Beale

    David Beale Senior Member

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    Much of the plastic you ask about is there to hold the red cover. The red cover is there to prevent users in the US from suing due to electrical fires. ;) The rest is to hold the 150 A fuse, which should be in "free air" to prevent overheating.
    The loop in the negative or ground lead is there to absorb stress. The cables are heavy. As the vehicle is shocked (physical not electrical) they move. The loop absorbs that, preventing the ground bolt from loosening.
    Proper installation of heavy cables to the battery would keep the cables from rubbing on the body under physical shock and ensure they do not transfer physical loads (vibration) on the terminals. Vibration will cause corrosion. Corrosion is the enemy in high current DC!
     
  6. Terrell

    Terrell Old-Timer

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    When I mention "fragile" it has to do not with the plastic parts, but the battery posts themselves. Is the plastic there to reduce vibrations to the battery posts? Are the battery posts in need of protection from vibration?

    Thanks, David, that makes sense. (The fuse on the 2010 is 140A)
     
  7. gliderman

    gliderman Active Member

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    Doesnt the second part answer the first part? ^^^^^^^^^
     
  8. David Beale

    David Beale Senior Member

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    If you ever work a "retail" job you will experience the "great unwashed public".

    You KNOW someone will remove the floor panels to gain more carrying space. Then they will put some metal item over the battery. The resulting fire would be Toyota's fault! Hence the plastic overkill.
     
  9. css28

    css28 Senior Member

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    I can remember when VW's had a plastic cover over the "+" terminal to keep it from contacting the springs in the rear seat cushion.
     
  10. ftl

    ftl Explicator

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    ^^
    Heated seat option?
     
  11. gliderman

    gliderman Active Member

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    Most vehicles I have owned in the last 20 or so years have covers over the terminals.
     
  12. tach18k

    tach18k Member

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    One reason is over time the cable could have problems, and thus need to be shorten or a new connector on the end, it is always nice to have some spare cable to make things fit correctly
     
  13. El Dobro

    El Dobro A Member

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    Yep, when you sat on that back seat and the terminal cover was missing, it got hot.