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Please help explain (with pix?) how to disconnect 12v battery

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by mrken, Sep 16, 2010.

  1. mrken

    mrken Junior Member

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    I'm going on leave for a year and leaving my 05 prius in a friend's garage for the year. I was in a bit of a rush before leaving and decided it was easier to ask him to drive it around the block every couple of weeks rather than do anything special to the car for storage (other than oil change and gas fill). But now I think I should have him disconnect the 12v and not touch it. (Some are saying such seldom use is actually worse than no use; plus I'm going to let the registration lapse.) I've done a number of searches for how to disconnect the 12v battery but can't find anything that I could understand (including /forums/gen-ii-prius-care-maintenance-troubleshooting/70071-how-disconnect-12v-battery on which I couldn't even really tell where the battery is in the trunk). But if I'm going to ask him to do it for me, it's going to have to be ABSOLUTELY basic, with step by step pictures. (This guy didn't know how to jump a regular car, which I found surprising since he's from Edmonton, Alberta where I thought everyone would know how to jump a car.)

    Thanks for any help you can offer; I'd rather not return to a dead 12v.

    Mrken

    p.s. I know the other option is to get a battery tender, but I wouldn't know which one is right and then I'd STILL have to ask him to install it, and I'd be asking to use his electricity for the whole year too - so I think it's just better to disconnect. He knows how to use the manual key for entry if necessary.
     
    #1 mrken, Sep 16, 2010
  2. Rokeby

    Rokeby Member

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    #2 Rokeby, Sep 16, 2010
  3. adamace1

    adamace1 Senior Member

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    How long can the HV battery sit before damage is done? I think Toyota says to drive the car at least once a month or something like that. I would ask him to drive it at least 20 miles at a time and do it at least once a month. but thats just me
     
    #3 adamace1, Sep 16, 2010
  4. krg03

    krg03 Not expert, just experienced

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    LOTS of warnings about waiting 90 seconds and not setting off the air bags.

    REMOVAL​
    1. DISCONNECT CABLE FROM NEGATIVE BATTERY
    TERMINAL
    CAUTION:
    Wait at least 90 seconds after disconnecting the
    cable from the negative (-) battery terminal to​
    prevent airbag and seat belt pretensioner activation.
     
    #4 krg03, Sep 16, 2010
  5. Patrick Wong

    Patrick Wong DIY Enthusiast

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    That warning is applicable only if you want to mess with the SRS system after disconnecting the 12V battery.

    Good to see that the OP is already planning to replace the engine oil and oil filter. In addition I suggest that the tires should be inflated to the maximum cold pressure per the sidewall markings (usually 44 psi) and then force-charge the traction battery up to 7 or 8 green bars before putting the car in storage.
     
    #5 Patrick Wong, Sep 16, 2010
  6. 2009Prius

    2009Prius A Wimpy DIYer

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    Would removing the dome fuse be equivalent? Just wondering.
     
    #6 2009Prius, Sep 17, 2010
  7. Patrick Wong

    Patrick Wong DIY Enthusiast

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    The DOME fuse is removed before the Prius is shipped across the Pacific. However I don't know that this is equivalent to disconnecting the 12V battery.

    If you care to know, you would have to hook up an ammeter to read 12V battery current, pull the DOME fuse, and see whether any current drain continues or not.
     
    #7 Patrick Wong, Sep 17, 2010
    1 person likes this.
  8. krg03

    krg03 Not expert, just experienced

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    From the wiring diagram it appears that the IGNITION IGN 7.5a fuse powers the srs system. Makes sense if your car is hit in the parking lot it doesn't deploy.

    All recommendions state remove the negative battery after 90 seconds. The dome does not power the srs system.

    Page 301
    http://www.selidori.com/tech/prius/DOC/Tech2006/Wiring Diagrams.pdf
     
    #8 krg03, Sep 18, 2010
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