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Going away, how to prevent battery discharge?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Gilbert, Mar 11, 2008.

  1. Gilbert

    Gilbert Member

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    Heya, In a couple of months im gonna go on vacations, and i will leave the car on the airport. Ive read somewhere that people have gone for a while, then upon returning to their car, it wont start up. What do i need to do to avoid my battery from discharging while im away. The away time is around 2 weeks. i have a 08 touring pkg5. thanks in advanced
     
  2. hobbit

    hobbit Senior Member

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    Push in that little "key" button under the steering column,
    and make sure none of the lights are on and the doors are shut
    firmly. Should be good for 2 weeks.
    .
    _H*
     
  3. birdsquared

    birdsquared New Member

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    How long is the Prius "good for" with this set up? (SKS system off, all doors closed and no lights on)? 3 weeks? 4? At what length of time should I be getting a neighbour to look after the car battery by starting it up - and what is the best methodology for that - start up and drive a bit, or simply allow the hybrid battery to 'refill' the 12V?

    Thanks.
     
  4. Patrick Wong

    Patrick Wong DIY Enthusiast

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    TSB PG007-03 suggests the 12V battery be disconnected when the car is left more than 10 days. As a practical matter, if your 12V battery is fully charged and in good condition, it should last a month or more under the conditions you described. However, if your car is driven infrequently for short trips primarily, the battery likely is not fully charged.

    For longer trips, if you have a neighbor taking care of your Prius, all that is required is for the Prius to be made READY for 30 minutes, left in Park. There's no need to actually drive the vehicle. If this is done once every 2-3 weeks your batteries should be sufficiently charged so that your car will be ready for your return.
     
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  5. Gilbert

    Gilbert Member

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    But if i DC the battery, then there wont be any alarm active on the car, if someone breaks in?, like break the glass or force open a door or whatever reaons the alarm gets activated for.
     
  6. Patrick Wong

    Patrick Wong DIY Enthusiast

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    That is correct. Your original post said you would be gone for two weeks and you are parking at the airport. No worries as long as your 12V battery is fully charged before your trip.

    Assume that your parasitic battery current is 40 ma. 0.04A x 24 hours/day x 14 days = 13AH. The 12V battery is rated at 32-33AH. Hence, the 12V battery will be drained 40% after two weeks assuming that it started with a full charge and still has full capacity. It is normally considered OK to drain the battery up to 50% of capacity.

    When you see posters complain that their car wouldn't start after two weeks, this is because their battery was old, or it was not fully charged, or they left something on.
     
  7. richard schumacher

    richard schumacher shortbus driver

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    Or they had an old JBL amp, or had some faulty after-market electronics installation.
     
  8. babyrhino

    babyrhino New Member

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    About that "key" button. I've never used it before. I take 2-6 week trips each mid-winter and my '05 Prius(72, 000 miles) always starts when I return to Michigan. However, I plan to be gone for 10 weeks this coming winter and I'm sure I need to take precautions this time. If the button is pushed and I lock the car will the keyless entry still work?
     
  9. seilerts

    seilerts Battery Curmudgeon

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    If you are leaving your car in a safe place but no one is available to start it every couple of weeks, use a charge maintainer such as BatteryMinder. If you are leaving at an airport or out in the open, your best options are disconnecting the battery, or just letting it sulfate and die and having a portable jump starter in the back seat that you can use to get the car started to drive home and install an Optima replacement battery.
     
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  10. 2009Prius

    2009Prius A Wimpy DIYer

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    The "key" button disables the smart key function if pushed in so you will need to use the remote control button on the fob to unlock the car when you come back. Good luck! :)

    +1 on preparing a portable battery jump starter.