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Another newbie: 07 prius, dead battery?

Discussion in 'Newbie Forum' started by Jessie P, Jun 4, 2017.

  1. Jessie P

    Jessie P New Member

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    Location:
    st louis, mo
    Vehicle:
    2007 Prius
    Model:
    N/A
    Hi all! I'm the original owner -- 9 years in -- of my beloved 07 Prius and I've just come across my first serious problem. Without any warning, suddenly, my car won't start.

    I tried a manual start using both key fobs, no luck. No dashboard lights, no engine turnover, both? batteries are apparently dead dead dead. Is this a problem for the dealer or can any hybrid mechanic handle it? (Perhaps I jinxed it -- just yesterday I decided to stop taking my car to the dealer for routine maintenance and started looking into local hybrid repair shops). Is it worth having AAA try to jump start it or should I just have it towed to the shop (any St Louis, MO recommendations?)?

    I don't have a good feeling about this -- am worried that I may have to replace the hybrid battery. But at <40k miles, Isn't my mileage too low to need a new battery? Does anyone have any insight into the problem / suggestions for action? If I do need a new hybrid battery, do you recommend replacing it with a brand new or refurbished battery? I plan to drive the car as long as possible (i.e. until repair costs => blue book value). (Or should I sell it back to the dealer? They keep asking -- its desirable because of the low mileage and because, so far, they've done all the maintenance -- and I keep turning them down because their offers were too low).

    Thanks in advance for all suggestions and advice!
     
  2. RePrius

    RePrius New Member

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    Vehicle:
    2010 Prius
    Model:
    ----USA----
    Relax. Sounds like low voltage battery, 12v. If you have AAA card best way to go. They will confirm 12v battery issue. Then call around for best 12v deal tomorrow.

    FYI, autobeyours in Scottsburg, Indiana if you need anything other than 12v. Steve is a Prius genius!

    Good luck
     
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  3. Jessie P

    Jessie P New Member

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    Vehicle:
    2007 Prius
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    N/A
    Thanks, RePrius! At the risk of sounding completely ignorant (which I am), the 12V is the 'regular' battery in front, right?

    Lol, suddenly feeling a bit overwrought. Thanks for the reassurance.
     
    #3 Jessie P, Jun 4, 2017
    Last edited: Jun 4, 2017
  4. TMR-JWAP

    TMR-JWAP Senior Member

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    Vehicle:
    2007 Prius
    Model:
    Touring
    Jessie,

    Sorry to hear about your problem. My son had a very similar situation a few months ago. It DID end up just being a drained 12v battery (it was only a year old). Your 12v battery is in the trunk, on the passenger side, just in front of the turn signal, under the small floor trim panel/cover and will look like this image.

    Unfortunately, with a dead 12v, you'll be unable to open the hatch. My son and I never were able to determine why his 12v drained, but we were able to power the car up by attaching jumper cables in the engine compartment. We connected the positive cable to the jump connection in the fuse box and we connected the negative to the car chassis. I keep a fully charged full size 12v battery in the garage just for these situations. He was able to start the car normally and the 12v battery recharged enough while he was driving it home. (~25 mile drive). He drove it to USC ~25 miles each way 5 days a week, so it fully charged over a few days. The same battery is still installed in the car and we've never had another problem.
     

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    #4 TMR-JWAP, Jun 4, 2017
    Last edited: Jun 4, 2017
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  5. Jessie P

    Jessie P New Member

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    Location:
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    Vehicle:
    2007 Prius
    Model:
    N/A
    Thanks, TMR-JWAP! So all I have to do is call AAA and have them charge the 12V?

    I am getting a bit confused though -- just how many batteries does the Prius have? There's the regular car battery under the hood, the hybrid battery, the 12v, the traction battery.... or just two batteries with multiple names?
     
  6. TMR-JWAP

    TMR-JWAP Senior Member

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    jessie,

    There are only 2 batteries. The high voltage hybrid battery and the 12v battery. The HV battery is also referred to as the traction battery, hybrid battery, high voltage battery, etc. There is no 12v battery in the front on a 2007.
     
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  7. TMR-JWAP

    TMR-JWAP Senior Member

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    Also, the 12v battery is a bit sensitive to charging and should be limited to 3.5 amps, if I remember correctly. The 12v provides control power for all the systems on the car and power for the auxiliary functions like lights, radio, etc. If the 12v is dead, the HV battery can't do anything because there is no 12v power to operate ECUs, relays, etc. Do you know how old the 12v battery is? If you're at 4+ years old or more, it's probably safest to just replace it.

    If you do get a jump, once the jump cables are connected, you should be able to pretty much immediately power up the car. Once the car is powered up, the HV battery sends power to the inverter in the engine compartment and a portion of that power will be used to supply the 12v system and recharge the 12v battery. Once you power up the car, the jump cables should be removed.
     
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  8. TMR-JWAP

    TMR-JWAP Senior Member

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    Vehicle:
    2007 Prius
    Model:
    Touring
    Here is the step by step from my manual:
    1. Connect (+) jumper cable to the jump start terminal in engine compartment fuse box
    2. Connect (+) jumper cable to (+) terminal on booster battery
    3. Connect (-) jumper cable to (-) terminal on booster battery
    4. Connect (-) jumper cable to chassis ground on vehicle with discharged battery
    5. Depress brake pedal and press"power" button to start the vehicle.

    refer to owners manual for more details.

    It also mentions you may need to have the cables connected for ~5 minutes prior to starting if the 12v is totally depleted.
    It also mentions to disconnect the jump cables in reverse order of connection.

    And don't forget, if you end up having it towed, the transaxle is locked in place when there is no 12v power, so it must be towed with the front wheels off the ground.
     
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  9. Jessie P

    Jessie P New Member

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    N/A
    Thanks! I was rooting around PC and learning about the 12v, but your post was more helpful than piecing the info together. I think my 12v is original to the car, so probably 9 years old, and well overdue for a replacement. I'll call AAA tomorrow to see if they can change it for me if I provide the battery. This is beginning to look simpler and more affordable than I thought. *phew*
     
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  10. Jessie P

    Jessie P New Member

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    Oh wait, I might have had the 12v replaced once about 4-5 years ago. I had forgotten the car died once before and I had AAA tow it to the dealer on a flatbed. You have been so helpful. I am most appreciative!
     
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  11. TMR-JWAP

    TMR-JWAP Senior Member

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    I hope it works out well for you!! Let us know. Hope you have a better second half of the weekend :)
     
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  12. Jessie P

    Jessie P New Member

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    Will do, thank you. And same too you!
     
  13. Jessie P

    Jessie P New Member

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    N/A
    RePrius & TMR-JWAP, thanks so much for your advice. You were spot on. I found a local mechanic who picked the car up from my house and replaced the battery. It's up and running again in great condition. Thanks for your help!
     
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  14. RavMan

    RavMan New Member

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    Location:
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    Vehicle:
    2012 Prius v wagon
    Model:
    IV
    Glad you got it all sorted, having a dead LV battery can cause all sorts of problems and faults. Its a shame that they make the battery so hard to locate and replace for new owners.
    Once you know the location of the jump terminal in the fuse block you can just use any 12v jump starter to get your car going.
    Was that 9 years on the original 12v battery?
    If it was thats fantastic battery life