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May have drained battery - now what?

Discussion in 'Prius v Care, Maintenance and Troubleshooting' started by New2Priusv, Jan 12, 2015.

  1. New2Priusv

    New2Priusv Junior Member

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    On the weekend, I was trying to change the cabin air filter on my 2012 Prius v. I turned on the passenger vanity light so I could see a bit better, and I am fairly certain I forgot to turn it off when I was done. :oops: If the light was on, it would have been on for almost a day and a half, because I didn't drive the car the following day (Sunday). That being said, I was somewhat surprised as I thought that newer cars would cut all accessory power if you lock the car, so as not to drain the battery (guess not). Today, I tried to start the car and the display lights up, but just doesn't start.

    I didn't have much time this morning to troubleshoot (was going to work) but I figure tonight I can get it into maintenance mode and get a reading of the battery from there. I am assuming I could just buy a battery charger/tender and charge it back up (i.e. instead of buying a new battery)? Anything to be aware of when doing this? I was thinking about buying one of those earlier for emergencies like this. Any advice would be appreciated.
     
  2. bisco

    bisco cookie crumbler

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    do you have a charger?
     
  3. New2Priusv

    New2Priusv Junior Member

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    No, I don't have a charger, but was thinking about picking one up.

     
  4. bisco

    bisco cookie crumbler

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    you can try jump starting from another carthe battery isn't very old, so one time depletion might not be too hard on it. if you get it jump started, you need about 8 hours run time for a full charge, so you may want to pick up a charger anyway.
     
  5. New2Priusv

    New2Priusv Junior Member

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    OK - is there any particular charger model/features I need to look for, or just the most basic model will do (I have noticed they are ranging in price from $40-$75+ CDN).

    Edit: A tender/maintainer ONLY costs $40 or so, but an actual charger is $75+.
     
    #5 New2Priusv, Jan 12, 2015
    Last edited: Jan 12, 2015
  6. JC91006

    JC91006 Senior Member

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    I believe those interior map lights turn themselves off after a while. You should check the voltage on your battery before you panic.....

    If your car really doesn't start, then you should charge it asap so it won't stay at a drained depleted state.
     
  7. GregP507

    GregP507 Senior Member

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    Battery charger or a jump-start should work if the battery isn't damaged too badly and can still take a charge. I believe on the v, the charging terminal is on the fusebox under the hood.


    I recommend using ready-mode instead of acc-mode whenever possible.
     
  8. rdgrimes

    rdgrimes Senior Member

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    Be aware that a tender will not recharge a dead battery, only driving will do that. If you just want to get going again, get an inexpensive charger. But again, don't assume it will give you a full charge. Either of them *might* give you enough juice to get it started.

    Please also note: That battery is now 3 years old, so this may be an early warning that its time to replace it. And you may not get another warning.
     
  9. bisco

    bisco cookie crumbler

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    there are more than a few threads here on recommended chargers. check member 'dorunron', the king of batteries.;)
     
  10. GregP507

    GregP507 Senior Member

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    I'm not sure I agree with that. It may take a long time for a battery-tender to charge a dead battery, but it should eventually charge it up, provided it can still take a charge.
     
  11. New2Priusv

    New2Priusv Junior Member

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    Thanks for the advice. When I bought the car, I know that the battery was depleted and then trickle-charged as well (it was a showroom model) so I am fairly certain this is not the first time it has been run down.
     
  12. GregP507

    GregP507 Senior Member

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    A trickle-charger has it's place; it's a gentle way to charge up a battery and minimizing internal damage, but I've destroyed good batteries by leaving them on a trickle-charge for too long. For those of us with less time on our hands, a higher-output charger is better, but only if you are careful to stop charging when it's fully charged, (unless it's an automatic charger).

    I prefer a battery-tender myself. I've been using one for years, and I feel it has preserved my batteries for years beyond their expected life.
     
  13. bisco

    bisco cookie crumbler

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    if it's been drained twice, you may want to replace it. it might have some warranty left. also, the dealer should take 50% of the fault for letting it drain down. they should know these batteries don't hold up well to constant draining.
     
  14. GregP507

    GregP507 Senior Member

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    That's what happened to me. My car sat in the dealer's showroom for over a year, and the battery was constantly going dead and being boosted. When I took delivery, it was good for only 10-15 mins on acc-mode before the car became dead-in-the-water. Fortunately, the dealer found it to be defective and replaced it.
     
  15. Mike500

    Mike500 Senior Member

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    The same thing happened to my 2012 Prius"v" a week, ago.

    My ScanGauge II registered 9,4 volts, and the car would not start.

    The car had been sitting unused for about three weeks. I had gone in and out about 10 times in that period using both the automatic door handle and the remote.

    Prior to that, I had set up a direct Battery Tender connector in the cargo area, so that I do not have to remove all of those cargo area parts to get to the battery.

    At 9.4 volts, the doors and the hatch still unlocked with the remote.

    So, I connected the Battery Tender Jr, and left it connector overnight.

    The battery returned to 14.8 volts since, and I've not had any other issues.

    That was three weeks, ago. The Smart-key system apparently is like a "vampire" on the 12 volt battery and "sucks" juice out of it over times when the car is idle.
     
  16. GregP507

    GregP507 Senior Member

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    If I had to leave my Prius unattended for more than a week or two, I'd look into doing a mod which incorporated a battery-tender into the EVSE port. I've had my share of grief with batteries going dead while the vehicle sat unattended.
     
  17. Easy Rider 2

    Easy Rider 2 Senior Member

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    That depends on the charger AND on how flat the battery really is.
    The seldom go completely dead.
    If it IS that dead and 3 years old, he might just as well replace it.

    For most situations, a 2 amp, fully automatic charger will be best if you only have one.
    That will get you going again with a hybrid in 15 minutes or less in most situations and can be used as a "tender" during long periods of non-use.

    14.8 is NOT the battery.
    It is either the charger that was still connected or the charging system in the car.

    Wait....what ??
    Isn't the EVSE port the one where you plug in the traction battery charger ??
    If so, even you should know that is not the place for a tender for the 12 V battery.
     
  18. Mike500

    Mike500 Senior Member

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    If you don't have a ScanGauge II, a good alternative would be a voltmeter wired to an SAE connector like the one used for the Battery Tender Jr. They you can easily check voltage of the 12 volt with almost no fuss.
     
  19. fuzzy1

    fuzzy1 Senior Member

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    Changing the suspect lights to LEDs would sharply cut the current drain, by a factor of 5x to 10x, depending on LED model and brightness. This won't prevent a dead battery, but will vastly extend the time available to discover and remedy the problem. In your case, it would have allowed the car to still start this morning.
     
  20. GregP507

    GregP507 Senior Member

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    Au contraire my furry friend, the EVSE port is directly above the aux battery, and that corner would be a perfect place to situate a battery tender. Mind you, I'd have to design a bit of circuitry to ensure that only 115V is feeding to the tender, but that doesn't sound insurmountable.