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Updated battery problem

Discussion in 'Prius c Fuel Economy' started by Joel W, Mar 5, 2017.

  1. Joel W

    Joel W New Member

    Joined:
    Nov 26, 2016
    5
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    Location:
    Warwick, Rhode Island
    Vehicle:
    2011 Prius
    Model:
    IV
    Hello all,

    I posted a while ago about having only 45mpg on my used 2011 Prius. We found the culprit: my battery tested at 11.5 volt, instead of 12.5...so, I got a new battery. Now, I get about 47mpg and after testing the new battery (that I've had for a week), it's at... 11.6.

    Bought it at 30k miles, currently 45. Proper maintenance, and its cold where I am (freezing), if any of that information helps.

    I'm at a loss as to why my battery continued to drain upon first starting my car, why it isn't getting 50mpg, and why my brand new 12.5 battery is secretly a 11.6 in disguise.
     
    #1 Joel W, Mar 5, 2017
  2. Gasoholic

    Gasoholic Junior Member

    Joined:
    Feb 17, 2017
    35
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    Location:
    Bakersfield, Ca
    Vehicle:
    2016 Prius c
    Model:
    Three
    First off, did you check the charging system when they replaced the battery? 11.6 volts is a discharged battery, quite low. I would have to say, your not charging the battery when the car is running, or you have a draw (something on like a light) that is running it down while stopped.
    Your other battery may not have been bad, it may have just been discharged.
    Gasoholic
     
    #2 Gasoholic, Mar 5, 2017
  3. Joel W

    Joel W New Member

    Joined:
    Nov 26, 2016
    5
    0
    0
    Location:
    Warwick, Rhode Island
    Vehicle:
    2011 Prius
    Model:
    IV
    There definitely wasn't a light on. What charging do you mean? I didn't know that I had to check anything. What should I look for?
     
    #3 Joel W, Mar 5, 2017
  4. jerrymildred

    jerrymildred Senior Member

    Joined:
    Oct 28, 2016
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    Location:
    Tampa, FL
    Vehicle:
    2017 Prius
    Model:
    Two
    Check the battery voltage while it's running. The ICE doesn't necessarily have to be idling; the traction battery should charge the 12V battery either way. It should be about 14V or a little more. If not, there's a charging problem.
     
    #4 jerrymildred, Mar 5, 2017
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