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'02 winter battery drain - not charging?

Discussion in 'Generation 1 Prius Discussion' started by Tryyn, Dec 19, 2023.

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  1. Tryyn

    Tryyn Junior Member

    Joined:
    Aug 13, 2020
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    Location:
    Madison, WI
    Vehicle:
    2002 Prius
    Model:
    N/A
    Hey, gen 1 community!
    We typically drive our '02 once every 1-2 weeks to keep the aux battery charged. It's typically driven 7-10 minutes at a time (often just long enough for the car to go into idle-stop at a light.) I drove it a week ago, and just today I took it out to go shopping. It was ~30 degrees F out, and the dash lights were very dim when I tried to start the car. No [READY], no drive-by-wire brake pump noise, and no infotainment screen activity. The car is now on an external automatic charger, charging at 2A.

    The battery was replaced a few months ago by our local dealer.

    May the aux battery not be charging, or is it just not being driven enough? Or did we get a dud aux battery?
     
    #1 Tryyn, Dec 19, 2023
  2. Josey

    Josey Active Member

    Joined:
    Jun 10, 2019
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    Location:
    Virginia
    Vehicle:
    2003 Prius
    Model:
    One
    I'd say it's likely not driven enough, and when it is, not for long enough. I'll add that you should just plain drive it more for multiple reasons. The HV battery doesn't really like just sitting around either. Short of that, though, you could at least pick up something like a decent solar battery tender for the 12v. (Or a plug-in if that's easy enough).

    If you want to know if it is getting an adequate charge current, and if you have a DVOM, the next time you start it up check the voltage at the 12V terminals. With the car in Ready it should be showing something on the order of 13.5-14.5V
     
    #2 Josey, Dec 19, 2023
  3. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
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    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Definitely that.

    That's good. Our driving is just as sparodic, albeit with mostly longer drives when we do use it. In between uses, ours is always hooked up to a smart charger. Battery was installed 8 years back as of September, still testing like new.
     
    #3 Mendel Leisk, Dec 19, 2023
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