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Any warning for dying batteries?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Charlie Bravo, Apr 3, 2013.

  1. Charlie Bravo

    Charlie Bravo Junior Member

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    My 2010 Prius is currently doing just fine, but I've been reading a lot of threads dealing with bad batteries. Is there any sort of warning I'll receive when my 12V battery is about to die? I don't want to get stranded somewhere.
     
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  2. jdenenberg

    jdenenberg EE Professor

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    The 12v battery is only require to ""Boot" your Prius. After that the "Inverter" takes over and yoiur Prius runs normally. You should periodically run some simple tests to determine the health of the 12v battery. See:

    Weird stuff happening? MPGs dropping? Test The Battery | PriusChat

    but your 2010 would probably have some differences to get into "Maintenance Mode".

    In general, your 12v battery will last a long time as long as you (mine lasted 8 years and 220k miles):
    1. Keep it fully charged which requires either long trips or the use of a battery maintainer (a low current smart charger). Lead acid batteries "sulfate" if left discharged which reduces battery capacity.
    2. Never subject it to a deep discharge - press the door lock button on the remote whenever leaving your Prius, if the doors lock then everything is fine. If they don't lock, check which door or hatch is "ajar" to avoid draining the 12v battery.
    JeffD
     
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  3. spiderman

    spiderman wretched

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    Nope. Typically people notice a drop in fuel economy and or odd happenings with door locks, etc.

    Best thing to do is check the output voltage with a voltmeter or scangauge.

    Do you drive everyday?
     
  4. gliderman

    gliderman Active Member

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    How do you check with a Scangauge? When the car is on, the 12v battery is being charged and will give you a high reading.
     
  5. blizzardwhat

    blizzardwhat Junior Member

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    [/quote]

    Keep it fully charged which requires either long trips or the use of a battery maintainer (a low current smart charger). Lead acid batteries "sulfate" if left discharged which reduces battery capacity.
    [/quote]

    Can you recommend a good battery maintainer? Where are they sold?
    Can you recommend a good battery maintainer? Where are they sold?
     
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  6. spiderman

    spiderman wretched

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    Well I do admit, I only heard of some doing it. The spreadsheet can be found here with the codes.
     
  7. gliderman

    gliderman Active Member

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    Thanks, I have the codes. Just not sure how to get a current state of charge with the car turned on through a Scangauge.
     
  8. jdenenberg

    jdenenberg EE Professor

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    Can you recommend a good battery maintainer? Where are they sold?[/quote]My favorite manufacturer is:

    Automotive Battery Charger, Car Battery Charger, Batteryminders Specials

    Their "Battery Minders" charge at a safe rate then switch into a safe low current maintenance mode. They have the additional desulfation mode which can restore capacity in a battery that has been mistreated.

    JeffD
     
  9. blizzardwhat

    blizzardwhat Junior Member

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    My favorite manufacturer is:

    Automotive Battery Charger, Car Battery Charger, Batteryminders Specials

    Their "Battery Minders" charge at a safe rate then switch into a safe low current maintenance mode. They have the additional desulfation mode which can restore capacity in a battery that has been mistreated.

    JeffD[/quote]

    Would the battery minder 1500 be enough to maintain the Prius 12V battery? I'm not sure which one to choose. I don't need bells and whistles. Just something effective but inexpensive.

    Thanks.
     
  10. jdenenberg

    jdenenberg EE Professor

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    As noted in the description for the 1500: "Not for use with Optima or Odyssey sealed AGM batteries. Choose model 2012-AGM or 12248 for these battery types." Check out the 2012-AGM (Only a bit more expensive than the 1500 and it comes with a free gift):

    Batteryminders Specials | BatteryMinders.com

    JeffD
     
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  11. blizzardwhat

    blizzardwhat Junior Member

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    Whoops, I didn't scroll all the way down to read that part.
    I'll check out the ones you suggested. Thanks a bunch.
     
  12. blizzardwhat

    blizzardwhat Junior Member

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    Last few questions. I think I'm going to order the 1012 AGM.
    How often do you charge your Prius battery and for how long?
    You just hook the charger onto the car battery as is, correct? Is it necessary to unplug the battery from the car?

    Thanks
     
  13. jdenenberg

    jdenenberg EE Professor

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    I hope that you mean the 2012-AGM as you have an AGM (Absorbed Glass Mat) lead acid battery in your Prius.

    I normally average long trips so I don't need to charge my Prius 1v (now an Optima Yellow-Top). I do keep my original 12v battery fully charged to start my home generator when needed, but this only needs to be done every few months or after use. Yes, the old battery that came out of my Prius after 8 years and 200k miles still holds a charge.

    Since the Battery Minder does put out desulfating pulses, disconnecting the negative from the car body (easily done) is a safety play, but I have not heard of any damage to Prius electronics form using one. Ask this question on the Battery Minder web site.

    JeffD
     
  14. blizzardwhat

    blizzardwhat Junior Member

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    Yes I meant the 2012 AGM. typo.
    Thanks.