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accessory battery life expectanct

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by wesayso, May 5, 2015.

  1. wesayso

    wesayso Member

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    How long (miles/years) can we expect the 12 volt accessory battery to last? My 2011 is just over 4 years and 44K miles.
     
  2. bisco

    bisco cookie crumbler

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    it depends. if you never run it down, by leaving a light on etc., i think they're good for 6-8 years.

    if you have, it's more difficult to put a time on it. some would change it now, if you don't mind possibly wasting a couple hundred bucks.

    unfortunately, one thing you can't know is if the dealer ran it down before you got it.

    i prefer to monitor it quarterly. it takes 5 minutes and you will get a pretty good heads up before it's on it's last legs.
     
  3. Mendel Leisk

    Mendel Leisk Senior Member

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    You should be ok for another year or two. It's maybe best to think of it like an oil change, albeit with a longer interval: pick time interval, say 5 years, and just slam in a new one at that point.

    As bisco says, it depends:

    1. Any door ajar or map light left on events?
    2. Do you drive daily, mostly? Or less? Or a lot less?
    3. Ever hook it up to smart charger, just for a top up? Check on voltage with a digital multimeter? Or haven't a clue?

    Ours was replaced RIGHT at time of purchase, since it was DOA, the car having languished on the lot for some time I surmise. Come November it'll be 5 years old...

    Something I like to do somewhere along it's life span, is take the battery right outa the car, charge it, clean the posts, clean the cable clamps, reinstall. Besides the maintenance benefit, it's also a good dry run, for when you have to change it.
     
    #3 Mendel Leisk, May 5, 2015
    Last edited: May 5, 2015
  4. szgabor

    szgabor Active Member

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    12V battery life is not dependent (at all) on mileage... and even on time... but depend on use more like "abuse"... The biggest thing is temperature... it hates both really cold and really hot ... also it is sensitive to deep discharge especially in cold temps. (Other things can happen to like excessive loss of electrolyte from improper overcharge etc.)

    In case of the Prius you can run the battery in a very low SOC if you don't drive a lot and have short daily rides... (and that is detrimental to the battery)

    As suggested, the only way to know is to measure the open circuit voltage after a full charge (and rest about 2-3 hours). If the voltage is 12.3 or higher the battery is in good shape. Anything under 11.8 indicates trouble....

    There are a lots of thread about this
     
  5. Fore

    Fore Don't look back!

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    Mine went out this year if that helps any. Get yourself a battery jump pack just in case. It's also good to help jump other cars if they need it that way you don't use your own car as the source and take a chance on frying your electrical components. This is the one I bought it's nice and small works great and has saved me a couple of times not to mention others. Ama$on is carrying this one at a pretty darn good price right now. Go check it out!
    [​IMG]
    Clore JNC300XL 'Jump-N-Carry' 900 Peak Amp Ultraportable 12-Volt Jump Starter with Light
     
  6. Mendel Leisk

    Mendel Leisk Senior Member

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  7. fuzzy1

    fuzzy1 Senior Member

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    Every year, as outside temperatures drop in late fall and early winter, it seems that we get a significant number of reports of strange symptoms that get tracked down to failing 12V batteries. The youngest cars seem to be about 3 years old, and seem to be biased towards climates with hot summers and/or cold winters.

    But as Bisco pointed out above, numerous others go 6-8 years. This is more likely in milder climates.

    I'd suggest that the Prius 12V battery should have a somewhat similar life expectancy to those of non-hybrids in your climate zone. While it is small and more easily wounded by mistakes, it also doesn't have to out a large starting current, so can often get away with lower charge levels that won't start a non-hybrid.

    At 4 years, your battery is old enough to be at risk. But plenty of us normally go much longer (at least with our non-hybrids, I haven't had a hybrid past 3 years yet). And with warmer spring temperatures arriving, this is the time of year it is least likely to fail from climate aging. That risk peaks in October-December as winter temperatures arrive.
     
  8. bisco

    bisco cookie crumbler

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    my daughters '08 failed after 3 days at the airport last winter. but after a jump start, it's been fine ever since. i recommended she replace it before next winter. right now, it reads 12.4 in the morning before opening the driver door.