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DIY 12V Battery Replacement & Other Issues

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by unit333, Sep 16, 2014.

  1. unit333

    unit333 Junior Member

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    Hello everyone

    I posted something the other night in regards to my dashboard issue but the situation has slightly developed so i wanted to quickly list everything and the steps I am considering to get your recommendations. Please see below

    1. The other night I turned on the car and the Instrument Cluster was dark and won't come on. Car drove just fine without it.
    2. This morning I went to start, the entire display came ON totally fine, however the car actually didn't turn on. It was that kind of being ON in which all little graphics come on, the radio is on, but the actual engine is off, so is the hybrid "ready" display. Weird. So I attempted to turn the car off and it wouldn't work! It took holding the start button for a few seconds till everything shut down. Then I powered the car back on and everything was fine, just like that. Attempted the same thing a few times - all good...
    3. One thing I noticed, and maybe I am wrong, but when I power off the car I remember usually only the clock light stays on for like 10-15 seconds and then it goes dark. Now both the clock and the mileague indicator stay on for a bit and then go away...Am I imaginging things?

    Anyhow, from reading boards, other problems, etc this sounds/looks like the 12V battery might be messed up and is confusing the car electronics. If we imagine for a moment there is no other major problem, would replacing the 12V with a new one potentially solve this?
    I got the car new in Jan 2010, so its been almost 5 years, it doesn't sound all that unlikely that it might need replacement, no?
    My main question is if some of you agree with my assessment, is it an easy job to replace the battery myself?
    (per this thread 12v battery replacement cost | PriusChat)
    Looks like there are various batteries I can get and do it myself, if its as easy as opening the panel in the back and unplugging a few things and plugging the new one in?
    Dealing with the Toyota dealer here, hoping they replicate the same issue, avoiding to get ripped off, what a headache, trying to figure out a solution myself before i take this route...

    thank you
     
    #1 unit333, Sep 16, 2014
  2. bisco

    bisco cookie crumbler

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    this sounds like the thread, 'weird things happening? check your 12 volt'. why not test it first? just takes a minute. if it needs replacing, it's an easy diy, and i would grab an oem from the dealer. it's not a matter of plugging and unplugging, you need a wrench or two, and have to unbolt the battery positive and negative clamps. there are plenty of threads here with advice and pics. if your uncomfortable and want to save a few bucks, ask a local mechanic how much to install, they are usually cheaper than the dealer. all the best!(y)
     
    #2 bisco, Sep 16, 2014
  3. Mendel Leisk

    Mendel Leisk EGR Fanatic

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    A simple way to avoid any fit issues if you go the DIY route is to replace with the original battery type. Check with the dealership, they should have it.
     
    #3 Mendel Leisk, Sep 16, 2014
  4. kbeck

    kbeck Active Member

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    A lot of the 2010 Priuses are hitting end of life on that 12V battery, including mine, which was bought in December 2009. Last August, went to start the car and nothing happened. Called the wife, had her bring a 10 mm wrench and a voltmeter; the battery was reading 5.9 V (!). Jumped the car, got it to a parts place, pulled out the old battery, put in a new one, and was off to the races, no problem.
    Interestingly, no oddball problems before battery death. But a lot of people have been reporting oddities.
    It's not like this car stresses the 12V battery much; the current is used to boot the computers and keep the headlights running. So I suspect that it's simply end of life of the battery and not much else.

    KBeck
     
    #4 kbeck, Sep 16, 2014
  5. unit333

    unit333 Junior Member

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    Taking it to the dealer to check the battery on Saturday. Apparently they do that for free. I am sure the point is to get you in so they can try to sell you as much useless crap as possible.
    In any case, if it is the battery and they can replace it with an OEM one, where can i go to compare prices? I know they will rip me off no matter what I just wanna try to control how much they will try to overcharge me. If I had an idea about prices before hand then I can try to negotiate or just buy it myself and get it installed somewhere else. I keep googleing for prices but can't seem to find anything...
     
    #5 unit333, Sep 17, 2014
  6. Mendel Leisk

    Mendel Leisk EGR Fanatic

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    A couple of things you can do:

    1. Check the battery's voltage with a digital multimeter, with car off: 12.6 volts or higher, there's NO problem. 12.4~1.5 volts, it's showing it's age. Less than 12.4 volts, it's going downhill. At this point you could try a low amperage smart charger session, and see how it goes. Or with the age, maybe just go with replacement.

    2. For you consternation about prices, and if you're willing to DIY the replacement: phone a few parts departments. There could be significant variation. And if they're all close, that should at least assuage your fears of paying too much.
     
    #6 Mendel Leisk, Sep 17, 2014
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