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Can a poorly installed 12v cause issues with the hybrid battery.

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Jennifer Law, Feb 8, 2021.

  1. Jennifer Law

    Jennifer Law New Member

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    Location:
    Altamonte Springs, FL
    Vehicle:
    2005 Prius
    Model:
    N/A
    Hello all,

    I posted here a few months ago about my 12v and hybrid battery failure in my gen 2 prius.

    Backstory-
    First when the red triangle came on all the codes implied a 12v or break acutator issue.
    I replaced the 12v through Pepboys with a brand new optima battery.
    After installation of the 12v maybe a few days after my dash was filled with warning lights again and the red triangle.

    Thankfully, I found one of the best Hybrid mechanics in the country, Steve from Autobeyours who is centrally based in Indiana, but has a shop in Central Florida he visits monthly.

    He repaired my hybrid and confirmed that some cells were bad and replaced the frame of the battery.
    Not even a week later the red triangle came back. Got my car towed over there and no battery codes came up and there were no problems in any cells of the hv battery, but he replaced it with a new hv battery anyways.
    He did tell my my 12v was running hot and to monitor it.

    Currently-
    Three weeks go by and the car is going great. I was driving in downtown Orlando where the streets are cobble stone and rough to drive on when suddenly my battery life dropped to one bar and the triangle came on along with the vsc (!) and check engine. After a few minutes the battery life recharged and the car was driving fine, but the lights were still there.

    Before I had it towed to Titusville again (an hour away from my house) to him, I went to my local mechanic to have the 12v read and see what error codes came up. - p3000 and p0A80 and they confirmed the 12v was low.

    I then took it to Pepboys to see if they could replace my 12v under warranty. The recharge was good but the battery was only halfway charged. "Battery is good but the state of charge is low, check for proper charging system for excessive key off electrical draw" and basically told me to go f myself.

    Called auto be yours and told Steve what was going on and told him I have a weird hunch it's the 12v. He asked me to make sure the terminals to the 12v are tight and also to make sure my car had gas.

    Have my bf look at the terminals and the positive terminal's clamp is sticking out and exposed almost hitting the car wall and touching some plastic parts. Bf repositions the clamp so it's over the battery and tucked in. He also had to zip tie and lock in the censor on top of the battery because it wasn't locked in/put on correctly. I went to the gas station to fill up just to make sure it wasn't out of gas. On the way there I noticed a bit more pep while driving, the car only took 6 gallons so it wasn't out of gas. When I turned the car back on the dash was clear and is driving great.

    Did Pepboys installing my 12v incorrectly really cause all of these issues? Has anyone heard of this happening?

    Also if you are having issues with your car I recommend triple A plus. The first year you get an extra person on your account for free. It's $94 annually and I now have 8 free 100 mile tows. It has saved me at least $400 while dealing with all of this mess.
     
  2. JC91006

    JC91006 Senior Member

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    II
    The problem with your car is the HV battery, Steve has been rebuilding batteries and right now even the best rebuilders will have a hard time making older batteries reliable.

    The problem is not with the 12v. If you want the car to be reliable, you would have to get a Brand New HV battery and have Steve install it. The rebuilt batteries probably are too old. Steve is not a battery specialist so his battery rebuilds may not be as good as the more specialized shops (and there aren't many of them). Steve is great if you need to repair your wrecked Prius or need a part.
     
  3. bisco

    bisco cookie crumbler

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    'your 12v is running hot', i would like an explanation of that.

    'newpriusbatteries.com'

    how many miles on your car?
     
  4. 05PreeUs

    05PreeUs Senior Member

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    I know Steve, he seems like an honest guy from my dealings with him, but he is nearly as B@t Sh!t crazy as I am, so.... YMMV.

    Replacing "bad" hybrid cells on a Prius Gen2 and even Gen3 at this point, is fought with peril and my own experience is that it can turn into a bad game of "Whack-A-Mole" pretty quickly. This is more a problem on vehicles in hot climates (FL anyone??) or cars that are not driven at least a few days per week.

    Why is the 12v low? There are a number of possibilities, including a weak HV battery.
    1) Aftermarket electronics (radio, GPS, etc that is "on"
    2) Problem with the Inverter's charge controls
    3) Defective 12v
    4) Low HV battery
    5) 12v battery connection(s)

    I would slowly charge the 12v fully while it is disconnected from the car, it might take overnight. Then reconnect and see what you have, that will inexpensively help divide this into either a 12v or HV concern pretty quickly.
     
  5. edthefox5

    edthefox5 Senior Member

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    Vehicle:
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    Absolutely the worst car you can own when the hybrid battery fails and your financially forced to go to a battery whacker to get it back on the road which is just complete bullsh*t it will fail again....and again....and again....till you realize this sucks and move into another car.

    The alternative is buying a new hybrid battery @ $1600 to 2000 but you never posted the mileage on the car so hard to tell if that will be worth it. In your position I wouldn't put $2000 into that car no matter what the mileage.
     
  6. 05PreeUs

    05PreeUs Senior Member

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    That applies to ANY vehicle, it's just that most others it would be a transmission or engine and often at double the price. It is hard to mentally accept a lowly battery will cost over $1k.