1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Bad inverter or hybrid battery?

Discussion in 'Gen 2 Prius Technical Discussion' started by scott niland, Sep 1, 2020.

  1. scott niland

    scott niland New Member

    Joined:
    Jun 9, 2020
    1
    0
    0
    Location:
    Los Angeles
    Vehicle:
    2004 Prius
    Model:
    N/A
    In the past 2 months, I've been trying to replace my hybrid battery in my 2004 Pruis through a company that sells refurbished Prius hybrid batteries. The first one they put in failed in like 3 days. I'm not kidding. They came out a second time and changed it out for another one. 2 weeks later that one failed. Ok, so the third time they came out they replaced a bad cell in that battery and said I would be good to go. Not so fast. After a few days, all the lights came back on AND the rear cooling fan began to fire up. So, I called them a 4th time. A different tech came out this time and replaced the entire battery. He said the previous one was bad. Well, wouldn't you know that one lasted about a week and all the lights came back on - again. I was beginning to notice the erratic change in charging bars as well as only having one bar shortly after I turned the car on. The rear fan wasn't coming on this time. But it's obvious this battery had issues. Or does it? I was told by one of the representatives of this company that I more than likely have a bad inverter. They said it's simply not possible for all of the batteries they've given me to have issues. However, when they run a diagnostic test to see what pops up, the only error code is for a bad hybrid battery. I recently had to replace my heater/ac control valve (code P1121 I believe). This was done at LA Car Nerds a few weeks ago. The tech said there wasn't any history of any other error codes, other than the P1121 and multiple errors showing I had a failing hybrid battery. So, my question is... Is a bad inverter causing these batteries to fail or not perform to their potential, or is this company feeding me a bunch of BS? Is there an error code for an inverter that's going bad? If not, could it still be causing issues with the hybrid battery? I just need to get the car running consistently so I can sell it.
     
    #1 scott niland, Sep 1, 2020
  2. 2k1Toaster

    2k1Toaster Brand New Prius Batteries

    Joined:
    Feb 14, 2010
    6,035
    3,854
    0
    Location:
    Rocky Mountains
    Vehicle:
    2006 Prius
    Model:
    Three
    First, don't fool yourself. There is no such thing as a refurbished battery. They are USED batteries with hundreds of thousands of miles and thousand of hours of use in them. They have already failed for someone else, and now they are your problem after a quick bandaid.

    Having said that, it does seem rather odd for that many batteries to fail that quickly if they were truly balanced before installation. You should expect failure in a couple weeks at the earliest, not 3 days later like you had twice. But here's the thing... The battery is really stupid. It's just a hunk of goo that stores energy. The car doesn't really care about it unless something is wrong. All the HV systems have their own error codes and if you had a bad inverter you'd know it with inverter codes.

    My question would be when they are replacing your battery what are they physically doing? Do they come out, tear your car apart and replace the modules at your car? Or do they bring a whole new battery pack and swap that in, never exposing the modules inside?

    I ask because the most common problem that isn't a battery that causes these issues is the hybrid battery ECU. It can grow whiskers and have shorts, both which cause erroneous battery reading errors. If they are replacing modules at your car, and you have kept the same ECU the whole time, that would be my #1 suspicious part. If they're replacing the whole battery tray, the ECU is inside it so you've had 3 different ECUs and it is also highly unlikely that would happen to all 3 if there has been testing.
     
    #2 2k1Toaster, Sep 1, 2020
    CanTG and Aaron Vitolins like this.
  3. edthefox5

    edthefox5 Senior Member

    Joined:
    Jul 25, 2007
    10,096
    4,795
    0
    Location:
    Clearwater, Florida
    Vehicle:
    2007 Prius
    Model:
    Two
    Hey Scott this is pretty common.

    It’s called a whack a mole battery repair.

    Please use the search forums tab up top and search

    Whack a mole

    To see what others are experiencing. It’s quite the scam.
     
    #3 edthefox5, Sep 11, 2020
(You must log in or sign up to post here.)