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

'06 completely dead after hybrid battery cell replacement

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by probatocephalus, Aug 29, 2019.

  1. probatocephalus

    probatocephalus New Member

    Joined:
    Aug 29, 2019
    10
    3
    0
    Location:
    Texas
    Vehicle:
    2006 Prius
    Model:
    N/A
    Hi all,

    I recently replaced a battery cell in the hybrid system of my '06 Prius (~ 111 k miles). When I finished the replacement and attempted to start the car, it was completely dead. I assumed the 12v battery had been drained. Everything appeared to be fine after a jump start, but after ~ 2 mins of driving my poor beast went back in to limp mode with all the associated warning lights.

    There was some moderate corrosion on the terminals in the hybrid system, so I suspected that was the culprit. After thoroughly cleaning them I decided to double check the voltage of each cell, and discovered a different one was slightly low (7.0 when all others were 7.2 - 7.3). I replaced that one and reinstalled the battery, and again found the car to be completely dead. I haven't tried to jump it yet for fear of the same situation. Any ideas of what is going on here? This isn't the original hybrid battery on the car, as I had that swapped for a refurbished one ~ 1.5 years ago when the hybrid system stopped working. Trying to save some money and do it myself this time.

    Thanks!!

    P.S. I double checked and the orange key is locked in place and installed correctly
     
  2. offib

    offib Member

    Joined:
    Jul 5, 2016
    162
    94
    0
    Location:
    Dublin
    Vehicle:
    2007 Prius
    Model:
    Four Touring
    Was the whole back balanced, or was the one battery cell replaced and put back together?
     
  3. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
    16,463
    8,377
    0
    Location:
    Los Angeles, CA
    Vehicle:
    2008 Prius
    Model:
    II
    Change the 12v battery already
     
  4. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,861
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    It’s called whack a mole
     
  5. probatocephalus

    probatocephalus New Member

    Joined:
    Aug 29, 2019
    10
    3
    0
    Location:
    Texas
    Vehicle:
    2006 Prius
    Model:
    N/A
    I just replaced the one cell without balancing the pack, but all were 7.2 - 7.3, including the replacement cell.

    After the initial jump the would car start and drive in limp mode just fine. It only went dead again after I reinstalled the hybrid battery the second time. Should I still replace the 12v? The 12v battery going dead doesn't seem typical for a hybrid battery repair.
     
    #5 probatocephalus, Aug 29, 2019
    Last edited: Aug 29, 2019
  6. SFO

    SFO Senior Member

    Joined:
    Feb 7, 2017
    5,286
    4,225
    0
    Location:
    Northern California
    Vehicle:
    2007 Prius
    Model:
    N/A
    Welcome to PriusChat!!

    Time to upgrade your DIY tool arsenal. Pick up a mini-vci cable and a copy of techstream to read the stored DTCs.
     
    Raytheeagle and Skibob like this.
  7. probatocephalus

    probatocephalus New Member

    Joined:
    Aug 29, 2019
    10
    3
    0
    Location:
    Texas
    Vehicle:
    2006 Prius
    Model:
    N/A
    Thanks for the welcome, and good idea! I assume the cable is to connect to a phone instead of a code reader? I did borrow a friend's code reader before the battery failed initially and got the following codes:

    HV ECU:
    P3000: Battery control system

    HV Battery:
    POA80: Replace hybrid battery pack
    P3017: Battery pack becomes weak
    P3000: Antilock brakes
    C1259: HV system regenerative fault
    C1310: Fault in HV system/fault in ACTV brake booster solenoid
     
  8. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,463
    38,101
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Have you checked the 12 volt battery voltage as yet? Just to get it out of the way.
     
  9. probatocephalus

    probatocephalus New Member

    Joined:
    Aug 29, 2019
    10
    3
    0
    Location:
    Texas
    Vehicle:
    2006 Prius
    Model:
    N/A
    Haven't checked the 12v yet, but I will this evening and report back.
     
  10. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
    16,463
    8,377
    0
    Location:
    Los Angeles, CA
    Vehicle:
    2008 Prius
    Model:
    II
    12v going dead doesn't seem typical? It's a battery, of course it's typical for it to die.

    BTW 7.2 and 7.3v are really low readings (basically drained modules), I wouldn't hold out hope the battery would last.
     
  11. probatocephalus

    probatocephalus New Member

    Joined:
    Aug 29, 2019
    10
    3
    0
    Location:
    Texas
    Vehicle:
    2006 Prius
    Model:
    N/A
    -_- of course I meant the 12v going dead in conjunction with the hybrid cell replacement and working fine otherwise, not the battery going dead in general.

    Thanks for the information about voltage in the rest of the modules; I hadn't realized that they were low enough to be worried about.
     
  12. Skibob

    Skibob Senior Member

    Joined:
    Sep 14, 2018
    2,912
    1,494
    0
    Location:
    Northern California
    Vehicle:
    2006 Prius
    Model:
    N/A
    Agree 100%. How can anyone help you if they don’t have anything to go on?
     
  13. probatocephalus

    probatocephalus New Member

    Joined:
    Aug 29, 2019
    10
    3
    0
    Location:
    Texas
    Vehicle:
    2006 Prius
    Model:
    N/A
    Unfortunately all I can provide right now are the codes I posted above, as the car is completely dead.

    My main concern is making things worse by jumping the car if there is a problem other than just some bad hybrid cells.

    What I was trying to explain was that it did not seem typical that changing a hybrid cell and reinstalling the battery pack would deplete the 12v battery. Not that a battery going dead in general is atypical.
     
  14. 69shovlhed

    69shovlhed Surly tree hugger

    Joined:
    May 13, 2012
    2,170
    744
    0
    Location:
    Delaware
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    the 12v must have been replaced already; if its the original 13 year old battery its toast. look at the date code on the 12v and get it load tested. no way you can trouble shoot w/ a dead or dying 12v.
     
    SFO likes this.
  15. probatocephalus

    probatocephalus New Member

    Joined:
    Aug 29, 2019
    10
    3
    0
    Location:
    Texas
    Vehicle:
    2006 Prius
    Model:
    N/A
    12 volt battery is at 2 volts right now. No date code filled out unfortunately, but it's an intimidator 9A51P. I got the car in late 2017 and haven't changed the 12v, so it's at least that old.

    I'll just reiterate that the 12v started the car and otherwise worked fine, except on the first connection with a hybrid pack with newly replaced cells. After the initial jump I got the car running several times in limp mode with no problems (except the non-working hybrid pack, of course). I just find myself in need of a jump again and am wondering if the draining the 12v upon first connection with the hybrid pack is a symptom of a larger problem.
     
    SFO and Mendel Leisk like this.
  16. SFO

    SFO Senior Member

    Joined:
    Feb 7, 2017
    5,286
    4,225
    0
    Location:
    Northern California
    Vehicle:
    2007 Prius
    Model:
    N/A
    If the 12v battery is at 2v, it doesn't sound good or even useable. Sounds like you will need another 12v source to continue down your current repair path.
    • Do you have a AGM compatible battery charger? (the small Prius battery prefers 4 amps and under)
    Many Mechanics, Repair shops, DIYers, and Audio installers have killed a 12v battery during their normal routine; just by leaving the door open, ignition on, radio playing, etc. Many will first disconnect the 12v before doing anything to a vehicle, and others haven't a clue about how small the 12v battery in a Prius is. Just having an old 12v battery that is in a depleted state sit for any period of time will bring it down (sulphation) to a lower state of charge.
    • Did you disconnect the 12v during the repair?
    • How long was the vehicle not running during your initial module replacement? (hours, days, weeks)
    • Prior to the repair, how often was this vehicle driven during the week? (1 hour, 3 hours, 10 hours)
    Without you reading and posting the OBD2 codes (DTCs), there is only guessing at the point. It does sound like the HV battery is still an issue, and might've been run down. You may need to grid charge the HV battery pack up to a usable voltage level.

    If the HV battery state of charge (SOC) is too low, you cannot start or turn over the internal combustion engine (ICE).
    • What is the HV battery pack voltage at currently?
    • Do you have a grid, or hobby charger?
    You need a consistent 12v source or your vehicle won't be able to store DTCs for later retrieval with a hybrid compatible code reader. First find a reliable 12v source, then locate a hybrid compatible reader (example: mini-vci cable and techstream), or at a bare minimum an OBD2 bluetooth adapter, then post any reported codes here for further guidance.
     
    #16 SFO, Aug 30, 2019
    Last edited: Aug 30, 2019
    Raytheeagle and Skibob like this.
  17. probatocephalus

    probatocephalus New Member

    Joined:
    Aug 29, 2019
    10
    3
    0
    Location:
    Texas
    Vehicle:
    2006 Prius
    Model:
    N/A
    I do have a battery charger that I charge 12v boat batteries with, but I'll have to check if it's compatible with this one.

    Aha, I did not disconnect the 12v during either replacement. The first time I replaced a module it wasn't running for about a week, but now it hasn't been running for about six weeks as I have been out of town. I wasn't driving much; maybe an hour or two per week. I would regularly go several days without driving, and actually the initial issue with the hybrid pack came up after the car sat for three weeks.

    I'm out of town again but will check the voltage of the hybrid pack when I return in a few days. I don't have a grid or other charger aside from the one I mentioned above.

    Thanks a bunch to you and everyone else for taking the time post your questions and suggestions. I'll update the thread with codes when I'm able to get them.
     
  18. SFO

    SFO Senior Member

    Joined:
    Feb 7, 2017
    5,286
    4,225
    0
    Location:
    Northern California
    Vehicle:
    2007 Prius
    Model:
    N/A
    I wouldn't worry about using a jump pack, another 12v battery, or a non-running vehicle as a 12v source to jump start from.
    If the charger has a low amperage setting (4 amps or less) it should work. You might also take the 12v battery to a chain parts store, where they will offer to charge it for free. If it won't hold a decent charge, then its time to replace it.
    If the 12v battery is on the older side or has been depleted numerous times, and you have the SKS function turned on, then driving one or two hours per week may not be enough. Like the HV battery, those tiny 12v batteries like to be used when old.
     
  19. probatocephalus

    probatocephalus New Member

    Joined:
    Aug 29, 2019
    10
    3
    0
    Location:
    Texas
    Vehicle:
    2006 Prius
    Model:
    N/A
    I'm sorry for the lack of updates; I've been out of town yet again. Really hoping to find some time to work on the car in the next couple of days.

    Ok, thanks for the guidance.

    Looks like the charger is compatible! I'll give it a try and see how it goes.

    Bummer about the usage, as I don't expect that to change. My fiancee drives about the same amount as I do, so maybe I can get her to take the car on the days when I don't use it.
     
  20. probatocephalus

    probatocephalus New Member

    Joined:
    Aug 29, 2019
    10
    3
    0
    Location:
    Texas
    Vehicle:
    2006 Prius
    Model:
    N/A
    For anyone still following the thread,I returned home and was able to jump the car. Happy to report that I drove it around for about an hour and had no issues with the hybrid system! The 12v, on the other hand, is shot, as the car will not start without a jump. I'll be putting a new one in tomorrow, hopefully ending this chapter in the saga of repairs!

    Thanks for all the advice!
     
    Raytheeagle likes this.