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Hybrid Battery Cell Replacement Advice

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by kevinh52, Oct 16, 2018.

  1. kevinh52

    kevinh52 Junior Member

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    Hi all
    So I was driving to work today and I could tell something was up it started driving in surges. Then the Red Triangle, and then it lost full power. I was close to work, so I was able to get it to drive again to get to work. I luckily had all the tools needed and I pulled the battery and checked the cells. (I replaced 1 cell about 9 months ago.) So here(attached) are the readings. I have one replacement cell on hand. So I am thinking about just replacing #21, to get up and going and plan to replace maybe #10 in the future. Or is the balance of #9 and #10to far apart. A big part of it is I only have 1 cell readily available. I'm not expert at all, so looking for advice on replacement cell(s). Mainly if I could just replace that one and get by.
     

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  2. exstudent

    exstudent Senior Member

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    1) How were you able to reseal the module, after replacing one of the six cells that are contained w/in the module?

    2) You are aware that module replacement is NOT a reliable repair? Do you have a long distance tow package? What's your time worth to you? Will your employeer allow you to not have dependable transportation? Are other people (coworkers, customers, family) dependent upon you for transportation?

    3) What about internal resistance of each module? Are you trying to closely match the resistance and voltage of each module pair?

    4) Are the voltage readings loaded or unloaded?
     
    #2 exstudent, Oct 17, 2018
    Last edited: Oct 17, 2018
  3. Raytheeagle

    Raytheeagle Senior Member

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    Welcome to Prius Chat (y).

    Don’t forget there are more causes for the red triangle than a bad module ;).

    Before ripping into the battery, I would get Techstream and see what the car is telling me before the blind repair / replace routine.

    The voltages are not off by more than 1.2 volts, which indicates a failed cell in the module. I’d look for another cause.

    Good luck and keep us posted (y).
     
  4. TMR-JWAP

    TMR-JWAP Senior Member

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    (assuming this is a P0A80 code issue) Although you may have other semi-weak modules, #21 being at 7.09 v is effectively dead. As you said, replacing it will most likely get you up and going again. Odds are very good on that, but you certainly need to be making some longer term plans before the other ones bite you. At a minimum I would get some apps or techstream to allow convenient monitoring of the battery so you can have an accurate indication of an impending problem. Hybrid Assistant offers an app that you can perform load testing using the AC system. The battery can then be graphed by Hybrid Reporter and that makes it very easy to see modules (actually blocks) that are becoming weak.
     
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  5. kevinh52

    kevinh52 Junior Member

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    Like I said I'm far from an expert. I don't know how to answer your questions 1,3,and 4. question #2 doesn't seem related\helpful.

    #1 - I guess it is not correct, but today I'm planning to just take out #21 cell\module and replace it was a good spare module that i have on hand. I really don't know, but I knew something the 28 individual modules are in pairs and their voltage need to be close, then something about 14 pairs. But I not sure about the 6 cells. Sorry, I need to read some more.

    #3 / #4 - not sure. I just checked the voltage of each individual module when the HV battery was out of the car.

    —————————————————

    Thanks Raytheeagle for the Welcome. I joined back in 2013, this is my 3rd Prius. I'm have been a lurker, this is my first time to post.

    I'm going to add to this story. I was on vacation and the Red triangle came on, figure out it was the 12v Aux battery. The battery was reading 10v. It looked like it was the original factory 12v battery on my 2005 Toyota Prius(but who knows). Trying get out of FL before Hurricane Michael hit, got it jumped started and to get a new battery. Replaced it in the pep boys parking lot and left FL. So I have a brand new bosch 12v Aux battery. Got home and the weather has shifted, from being in the 70s to now temps in 50s and overnight lows in the 35s-40. This was the first day with the overnight low being so cold, then this problem happened. That's what has me thinking of the battery cells.

    Yeah, I know not the best\smart on my part. I wish I wouldn't took it out yet. I just knew it wasn't driveable, I though I would see some very bad low 6 volt modules to point directly to the problem. I have ordered the Techstream and Mini VCI it should be here Saturday.

    ——————————

    I'm changing out #21 today will update after that. I'm borrowing a basic engine light code reader today. To see if it is the guessed P0A80 code (should have checked that before).

    Yeah, I really need to think long-term, as I did replace 1 cell about 9 months ago and its been fine until now. Its a 2005 Prius with 205k miles. I think the HV battery has been worked on before I got the car. So I really don't know the overall state, it's most likely all of them will go out soon. We will see what happens after I get this one module in, but I might be in the market for some modules or a complete 28 pack. I have seen other posts, that you might sell modules. If you still do, I might have to cross that bridge. or if this doesn't work or other problems that are more expensive(aka more than the 05 prius is worth), I might be in the market for a newer prius, even though I had plan keep it until it completely dies, hopefully, that time is not now.

    Yeah over the years I have read about techstream, should have got it before now. I have it ordered now, will be here Saturday.

    I looked into the Hybrid Assistant, looks to be only android. I have an iPhone, darn. But I'm going to see what the techstream shows and then if needed I could get a andoird phone and a bluetooth dongle to give that app a try.
     
  6. kevinh52

    kevinh52 Junior Member

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    Thanks for all your replies, will update the post with results soon after the one switch.
     
  7. kevinh52

    kevinh52 Junior Member

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    Switched out #21. It started reversing out of the parking spot, it didn't seem to have full power. Then it started jerked, Red triangle came on and others. then I jerkily pulled back in the parking spot. I did get the engine codes read, by a basic code reader. P0A80 and P0AA4. I will have to research that one (P0AA4). It said "Hybrid Bat Negative Isolation Fault Stuck Open". I'm going to read\research about that code, then I guess wait until I get the techstream (Its suppose to be here Saturday.)in to see what it shows.
     
  8. TMR-JWAP

    TMR-JWAP Senior Member

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    kevin,

    I would look at your connections in the electronics side of the battery. Sounds like maybe the (-) relay is not closing properly. You may also want to verify any plugs/fasteners you touched during the work.
     
  9. exstudent

    exstudent Senior Member

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    A new OEM HV battery will give you longevity (8-10+ years), RELIABILITY, and can be moved into another Gen2, Gen3 (module swap due to incompatible cases), and possibly a Gen4.

    Expensive, but amortize the cost over the likely life expectancy of 10yrs, and it's not so bad. you could also sell the pack and it would be worth more than the Frankenstein packs floating out there.

    Prius could be worth zero. If it needed tires what would you do? Buy a replacement vehicle? Buy used tires? Buy new tires?

    You can always get a temporary 2day subscription to Toyota TIS, to get the factory manuals and trouble shooting tree. People have been able to download and save the manual for their own reference later. Will likely require some effort on your part.
     
  10. kevinh52

    kevinh52 Junior Member

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    I disconnected the three connectors on the left side of the HV Battery and reconnected them. Also pulled the orange plug and disconnected be 12v AUX battery and left them disconnected for an hour or so. Plugged them back up and it reset the codes then only the P0A80 triggered when test starting the car.
     
  11. exstudent

    exstudent Senior Member

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    #2 is relevant, you just are not looking at the big picture of life/reality.
    2) You are aware that module replacement is NOT a reliable repair? Do you have a long distance tow package? What's your time worth to you? Will your employeer allow you to not have dependable transportation? Are other people (coworkers, customers, family) dependent upon you for transportation?

    Many people look just look at cost, but fail to factor in reality and total cost (time is money, and there are other non-monetized costs).

    Module replacement is NOT a reliable repair; count on future failures. If you are ok w/ this and prepared for it, then enjoy.
    Ramification1) A future failure may occur when you are far away from home, thus the question regarding a long distance tow package. Tow companies charge a lot per mile BTW. Did you consider any of this? If yes, and you have contingencies prepared for this. Good for you.

    Ramification 2) Do you have dependents/kids? I have been told daycare/afterschool care charge a lot, per minute you are late picking-up your dependents. Did you consider this? If yes, and you have contingencies prepared for this. Good for you.

    Ramification 3) If your car is used for work? Frequent break downs won't be good for you, the company, the paying customer. If the car is just to get you to work, a lot of tardiness won't be good for you. Did you consider this? If yes, and you have contingencies prepared for this. Good for you.​
     
    #11 exstudent, Oct 17, 2018
    Last edited: Oct 17, 2018
  12. kevinh52

    kevinh52 Junior Member

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    It at my works parking lot , it can stay there for years. If I need to tow it I have access to a car hauler. I have other transportation. I have plenty of time.

    Ok so that’s out of the way.

    Exstudent,

    Please I am really just looking for useful information not psychology stuff.
    I’m really thankful that you took the time to post. Please don’t take it the wrong way, I’m just looking for real help.
     
  13. exstudent

    exstudent Senior Member

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    The Gen2 (2004-2009 model year) Prius HV (High Voltage) pack consists of 28 modules as you saw.
    The computer monitors the HV battery in 14 blocks (pairs of modules; 28modules/2pairs-per-block = 14blocks).
    A module contains six cells, enclosed in a non-serviceable package/design/container. Thus my inquiry of:
    1) How were you able to reseal the module, after replacing one of the six cells that are contained w/in the module?
    You replace/swap out modules not cell(s). It is possible some talented DIY person just might be able to do a cell replacement, but have not read about such a person, yet.​
    Resting (unloaded) voltage is semi-useful. A weak module will easily stick out, as you have observed yourself. A marginally weak module might show-up fine w/ your DVM; apply a load, and this same module may show-up weak. Thus the importance to test with a load.

    Resistance is another factor to consider when swapping modules. Put a module with too low/high of a resistance compared to its mating pair, expect a failure very soon. Now, how does this altered pair compare to the other 13 blocks. You want all 14 blocks close in resistance. Perhaps now you can see why module replacement is NOT reliable.

    Forgot about capacity. Ideally you want these close for the blocks too.

    Many people don't know the complexities involved. This isn't your remote control at home where you can just swap in a healthier AA and get away with it.
     
  14. kevinh52

    kevinh52 Junior Member

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    Sorry my bad,, I was calling it the wrong thing(cell).. Module for now on.(y)
     
  15. kevinh52

    kevinh52 Junior Member

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    Where I'm at now.
    I have ordered Techstream, it will be delivered on Saturday.
    So I'm going to wait until that gets here and run it and see what it finds. Then depending on its results, figure out the next step.

    As always I'm looking at the value of my 2005 Prius with 205k miles (car might be worth 3k) vs the cost of fixing, to see where the line is \ better off to cut my losses and look to purchasing a newer Prius. Really would like to get it running again. Thinking of this reminds me, sometimes I have heard a louder sound coming from the engine compartment, but not all the time, not sure if that points to a future problem or even if it's related to the current one.

    Options I have in mind if it points to just the HV battery.
    --Find a good price on some modules or a complete rebuilt set/kit, maybe from some trusted forums members.
    --Check on any remanufactured HV battery options.
    --Find out the real cost of a new HV battery. (i thought I have seen them around $2k-up, but not sure.)

    If Techstream leads to other problems
    --See if I'm capable of fixing it.
    --if not tow to the dealership, figure out the cost

    If anyone has other ideas, I have open ears. But I know I won't know anything until techstream gets here. I will post an update when that gets here.
     
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  16. 2k1Toaster

    2k1Toaster Brand New Prius Batteries

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    If you're reasonable at DIY there is another alternative to replace.
     
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  17. exstudent

    exstudent Senior Member

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    No offense taken. You clearly have contingencies in place, good for you. Most people do NOT, and do NOT factor in the reality (not psychology) of HV failure (esp repeated failures); this is just a difference of opinion for you and I.


    Factual information below that you may, or may not, find helpful:
    2k1Toaster's company is a viable option for a new HV Battery (via kit), if you can NOT find a dealer to sell you the HV Battery at a price you deem reasonable.​

    Techstream installation is easiest on a 32bit Windows laptop. Mac install possible, but you will have to search. You may have to return multiple miniVCI cables b/c the imitation cables lack quality control.​

    Most have found the following useful:
    A new OEM HV battery is pricey, but it will likely give you 8-10+years of reliability. Cheapest online price for a genuine OEM HV Battery, from an actual dealer is $1699.70; Conicelli Toyota; you would need to call and verify that they will sell to you, as not all dealers will do so. Don't forget, you should always call local dealers to see if they will beat or match the cheapest online dealer part price.

    Amortize the cost over the likely life expectancy of 10years, then it might not be so expensive for you.
    $1699.70/10years = $169.97/year = $14.16/month = $3.54/week = $0.51/day
    Give-up 3 Starbucks latte a month, for the next 10years, you just paid for this HV Battery.

    The car could be worth $zero. But, the HV Battery gives you flexibility b/c it can be transferred into a younger/lower mileage Gen2 (2004-2009), or into a Gen3 (2010-2015) via module swap into the Gen3 HV Battery case, and possibly into a Gen4 (module swap due to different HV Battery case). Also, you could sell the OEM HV Battery, recovering a fair amount of your expense, if a cost prohibitive auto accident or future repair bill occurs.

    A used/rebuilt/remanufactured/reconditioned HV Battery is NOT a reliable repair. Very few good "rebuilds" exist b/c the Gen2 modules are 9-14 years, old and getting older.​
     
    #17 exstudent, Oct 17, 2018
    Last edited: Oct 18, 2018
  18. kevinh52

    kevinh52 Junior Member

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    So I got Techstream. I just connected it to the car and clicked the Health Check button. It has been running for over 45 mins. Its stuck on 14 of 14. (attached picture). I guess I'm going to let it go on for another hour and then maybe just close the program and try it again. Not sure how long to wait, like is it hung up, or does it take this long?
     

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  19. exstudent

    exstudent Senior Member

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    Hmm. I'd say something not right.

    I have Version 8, and it took maybe 8-10 minutes? I wasn't timing, but I could see slow steady progress. 45min, I would have gone crazy.

    Maybe uninstall and reinstall the software? Maybe install an older version: 8,9,10,11,12?
     
  20. 2k1Toaster

    2k1Toaster Brand New Prius Batteries

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    All these versions of Techstream are gray market. Basically they're illegal and hacked and usually contain all sorts of spyware and trojans. Knowing this you can sandbox it. Don't install it on anything that connects to your home network EVER.I see the network connected icon in your screenshot...

    And because they're hacked, they have some screwy behaviour some of the time. 45 minutes is too long. But I have seen 10-15 minutes before depending on the scanner. It usually takes 2 minutes on my Prius with my scanner.

    Also they mostly enjoy running in XP x86. So a VM running XP x86 ontop of whatever you want with the network adapters disconnected is the best and safest way of doing things.
     
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