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Gen II Prius Battery Solution? (140,000)

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by balancedms, Sep 14, 2014.

  1. balancedms

    balancedms New Member

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    I have been doing a great deal of research with regard to solving my new 2007 Touring model Prius, battery issue (140,000 miles). I did a decent amount of research prior to buying a Prius, and thought it was a safe investment as I do a large amount of driving, etc, etc... and long story short, 10 days after buying it I had an apparent battery failure. After reading a large number of PriusChat chats - I decided to try and post a message looking for expert guidance.

    From what I can tell, I have a relatively well functioning battery, still getting 42 MPG after the 'triangle of death' and many other warning lights appeared on my dash. Since these codes have appeared in vehicle computer, the vehicle seems to be running less with battery assistance by default. Prior to the error codes I was getting 45 MPG with little effort, driving at 70+MPH with cruise control on, which seems to be relatively good MPG from what I have seen. I used this brief battery evaluation to check the battery and even with warning codes on dash etc... the batt tested better then 'new battery' tested in this video:


    After check engine light and triangle of death appeared I took the vehicle to a Toyota Service location in NC and had the vehicle tested. They found 2 codes (that they informed me of), someone else found a total of four, which I will list here: POAFA, P3000 (the two Toyota listed), C1259, C1310. The Toyota technician and service person told me that they found 1 'bad' cell that was at 7(volts or something) and the others were at 16(something) - I believe he said cell1, or the first one in the series, and the rest of the cells were fine. Also they said that both the Hybrid and Battery ECUs would need to be replaced. They informed me that the reason for the two ECUs needing to be replaced was a service bulletin for replacing them when replacing the hybrid battery. So that is one Battery, one Battery ECU, and one Vehicle Hybrid Control ECU - estimated cost $4500, best price via OEM Toyota service and parts (best price of all local dealers). -By the way, I also did the whole run through of calling Toyota corporate and pleading my case to no avail, and I am in NC, so no CARB state warranty, and bought from small lot with NO warranty, AS IS. Finally, last detail - the original Toyota dealer I spoke with, that did the diagnostics, told me there was a chance that replacing the two ECU's could resolve the problem entirely, so I did get used ECUs from a local wrecking yard figuring I could replace them both myself and start there - and I haven't done that yet, before I rip into anything I would like to be as prepared as possible with the big picture - used parts have 60 day return policy.

    I have a whole slew of questions after my research, and bottom line of course is that I am trying to resolve the problem for as inexpensively as possible:

    To start, I see my options as such:
    If replacing ECUs only doesn't work;
    1. Used wrecking yard battery (as fresh as possible, from as new a car as possible) $800-$1000
    2. Reman the battery myself using a new cell(s) - more questions below on the practicality and longevity of this later in combination with cycling/balancing the battery with charger
    3. A cheep reman battery - many dealers out there, and I have seen mixed reviews on all - *would like detailed opinions/input on this point as well
    4. A new OEM battery which I would install myself, and I believe I could get from a local Toyota dealer for under $2500 (this was a quoted OEM price for a battery replacement job, including labor - seems like a good price and perhaps a #5 option)

    Any constructive comments on above options would be appreciated.

    Specific questions:
    1. Is replacing individual cells and then draining and cycling/balancing the battery a valid, long-term option? -especially in my case with a relatively well working battery?
    2. Would replacing ECUs and charging/cycling/balancing the battery potentially fix the problem entirely?
    3. Any other testing/diagnostic things that could be performed to help me resolve my issue? I have seen many people on PriusChat that have needed a replacement battery and were getting poor gas mileage etc, but that did not happen in my car, could there be other things going on that I should look at?
    4. I live in a hilly area and was coasting down a hill in B mode (on the shifter column), as it was advised for battery life, via PriusChat, and shortly after (less then a minute) shifting back into D (normal drive mode) all the dash warning lights appeared. I have heard of many batteries failing after there battery looked 'green' or 'fully charged', 'which was rare for the vehicle'. I did notice that my car rarely appeared fully charged, but it was common after descending down any large hill; I had only tried descending (less then 40MPH by the way) in B-mode this one time. Could any of these things be a part of the story here? I would also like to get confirmation as to the best way to drive a Prius, with regard to the D- and B- driving options? And, any other battery longevity driving tips? I haven't found a concise answer to any of these questions.
    5. Could replacing the ECUs really help at all, was there something in the malfunction codes that would have indicated this to the Toyota mechanic that thought replacing just the ECUs could fix the problem?
    6. Lastly my car is driving fine, besides all the dash warning lights? Would there be a recommendation to, or to not, drive the vehicle until I figure out a solution? I could see arguments for both.
     
  2. vskid3

    vskid3 Active Member

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  3. balancedms

    balancedms New Member

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    I am in contact with him. I don't know which model would be best: the standard or discharger model, and if I am going to end up needing to buy a new battery I may wait to spend the additional $400 on this. Thanks for writing. I am interested in this! Have you had experience with these yourself? Also, do you know if you need the charging balancing model, and a discharging model that is in developement, or would just the charger do the trick?
     
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  4. balancedms

    balancedms New Member

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    Also good point about the 12V - I feel real smart!
     
  5. daveabitz

    daveabitz Junior Member

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    If you buy new chat folks say get a new Gen III since the Gen II's have sat too long.
     
  6. SageBrush

    SageBrush Senior Member

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    If this is in regards to the battery, be aware that the modules have to be put in the older case.
     
  7. balancedms

    balancedms New Member

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    Thanks - just reviewed this a bit here: Gen3 HV batteries for Gen2? | PriusChat
     
  8. 93dawg

    93dawg Junior Member

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    I am just guessing that maybe your defective 12v battery caused all of the lights and codes and somehow they need to be reset, especially if everything seems now to be operating okay since you replaced the 12v battery. Surely somebody here with more Prius smarts can come up with a good answer or tell me that I am guessing wrong.
     
  9. balancedms

    balancedms New Member

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    I did not replace the 12V batter. This was a video I thought was for gauging the HV (200V) battery - that I used early on to try and figure out what was going on, and was mistaken - it is only for the 12V battery, and doesn't appear to have anything to do with my issue. Early mistake that I missed prior to researching anything and then continued to gloss over, until someone pointed it out.

    I will say though, that getting 42-45 MPG (while not trying to get the best MPG) seems to be pretty good, so I think the HV battery should be in relatively good condition.
     
  10. Patrick Wong

    Patrick Wong DIY Enthusiast

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    DTC P0AFA is not a valid Prius DTC.

    DTC P3000 means the battery control system has a malfunction and is reported by the hybrid vehicle ECU. This is probably why the dealer mechanic recommended the traction battery ECU should be replaced. However this DTC might be induced by a battery module failure, so I would start by figuring out a solution for the failed module.

    DTC C1259 and C1310 are posted by the skid control ECU because it recognizes that the hybrid vehicle drivetrain has a problem. So that doesn't add much to the troubleshooting process.

    Assuming that a battery module has indeed failed (which you can verify by opening up the battery case and measuring individual voltages of each of the 28 modules) then you could try replacing it. However your success will depend upon how closely the replacement module matches the other 27. The battery voltage under load has to be within around 0.2V across the 28 modules or else the traction battery ECU will log a fault. That is not so easy to achieve considering the peak current draw can exceed 80A. There are many posts about various techniques that owners have tried to balance modules. Obviously you need to become aware of the safety practices required when dealing with a high voltage, high current situation. One mistake and you could easily kill yourself.

    I would not replace the ECUs yet until you find that a problem persists after the traction battery has been replaced or repaired - or if you find damage to the traction battery ECU due to corrosion. Since the module next to the ECU failed, maybe it has leaked electrolyte which damaged the ECU. Look for used ECUs on eBay.

    If you plan to DIY my suggestion is that you obtain Mini VCI (on Amazon.com) so you can be self-sufficient with regards to obtaining DTC and being able to monitor battery module pair voltages without having to open the battery case - these capabilities will be very useful as you test how successful your repair is. The typical battery module pair voltage will be around 16V as your dealer service writer mentioned. (Each module has a nominal voltage of 7.2V but the actual voltage is typically ~10% greater.)

    My personal plan to deal with this issue if it happens to me (my 2004 has 181K miles now) is to buy a 3G used traction battery and move the 28 modules to the 2G battery case. Good luck with your service decision.
     
    #10 Patrick Wong, Sep 14, 2014
    Last edited: Sep 14, 2014
  11. Texas Hybrid Batteries

    Texas Hybrid Batteries Senior Member

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    balancedms,
    I've remanufactured several dozen second gen batteries and this is what I would do. Don't replace your ECU or battery control module, that doesn't seem likely to help to me. You can verify what the dealership told you by testing the cells in your battery with a multi meter. Check Dorman Batteries website they have some good videos that will show you how to disassemble the cargo area of the car and get to the battery. REMOVE the service disconnect before doing anything with battery. Just leave the battery in the car and take the main cover off of it. With cover off you can pop the black plastic covers off of the battery terminals. Get your multi meter and test the DC voltage across each module. You don't need to remove any of the bus bars or the main connections from the car to do this. Again, make sure that disconnect is removed. Each module should have a voltage of 7.2 give or take a little. When a module fails it drops by 1.2 volts. So if what the dealership told you was true you should find one of the first modules with a voltage around 6. If you find the bad module I can guarantee you that's what is causing the problem, not any of the computer modules. Reconditioning batteries (or integrating a replacement module) is a tricky process that requires being able to discharge the modules individually and measure their capacity. They should all be capacity AND voltage balanced before you can reassemble them. There is a lot of detailed information in other forum threads on battery building. I normally find the failed modules somewhere near the center of the packs, it gets hotter there and those cells age quicker. Check your cooling fan and make sure it's clean as well. If you do all of that and it looks good then I might consider replacing the battery computer, if you need one let me know, I have a pile of them and I'd be happy to sell one if you want.
    The last piece of advice I have is be very careful buying a used battery at a salvage yard. I buy quite a few that way for parts and a small percentage of them would have worked if installed. They normally won't give any warranty or written guarantee because it's "electronic equipment". The problem is that by the time the salvage guys get the battery and have it ready to sell it has been sitting for several months since the car got wrecked. In that time the weakest modules normally self discharge enough that they go bad. It doesn't matter to me because I'm only getting them for the good modules though.
    Hope any of this helps you and good luck getting your car going again.

    Matt Sauer
    Owner Operator
    Texas Hybrid Batteries, LLC
     
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  12. balancedms

    balancedms New Member

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    Hey - Thanks for the advice - I agree, I have not been able to find any reference to the code POAFA anywhere, but that is what the Toyota tech told me and I saw the code on a scanner with my own eyes. Any idea about this or what it could mean? I've purchased a mini VCI and am waiting for it. Thanks for the input - much appreciated.
     
  13. balancedms

    balancedms New Member

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    Hey - Thanks for the advice - I appreciate it and very helpful. What are the chances of finding a decent battery at a yard? You recommend Gen3 batteries/parts? I've noticed some on here recommend replacing cells with cells from a Gen3 - also if I proceed with a rebuild, I would love to pick your brain about details of this further. What would you do in my position - that would have the highest likely-hood of success, of course? I've noticed some reman batteries are nearly the price of a salvage batt. Thanks
     
  14. balancedms

    balancedms New Member

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    Best battery building guides?
     
  15. Texas Hybrid Batteries

    Texas Hybrid Batteries Senior Member

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    These all have good information. If it were me I would stay away from salvage batteries unless they are willing to give you a warranty. I'm not going to tell you not to rebuild your battery but I will warn you that it's a frustrating process with a steep learning curve. I should clarify, reconditioning is a pain, swapping parts like from a gen 3 to yours is easy as long as you take the precautions.
    Try to find a remanufactured battery with a warranty if it were me. Get Falcon to ship one to you, it should be cheaper than a salvage and they fix them right. To bad your not in my area, I'll put a new battery in a car just to see if it fixes it. If not we put the old one back in and customers pays $150 for the mobile install. Diagnostics at a shop would normally be that much.
    If your mechanically inclined install it yourself, it's easy. Having said all of this, test your battery to make sure you have a failed module(s) before you spend the money on a battery. Let me know how you like your VCI when you get it. I've read good things about them but haven't used them. I went with EngineLink on my iPad and it's worked good so far.
     
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  16. balancedms

    balancedms New Member

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    Falcon vs ReInvolt (now Dorman) vs Greentec Auto? Any opinions?
     
  17. balancedms

    balancedms New Member

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    Sounds good. I will let you know. I was looking for a good iPad/Phone option - and didn't find much. Falcon looks like good prices - Have you seen there batteries in operation? Good longevity? The Gen2 battery reman with Gen 3 cells looks like an interesting option. Have you seen Greentec batteries in service? Thanks again for the input.
     
  18. Texas Hybrid Batteries

    Texas Hybrid Batteries Senior Member

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    From what I know about rebuilding batteries and what I've read on falcons website it looks like they know what they are doing. I have one co worker that bought from greentech (the cheap battery, not the gen 2 w/ gen 3 cells). That battery has 6 months use and it's working great. Both of those companies give a 6 month warrantee on their work. Greentech extends the warrantee to 18 months if you pay them the $300 for installation. I would expect both of those to be good options.
     
  19. hybridfan05

    hybridfan05 Junior Member

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    Long time member of Prius Chat but never posted anything, until the latest problem and muddling through to the solution. Long post.

    Story of a hybrid battery change, just sharing my experience -

    About a month ago, I get the dreaded Red Triangle, (!), VSC light up on my 2005 Prius, 167K miles. Located near Providence, RI.
    Went to the dealer to get it evaluated and they indicated the hybrid battery change codes - Cost $110. Battery replacement quote from dealer - OUCH - $3600, all inclusive. Based on the age and mileage of the car, started looking for other options.

    Went to the best resource for any Prius issues - Prius Chat and found out about reconditioned batteries. Surprisingly, nobody doing any such work in the New England area, considering this is a good base market for the Prius. Found about 3 suppliers who could work (thru' PriusChat) -
    1. Dorman Hybrid - don't sell direct, found their distributor from online search based in Seekonk, MA, waysideauto-biz
    2. Prius Rebuilders (aka Falcon Hybrid), falconhybrid-com
    3. High Voltage Solutionz, hybridparts2go-webs-com

    Dorman’s distributor in Seekonk, MA gave me a quote for approx. $2400 for a reconditioned battery (still a shock !)

    Prius Rebuilders based out of NY gave a quote of $1400 including installation at my location, 6-mth warranty.

    HVS based out of Florida gave a quote of $1200 including installation at my location, 18-mth warranty.

    Didn’t believe HVS quote (how are they making money?), so went with Prius Rebuilders. Paid via credit card. BAD MOVE – never got a straight answer on when they could do the work, always “within the next 2 days”. Took a month, finally got mad and cancelled the order, got a full refund.

    Finally went with HVS – they told me 1 wk from order. Payment upon completion of work, no advance. Right ON TIME, I get a call from their Tech 24 hours prior to install. He came and did the job in 20 minutes. The codes got reset and took the car for a drive with the tech. So far working fine (has only been a few days). Would definitely recommend them to anyone looking for a reconditioned hybrid battery.

    Talked to the tech from HVS and learned a little bit about their business – they cover the country. Have techs located in various geo regions, he covered the East Coast. Basically he drives up and down the coast and installs batteries as needed. The drop-off for reconditioning is somewhere in VA. The company has figured out the logistics of this process – basically having a network of techs, reconditioning locations and online sales.

    Moral (for me): Just because it is the lowest cost, does not mean something is wrong. I could be proven otherwise, but so far it’s been good.
     
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  20. SageBrush

    SageBrush Senior Member

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    Nice story, thanks. Pls keep us updated how the battery works out for the next few years.
    Personally, I avoid any company that cannot spell their own name unless it is a clever word play.

    As for the warranty, note that YOU pay $250 shipping per episode.