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Another HV battery module myth coming under fire.....

Discussion in 'Gen 2 Prius Technical Discussion' started by TMR-JWAP, Jun 26, 2019.

  1. TMR-JWAP

    TMR-JWAP Senior Member

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    Well, I had recently posted another thread about who needs a truck when you can pack 800 pounds into the back of a Gen 2. I had 8 HV battery packs stuffed in the car at the time.

    Who needs a truck when you can do this? | PriusChat

    One of those was a Gen 2. I purchased all 8 batteries from a high end salvage yard. They had a TREMENDOUS amount of inventory.

    This Gen 2 battery was on a shelf and covered with dust. It had 09F140 written on the top of the case with a paint marker. Any guesses what the 09 represents? The sales person who was escorting me through their buildings explained the coding to me after we had everything packed into my prius.

    If you guessed its for model year 2009, you're close but not quite there. The Serial number on the case was H239IAQ0079A. Built on September 23, 2005. The 09 represents the year and the F140 is the car inventory ID number. That battery was on the shelf since 2009. They didn't even know it was there, as it didn't show up on the computer system when we pulled everything. On the shelf for almost 10 YEARS. I was thinking how glad I was that he gave it to me at a core price. There's a bit of discrepancy between the case date and the module dates, but who knows exactly what happened back in 2005ish. And it looked pretty darn original to me during disassembly.

    Here comes the interesting part. I pulled the cover and started disassembly. I couldn't get the voltage sensing harness to unplug from the ecu. After a bit of minor (well, not so minor) damage to the connector, I finally got it apart. half the pins had corroded/bonded together. No big deal.

    I removed the 28 modules and clamp assembly and placed it on my test bench to start the cycling program to see what could be recovered. Recovered you say? After being on a shelf for 10 years? I silently laughed to myself about how futile this was going to be. I expected all 28 modules to be at 0 volts, and probably not even take a charge.

    I wasn't disappointed, as:

    the first 4 modules (block 1 and 2) were 0.2, 0.3, 0.2, and 0.4 volts each.
    the next 4 modules (block 3 and 4) were 1.6, 1.5, 1.9 and 1.2 volts.

    And then it happened......................................7.39v
    Not only on module 9, but on modules 9 through 20 and 23 through 28. They were all 7.35 to 7.44 volts

    Modules 21 and 22 were 2.7 and 2.6 volts.

    Are you kidding me?????? 7.4 volts on 18 modules? I couldn't believe it.

    So I connected ALL the modules to my chargers to get initial discharge information. I always document how much energy remains in each module before I start cycling. The chargers wouldn't even recognize the Block 1 and 2 modules. The other 6 modules that were not in the 7.4v range recorded ZERO mAh. The 18 modules in the 7.4v range fell between 508 and 1178 mAh. Those 24 modules were then charged overnight.

    I started a discharge/charge cycle before I went to work this morning and checked the data when I got home. The 6 low voltage modules were all >5000mAh on the first discharge. The other 18??????? No way.........the lowest was 6679 mAh and the highest was 7057 mAh. The manufacture date code on all 28 modules is......wait for it.....14XE...October 14, 2003. Modules that are almost 16 years old. Sounds a lot like that Dorman pack from an earlier thread.

    Dorman HV Battery with a new lease on life..... | PriusChat

    They built some bada** modules in October 2003.:cool: . I started another cycle after recording the data. When I checked on them about an hour ago, ALL 24 had passed 5500mAh discharge and were between 7.23 and 7.35 volts. Plenty left to go...This is going to be interesting...............
     
    #1 TMR-JWAP, Jun 26, 2019
    Last edited: Jun 26, 2019
  2. jerrymildred

    jerrymildred Senior Member

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    Wow. It's almost like American Pickers with hybrid batteries. :D
     
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  3. fotomoto

    fotomoto Senior Member

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    You never state exactly what module myth is under fire. ;)
     
  4. landspeed

    landspeed Active Member

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    Please post pictures of the voltage connector corrosion on the connector, ecu pins, and the state of the ecu itself when you open it up (especially what has gone on on the pins inside the ECU)

    Can I ask a huge favour; if you aren’t going to use the ECU, can I purchase it from you for detailed inspection under a microscope etc? This is a unique opportunity given it was a never used battery that actually kept its charge, and still it has done the voltage sense connector corrosion thing.

    If you consider selling me the broken ECU for cheap :) then please, if you open it, don’t clean it up inside at all; I want to inspect under a microscope for metal whiskers (as in my avatar pic) which was from a perfectly good ECU and invisible to the naked eye.

    Also I want to get several bad ECUs and see if I can fix them. In the future such repairs might help us keep our cars on the road (they will be a classic one day, and unlike older classics, things like ECUs can’t be made by anyone except Denso who don’t make them anymore, so.....)
     
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  5. TMR-JWAP

    TMR-JWAP Senior Member

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    Land, PM your mailing info. I'll throw the ecu and the harness in a box for you. It's useless to me, at least you can do something positive with it.
     
  6. strawbrad

    strawbrad http://minnesotahybridbatteries.com

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    I have seen this before. Modules that got drained by an ECU short recover with no damage. Kinda a deep discharge on steroids. This is different than modules that self discharge. They are not recoverable.

    Did you try to charge modules 1 to 4?

    How about that 16 year old modules are all worn out junk?
     
  7. TMR-JWAP

    TMR-JWAP Senior Member

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    As soon as the charger goes through its precharge checks, it faults on "short error" on modules 1 and 3. Modules 2 and 4 fault on "connection break". I'll do a bit more checking out after I've put the others through a few cycles.

    Maybe this is one of those times where connecting the Prolong would come in handy. Connect it and let it do a charge cycle for a few hours to see if it can bring those modules back to a condition where they can at least pass the pre-checks.
     
    #7 TMR-JWAP, Jun 27, 2019
    Last edited: Jun 27, 2019
  8. TMR-JWAP

    TMR-JWAP Senior Member

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    This post is for @landspeed

    Date code on modules is October 2003, Date code on battery case indicates it was assembled in 2005. Inventory code written on case, under 5 pounds of dust, showed it was placed into the salvage yard inventory in 2009. Other than pulling the plug from the socket, the ecu and wire harness have been untouched. I hope it gives you some interesting observations. After you check it out, feel free to post some photos in this thread or wherever is convenient. take a good look at the harness and busbars. It looks like the busbars associated with the plug damage have "corrosion" significantly different from the other busbars.

    IMG_3666.JPG IMG_3667.JPG IMG_3668.JPG
     
    #8 TMR-JWAP, Jun 27, 2019
    Last edited: Jun 27, 2019
  9. landspeed

    landspeed Active Member

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    I would be very happy to open up the ECU! I will send a PM (I actually am going to look at an ECU or two that strawbrad has - I have been so busy at work I haven't got around to arranging shipping etc.

    This will be interesting as it is from a 'good' battery pack; and hasn't been exposed to the usual stresses of being used in an actual car. I am intrigued as to what I will find inside the ECU (whether it has the melted short-circuit, or whether the batteries drained more slowly from the corrosion; there are similarities with my burnt ECU but also differences in your ECU - it looks as if there has been fluid there, which I guess would be due to water being attracted to the corrosion.

    I will be in touch! :)

    Edit : P.S. I haven't given up on emulating the battery ECU; I am rewriting the CPU core code in a structured way, and nearly have a full V850E core, with the ability to add all extensions as they become needed. So I will examine the ECU from the CPU code, from the hardware, and also try to figure out what is going on (while I think metal whiskers are sometimes involved, they could be a red herring (sort of) - because they tend to grow where there is corrosion. I think a voltage-related electrolytic process is going on. I can probably scrape off the deposits and identify them chemically; I can access a mass spectrometer among other things. It would be interesting if they were metal ions that had migrated from afar, for example!
     
  10. landspeed

    landspeed Active Member

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    I just re-read your post... The bus-bars with corrosion associated with the corroded connector / pins... Will you refurbish them? If not, I would be keen to examine some of them to see how it might link to an electrolytic process as behind the battery ECU issues!

    Edit : the original thread : The battery fires at ECU sense connector thread | PriusChat
    Edit : my ECU thread (neglected but I am still working on it) : Landspeed's HV battery + ECU teardown, analysis, experiment, upgrade thread | PriusChat
     
    #10 landspeed, Jun 27, 2019
    Last edited: Jun 27, 2019
  11. strawbrad

    strawbrad http://minnesotahybridbatteries.com

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    The year coded on the case and modules do not match. I can't remember how far off they are.

    Yea, they might just need a dumb charger to get them started. Or, they might have sat too long at too low a charge.
     
  12. NortTexSalv04Prius

    NortTexSalv04Prius Active Member

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    To OP I got a battery myth in my storage shed and you can sort out the low voltages
     
  13. TMR-JWAP

    TMR-JWAP Senior Member

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    Brad, I agree. I mentioned it, in passing, in post 1. There's a bit of discrepancy between the case date and the module dates, but who knows exactly what happened back in 2005ish. And it looked pretty darn original to me during disassembly.

    The case/module year code is different by 2. So an "L" on a module is 2010 but on a case is 2008.

     
  14. fotomoto

    fotomoto Senior Member

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    So we're all still on the same page, is this the myth on fire, TMR?
     
  15. TMR-JWAP

    TMR-JWAP Senior Member

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    I think @strawbrad said it well enough. There is so much discussion about old batteries and old modules not being worth the time or effort to try to use again. We all seem to assume that every battery out there that has a failed module is going to be a whac-a-mole project every 3 months.

    Although I do believe the whac-a-mole problem is a significant issue out there, I also believe it's not true in every case. You'll never know until you try. Although I am NOT a proponent of it, there are situations where it's the only available option for a person.

    Just over two years ago, I helped a fellow forum member who had a Dorman battery that failed. It wasn't under warranty, because they purchased it from a wrecked car. I installed a battery with 2015 modules and took the Dorman. I'm pretty sure it's somewhere on the forum. Pretty sure I did some testing on the modules and swapped out one or two. Installed it in the blue 2005 my son was using for college. We sold that car to one of his friends a couple months ago. That car and battery are still going strong. I asked her to bring it by the house every month or so to allow me to do basic checks on the car and health check it.

    A couple months ago, another Dorman. All modules from October 2003, except one gen 3 module that had been installed. The gen 3 and one 2003 module failed. All the others were rockstars. That battery is now installed in my car for testing.

    Now, a battery that's been sitting on a shelf for 10 years. 4 dead modules, probably due to draining from ecu connector failure. 4 semi-drained but came back to life and testing >6000 mAh. +18 rockstars. That's 48 modules date coded October 2003 that are all testing >6000 mAh and probably actually averaging >6500

    Just like in life, old doesn't always mean useless or dead.
     
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  16. fotomoto

    fotomoto Senior Member

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    Ahh OK.

    It may have been before you joined but I thought you might be referring to another concept of a pack sitting for years and still being good/acceptable for more use. We had a great opportunity to observe that here when a new member posted about a Gen 2 "barn find" in NJ he discovered due to a family death and wanted to get it back on the road. Last I recall, he did get it started but soon quit the forum due to fellow PC members behavior in that thread. Pity, it would have been great to know what happened next.
     
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  17. landspeed

    landspeed Active Member

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    Back in the days of NiMH phones, I remember the advice to drain it to empty, and fully recharge it, every so often, to bring capacity back; the Prius design is good in keeping it between 40-80%, but it does mean the temporary memory effect sets in, and it is difficult to do anything about it as an average Prius driver; those Prolong adverts keep showing up - in fact there is one right below as we speak! :)
     
  18. fuzzy1

    fuzzy1 Senior Member

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    Don't you mean NiCd cells?
     
  19. landspeed

    landspeed Active Member

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    I do also - although I started with NiMH cell phones (Nokia 3210, prior to that a Sagem just after 'digital mobile', that we now know as 2G, came out! They had NiMH batteries; there was only a short window from NiMH to Li-Ion IIRC. I do remember seeing a suitcase phone that had, presumably, a sealed, flooded lead-acid battery. Also, a health team that I worked with had (many, many years ago), a 'brick' mobile phone, that had 30 minutes talk-time, and 6 hours standby on a full charge, and I believe that had a lead-acid in it as well :D

    That said, I have a NiCD power laptop (actually 3 of them), 'Acorn A4 portable'; the NiCDs all died ages ago, but I got a NiMH reinstall done in the original pack; it worked well till I left the laptop stored for a few years, then the NiMHs leaked. I will DIY it at some stage!

    NiCad cells had proper memory effect, and I recall people would 'zap' them to bring them back to life; there were posts on zapping huge NiCad diesel-electric cells to bring them back to life (I guess that was hybrid reconditioning as well). NiMH cells don't have such a 'hard' memory effect as NiCad, but they still do; in fact, in this thread, the fact that the capacity recovers with full cycling shows just that - the memory effect can often be reversed in NiMH. Despite all of this, it is true that the 'memory effect' is not fully understood although there are lots of good theories.