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Hybrid battery reconditioning veterans I need your help!

Discussion in 'Gen 2 Prius Technical Discussion' started by TrillingThrows, Mar 19, 2021.

  1. TrillingThrows

    TrillingThrows New Member

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    Hello all I'm new to the forum and new to the world of cars in general I have nonexistent mechanical skills/knowledge, and I recently became unemployed , thankfully I have money saved up and a LOT of free time in my hands. Recently I've realized that learning about hybrid systems specifically and cars in general is a path that I want to explore in life and maybe eventually down the road make a living out of it. This forum is a wealth of information , and I have been trying to learn as much as I can both by searching for old posts and following certain members and reading through their comments and posts , but I still have several questions and please don't feel obligated to answer all of them , I'm at the stage where receiving answers just causes more questions so bear with me:

    #1 Can you guys drop the usernames of people who you know are experienced at this so I could follow them and keep on learning? So far I follow TMR-JWAP , S. Keith , jeff and 2k1toaster , if you guys are reading this I cannot thank you enough for sharing your knowledge with us.

    #2 With a budget of $3000 what would be the most bang for your buck tools to purchase? I have all the basic tools to remove the battery , but other than a basic voltmeter I have no diagnostic software/tools or anything to actually recondition the batteries with.

    #3 What are the pros and cons of reconditioning the battery with grid charging tools vs individual ones. I know about grid chargers and how HA seems to be the favorite here , but I've also seen setups of people (TMR-JWAP) that buy individual hobby chargers and dischargers and do it that way.

    #4 What are the most common "uncommon" reasons the hybrid battery goes bad? For example I know that the inverter water pump usually goes bad , and when it does ,it overheats the inverter and messes up the hybrid battery. Essentially I want to be prepared for the most common (actually wouldn't mind to hear any uncommon ones either) scenarios in which I properly recondition a battery , but something else in the car causes it to mess up.

    #5 What are other skills pertaining the mechanical aspects of the car that have a good time spent: $$
    ratio?
    For example like I mentioned before about the inverter pump ,it's a relatively simple fix , it's common, and in terms of time spent fixing and money received for the service it's great ,so I was wondering what other mechanical services/skills I can learn that have similar ratios.

    #6 Any tricky DTC experiences you have had regarding the hybrid battery that you think novices could benefit from knowing?

    Sorry for the gigantic post and thank you for taking your time to help a noob like me out , much appreciated.
     
    #1 TrillingThrows, Mar 19, 2021
    Last edited by a moderator: Mar 20, 2021
  2. bisco

    bisco cookie crumbler

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    what are you driving? they didn't make awd in 2006
     
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  3. alftoy

    alftoy Senior Member

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    #1 TMR-JWAP , S. Keith , jeff and 2k1toaster, Olrowdy

    Lots of info describing hybrids even tho it is for a Honda Insight. The charger build will work with 2006 Prius.
    Substitute Meanwell HLG-80H-350A for 60H, sub 3/500vdc ammeter for 200vdc (300 4Bit hard to find), use 500vdc 10amp.
    Pdf modified schematic attached below for Gen 2 Prius
    V2-grid-charger-discharger MOD
    MparkH V2 Grid Charger Build (Illustrated) | Honda Insight Forum

    HLG-80H-C350A MEAN WELL USA Inc. | Power Supplies - External/Internal (Off-Board) | DigiKey
    GWUNW BY42A 500V 10A DC 4 BIT Digital Voltage Ammeter Current Tester Meter Voltmeter Dual Display Red Blue Green LED|display meter|digital meterdisplay voltage meter - AliExpress

    S Keith now frequents Honda Insight Central and Green Hybrid. He is a wealth of info.
    HCH1 DIY IMA Reconditioning - Page 4 - GreenHybrid - Hybrid Cars
    Grid charging, deep discharging | Page 2 | Honda Insight Forum

    #2 Dr Prius App, Hybrid Assistant, Techstream
    Hybrid battery diagnostic and repair tool for Toyota and Lexus
    Link at top - what OBD2 to buy
    Suggest Android versions, Apple limitations on iOS version
    Hybrid Assistant: App

    Lots of flaky OBDII dongles on Amazon Ebay
    Techstream on a laptop, try OBDii365, looks like they are sold out of the MiniVCI for under $20, Suggesting SP245 version
    Search Result: Techstream

    Techstream discussion here
    Offical TechStream software thread( settings and such) | Page 119 | Toyota Tundra Discussion Forum

    #3 Grid charger HA Cons? Expensive, build one for less than $100, hobby chargers? Cross that bridge when you come to it.
    Can I borrow your battery charger/balancer/reconditioner? | Page 7 | PriusChat
    DIY Grid Reconditioning Charger | PriusChat
    DIY harness for DIY charger/discharger | PriusChat

    Mike Dabrowsky one of the grid charger pioneers, here is his schematic for basic charger, possible HA used his build as the forerunner for HA
    http://99mpg.com/Data/Resources/downloads/gridchargerstuff/basicgridchargerv1.pdf
    Lots to unpack on Mikes site.
    http://99mpg.com/Resources/downloads/gridchargerstuff/
     

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    #3 alftoy, Mar 19, 2021
    Last edited: Mar 19, 2021
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  4. TrillingThrows

    TrillingThrows New Member

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    I should probably update that lol , I'm currently driving a 2011

    Thanks a LOT , the idea of making a grid charger never crossed my mind , and I will definitely look forward to learning about this. I would have also never figured out that S-Keith is still active on other forums always enjoyed reading his stuff.
     
    #4 TrillingThrows, Mar 19, 2021
    Last edited by a moderator: Mar 19, 2021
  5. tidesofthesky

    tidesofthesky Member

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    #1 - I'd just do a search here on the forum :)

    #2 -Techstream is absolutely necessary. Easy to pickup a mini-vci cable with techstream for dirt cheap. Generic code readers will only read the engine ECU codes, not the battery, hybrid system, brake system etc.

    #3 Hobby charger reconditioning takes forever. Grid charging is faster/easier. My understanding is that grid charging is more helpful for a weak pack whereas if you have codes and failed modules, no matter what, you'll have to replace that module- which means you'll really want to do some internal resistance measuring on the old and new modules before replacing- you can do this with a hobby charger setup.

    #4 As far as I understand, the most common reason for a failed (original) pack is that it is reaching its end of life- one or multiple modules has a failed cell. When a module begins to fail, my very vague understanding is that the other modules begin pouring their charge into the failing module, further causing that module to fail. This is why internal resistance balance is so important. I would argue this is the same reason "rebuilt" packs go bad- end of life modules and/or imbalance in the pack. Toyota starts the packs off perfectly balanced- maybe sorting thousands of modules to come up with 28 that are the most balanced. When a pack is rebuilt, it is often with a random module from another random used pack with an unknown discharge curve/internal resistance.

    My big takeaway from my hybrid pack rebuilding is that unless you have expensive equipment, do very extensive testing, and have access to a huge amount of used modules, you are basically taking a stab in the dark when rebuilding. Let me explain.

    The most important factor (imo) when rebuilding a pack is each modules internal resistance. This is something that cannot be changed and is inherent to each module. It is imperative that internal resistances of every module in a pack be as close as possible to avoid the pack pulling itself apart as explained in my response to #4. So whatever replacement modules you're adding must have the exact same internal resistance as the rest of the pack. But as a diy'er, when rebuilding a pack, at best, you might have an extra 28 modules from a 2nd battery pack you've purchased. So you could measure the internal resistance of each of those new 28 modules and compare them to the 28 modules in your old pack, then choose the best matches as replacements for the failed modules. BUT WAIT. Internal resistance is not static, it's something that varies with charge state. So NOT ONLY do you need to measure internal resistance, you need to graph it over the entire charge state on all of the modules, then overlay those graphs to figure out which modules line up well. (My understanding is that this is how a professional company would do it) And that's where it gets complicated, and why I say you are basically taking a stab in the dark. Because when measuring internal resistance at X charge state, you are just choosing a random data point and then basing your replacement on that.

    With that said, I think some hobby chargers do have a graphing function that I would 100% try to use the next time I rebuild a pack. That would definitely get you closer to having well matched modules. I really enjoyed rebuilding my pack, and I'd do it again. But I wanted to explain my understanding of why it's so common for rebuilt packs to fail after a short time. My daily driver Prius has 380k miles on it with the original battery pack. It's still going because the pack has gotten weak, but all the modules have gotten weak together. It's when you start having imbalance that you have issues (as far as I understand- there's definitely more to it than that, but that's one main cause of battery failure). And that's what the grid charger offers- an attempt to keep the pack in balance.
     
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  6. TrillingThrows

    TrillingThrows New Member

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    Thanks a lot for the detailed reply , is matching resistance really that important? I had read somewhere that matching capacity was one of the best way to screen your modules for effectiveness. Obviously the more things you can match the better , but does it really have that much of an impact as compared to just matching capacities and voltage under load? Also I have ordered techstream It hasn't arrived and I've never used it but does it really not have a graphing feature? At the very least I imagine it can give you live readings of the internal resistance which would be good enough for you to periodically write down some data points and analyze it that way vs a graph , you're really only looking at the ones that depart from the mean anyways.
    Also do you know what percentage difference would be a good cut off to establish some quality control when it comes to the variance of internal resistance? For capacity and delta V I have read that anything less than 3% variance is ideal .
     
  7. ozmatt

    ozmatt Active Member

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    steve keith is tha mann .. cheers n beers fir st. keith :)))
     
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