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Gen 1 HV BATTERY REBUILD WITH 2G CELLS

Discussion in 'Generation 1 Prius Discussion' started by UKCLASSICPRIUS, May 15, 2010.

  1. UKCLASSICPRIUS

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    YES Bob, Your work was one of the 1st posts I ever bumped into after getting the prius!

    I like the detailing, Its more then digestable information...

    (*I do always revert to it whilst having a cup of tea!)

    I got to Take apart the NHW11 battery today, & can say it was nice to see How it was all Put together...

    I have been looking into chargers, & my own, I have just read in my charger manual, That it charges & discharges, & also has a Delta Peak function (assume thats DV detecting function right?)

    BUT Mine wont tell me the Ahr capacity?

    Would I be able to do this manually?

    Should I try charging some Nhw11 cells, to see start eeing some results?
     
  2. brad_rules_man

    brad_rules_man Hybrid electric revolutionizer

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    Ok, I'm now following this thread. I just want to say kudos to you for taking this on. I can't wait to hear more. I now have a gen 1 Prius and I am quite worried about the battery. I know enough that if I see what you are doing here, maybe I can do this too should the need arise. :)
     
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  3. bwilson4web

    bwilson4web BMW i3 and Model 3

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    You may get away w/o Ahr capacity but you're blind to the health of each module ... their capacity. So you might wind up using a weaker module. However, the dV is worth testing if you can identify a weak, 'sacrificial' module to test with.

    Making an Ahr meter needs: (1) known load; (2) clock and; (3) voltage limiter (to avoid discharging under 1 V/cell.) I've tried similar techniques manually . . . think about watching paint dry. It is a waste of human time and you'll always have to make a biology break at the wrong time.

    Bob Wilson
     
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  4. UKCLASSICPRIUS

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    Thank you for your interest, & your help in Building my Confidence!:D
     
  5. UKCLASSICPRIUS

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    Bob I have yet to give you a detailed reply! about charging / chargers, etc... (Not ignoring you)

    for now, I have taken apart all the modules from all batterys, Ready for testing & recording all relevant info..

    in a bit..
     
  6. UKCLASSICPRIUS

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    Hi (yes it has been a whilst) Been Shopping! :cool:

    I have bought 2x chargers in helping me out with this topic:

    Both are:

    A Ripmax Pro peak Super nova

    http://www.ripmax.com/Images/PDF_Files/Instructions/Chargers/SuperNova250S_Manual_LR.pdf

    & a Ripmax Pro Peak Prodigy II (re-badged as a multiplex (multicharger LN-5014)[FONT=ArialBlack,Italic][FONT=ArialBlack,Italic]
    [/FONT][/FONT]& hyperion (e0s51) aswell!

    O-IP2801 Ripmax Pro-Peak Prodigy II Charger 1-14Ncd /1-5Li [O-IP2801 Ripmax Pro-Peak Prodigy] - £59.99 : B & H Models, Your Online Hobby Store

    (technical specifications here: http://www.battlepack.com/hpimages/eos5i-manual.pdf#search=%22hyperion%20eos%205i%20instructions%22)

    I hope these will help me Bob, As I never like the thought Of watching paint Dry!

    What you recon?
     
  7. bwilson4web

    bwilson4web BMW i3 and Model 3

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    It looks like they'll do. Minor, it would be nicer if they had a thermal probe to avoid overheating and did not include a warning against automatic charge/discharge of NiMH batteries. Still, they have limits including peak charge detection ... the most critical function and won't over discharge. If I read the instructions right.

    You're at the 'bleeding edge' so use boards to clamp the sides of a couple of modules and give it a go. Take good records and let's see what happens. Make sure the modules are on a safe, plastic tray or surface. We don't want any KOH to leak onto a valuable surface.

    Bob Wilson
     
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  8. UKCLASSICPRIUS

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    Yes Bob nearly there!

    "I was thinking of using THE 2g battery case ends, (that are made from plastic) & put a Module in between (Sandwiched) in a vice!"

    NOT as Good as your Capacitive load sensor, BUT still an idea Huh?

    I doubt the 2g modules will strecth, as the nhw11 modules, As they have the metal sides!
     
  9. bwilson4web

    bwilson4web BMW i3 and Model 3

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    That should work.

    I could find no resistance through that shiny material. I'm pretty sure it is some sort of mold release, not a structural plate. Take a magnifying lense and see what you find.

    You might consider in the first modules making a log with time vs voltage and current during the charge. My favorite trick is to use a semi-log scale between measurements:
    seconds
    10
    20
    50
    minutes
    1
    2
    5
    10
    20
    40
    hours
    1
    2
    . . .
    If you record the data in a spreadsheet, you can have a plot that updates during the charge. This will give you an idea of progress and how soon it is likely to stop.

    GOOD LUCK!
    Bob Wilson
     
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  10. hobbit

    hobbit Senior Member

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    The shiny coating on the 2G modules is for better heat dissipation,
    as that's where the airflow comes through the pack. The plastic
    cases don't contain pressure any better, and overcharging has
    well known effects.
    .
    _H*
     
  11. bwilson4web

    bwilson4web BMW i3 and Model 3

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    I couldn't find any evidence of conduction. Any idea of what it might be?

    Bob Wilson
     
  12. UKCLASSICPRIUS

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    I also forgot to mention, That when I was doing my shopping for chargers, I could not Help myself BUT to get a Proper Digital multimeter (Craftsman Autoranging multimeter), As I was always scratching my head with my older ones, Leaving me clueless...

    Since then there are So many corrections I need to make Already! What Do I do, Go back to each of my threads & Write down CORRECTION? Dont want peoples posts to go Mis-understanded.

    Here are some Accurate Laest / Figures I have pulled out:

    The 1st replacement 2G battery I bought from a 2007 model (*of Which I Named the cells B1-28), which I was kind of dissapointed about = was NOT that bad atall! (minus the corrosion at the busbars pictured earlier this thread)

    All the 28 modules are Reading 7.61v Constantly, (Not a Fluctuation present!)
    Totaled to: 214v (& thats with the packs being stored with me & the salvage yard!)

    The second 2g HV battery I got, from a 2006 model (Named Cells C1-28, was a bit more charged up), BUT the Voltages were not Constant & DID fluctuate as follows:

    All of the modules apart from Those lised below are reading: 7.71v all the way

    The Modules that were not constant had a voltage of: (

    c4, c5, c8, c26, c27 = 7.72v
    c2, c3 = 7.73v
    c28 = 7.75v

    Making the total voltage: 216v for this HV Pack, (& thats stored with me & the salvage yards)
     
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  13. UKCLASSICPRIUS

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    I have also been trying to do a LOAD/stress test of a Module, Can you please advise me of my readings, Are they correct as in, Am I reading the Cell Voltage under Load/stress correctly?

    (I am using a 12v Car air pump compressor as previously discussed)

    I used Module c28 which was reading 7.75 volts (static = No load)

    Upon connecting & running the compressor from the module, I then reconected My multimeter & read the same reading again (this time with LOAD)

    & the result was : 7.63volts under load (compared to the 7.75volts without load)

    That makes the difference: 0.12v drain the module (IS this the Correct way of measuring the STRESSED OUT modules? & the compressor usage?

    Whats acceptable & whats not? what are the tolerances?

    *Once I know I am doing this RIGHT, I shall Test the other 55 modules, (& then the other 38 from the 1g battery for the record)

    Thanks alot...
     
  14. bwilson4web

    bwilson4web BMW i3 and Model 3

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    The standard load test is measured in Amp-Hours. We put a load on the battery and measure how long it takes to come down to a standard, stop voltage, say 1 V. Now if I remember, your chargers have a controlled discharge that stops at 1 V. per cell. This is the safest way to measure how long it takes to bring the battery charge down to 1 V. I think your unit sends a beep but better still, would be if it reports the time and current, the Amp-Hour.

    The Amp Hour is the product of the amps times the time in hours. For example:

    • 1 Amp for 1 hour -> 1 AHr
    • 2 Amp for 1/2 hour -> 1 AHr
    • 3 Amp for 1/3 hour (20 minutes) -> 1 AHr
    • 4 Amp for 1/4 hour (15 minutes) -> 1 AHr
    • "x" Amp for "y" hour -> x*y Ahr
    There is an equivalent charging Amp-Hour. It is simply how long it takes to put a known charging current into the battery until the high voltage cutoff. Again, the automatic charger circuit is your friend and safety factor.

    Please put the compressor load aside. Although you can measure the time it takes to discharge a module by: (1) measuring the current through the compressor and; (2) measure the run-time to 6 V. (aka., 1 volt per cell). This is labor intensive because when the voltage starts to drop, it is fast. Without an automatic stop, it is easy to miss the mark and going too low is a BAD thing.

    When a six cell, battery is over discharged, the weakest cell will discharge first. But if the discharge current continues flowing, the weakest cell is reverse charged . . . only it really isn't. It gets permanently damaged.

    The compressor was a reasonable load when you didn't have a smart charger with controlled discharge. Learning to use the new tool will be your best bet.

    You have the right approach, measuring the Amp-Hour capacity of the modules. But the existing, state of charge is unknown. The right procedure:

    1. Discharge to standard 1 V. per cell or 6 volts. Use the discharge to bring them down to a common starting point.
    2. Charge to the cutoff voltage and measure the time at a given current. A charge rate of 3 amp should take a little over two hours to fully charge a module. The time variation is the variable.
    GOOD LUCK!
    Bob Wilson
     
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  15. UKCLASSICPRIUS

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    Ok Bob! Understood!

    I have been Getting Jiggy, with the pro peak Supernova charger, with some other batteries I have lying around, Not all that amused to tell you the truth.. Or its my batteries are Duff?

    Can I ask:

    @ What rate of amps shall I discharge the batteries to? & Would 1.0amp Discharge current = 6 volts per module ?

    & IF I can confirm its a 3amp charge current I need to charge these modules!

    Also a TAD confused, As My charger asks me the TOTAL BATTERY CAPACITY, when setting up a charge, & the MAXIMUM setting is Only 5000mah , Compared to the 6.5ah Capacity?

    What am I thinking wrong?
     
  16. bwilson4web

    bwilson4web BMW i3 and Model 3

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    You have the right attitude and using smaller, more 'disposable' batteries to learn the tool is the right approach. It is so much easier to 'blow up' a small, 'affordable' battery first. <grins>

    Anything from 0.5-6.5 A works. In theory, you want to use 6.5 A, which is 1 C ("C" is the Ahr capacity). But in practice, I like to use a faction to slow things down.

    Use what you've got and see what happens. With my 989 charger, it shuts off automatically when the charge exceeds the set point plus 20% (an undocumented 'feature'.) It is very likely that your used modules may not have the rates 6.5 Ahr since they have been in service.

    Use cautious 'common sense' and go deliberately. As you get the first ones done, you'll have a baseline and can increase the charge and discharge currents. You are doing it right!

    Bob Wilson
     
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  17. UKCLASSICPRIUS

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    (*Thanks for the Fast reply Bob!)

    YES!!!

    (I have tried my 900mah, 8 cell, 9.6v nicads , & my 2400mah, 5 cell, 6v Nimh's)

    BUT Now have moved onto:

    modules (named a1-10 ) the 1st 5 pairs closest to the ecu, & I was shocked to find out that with a Proper autoranging multimeter readings were: (but only of the 1st ten cells I have to experiment with me, the other 28 are at my dads house)

    Modules a5 to a8 had broken down, I.e.= had voltages of 3v & under..

    these modules are are the last 2 pairs from the 1st SPLIT/half of the battery on the busbars HV bearing in mind these are the closest to the battery splitting fuse (orange saftey tab)

    the other pairs a1 to 4 & a9 & a10 Still are holding thier voltage's of above 7.8volts!

    (* I have yet to check readings from the remaining cells named a11-38)
     
  18. UKCLASSICPRIUS

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    Just done my 1st charge, (Which BONGED out Because of an Input low voltage, Caused by my 12v Rechargable power supply)

    But heres the statistics the charger has given me:

    Info regarding battery charger ASKED: (I set up)

    battery type: Nimh
    cells: 6
    battery capacity (5000mah) is the max I could put in!
    charge rate: 3a
    discharge rate: 2a

    Error gave: input low voltage
    Info regarding battery/charge I got back: from saved LCD sceen

    charged: 1126mah for time 0:22:31
    discharged: 0mah time 0

    charge voltage: 8.946v peak voltage 8.94 average voltage
    input voltage

    discharge voltage: 0v discharge start voltage. 0v discharge cutoff voltage

    also input & output voltage of charger (inputs & outputs)

    12.5v voltage input 8.946 voltage output!


    A Very Smart charger indeed!

    Just need a Proper Power pack, other then my 12v hobby pack, Or a 12v car battery, I doubt theres much these can do for me, with the amount of prius modules I have to charge & discharge!
     
  19. bwilson4web

    bwilson4web BMW i3 and Model 3

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    I would cut the amps to 1/3d, shooting for a one hour cycle. Hit the same module a couple of times to see if you can get some usable discharge Ahr.

    Welcome to my world!

    Don't worry too much about the ones already below 6 V. That was probably 'self discharge' so it is not time to write them off. But you're well in the club. <grins>

    GOOD LUCK!
    Bob Wilson
     
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  20. UKCLASSICPRIUS

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    Hi again Bob, Just to clarify:

    Are you suggesting I use a Charge current of 1a? & charge a charged module a few times?

    & then do discharge?