1. Offline

    Jsnake49 New Member

    Member Since:
    Nov 30, 2011
    Posts:
    3
    Likes Received:
    0
    Location:
    Rogers, Arkansas
    Your Vehicle Year:
    2002 Prius
    Model:
    I
    Hello all! I am a newbie to the site but have been using this site for TONS of useful information but I'm in need of some more hoping for some help!

    I will start with the whole story... I have a 2002 Prius I recently purchased with the knowledge it was seemingly in need of an inverter. (It would intermittently fail). After further diagnosis I confirmed this and purchased a salvage unit from ebay and installed it. (I should say I am a certified mechanic but have minimal experience with hybrid vehicles.) This salvage unit turned out to also be bad, as it would not start the ICE. The car was able to briefly drive on electric power only. And after a very short trip up the street (uphill) the HV battery has been run down too low. SOOO, after reinstalling the original inverter, the ICE attempted to start but without enough power in the HV battery it was only able to crank the engine for a brief couple of seconds before flashing lights and popping codes for battery failure.

    Now that I've explained my situation... What I need to do is get enough charge into the HV battery to get the ICE to start and take over charging it the rest of the way. I know the battery is still good because before I started the repair the vehicle got 52 mpg on the long trip home.

    I understand the easiest possible only safe way, to charge it is to disassemble it, and charge each module individually. I also understand this is done with the use of an RC charger... I am not familiar with using these but if someone can recommend a good one it will point me in the right direction. Thanks in advance for the help!
  2. Offline

    seilerts Battery Curmudgeon

    Member Since:
    Mar 7, 2010
    Posts:
    3,325
    Likes Received:
    1,434
    Location:
    Santa Fe, NM
    Your Vehicle Year:
    2005 Prius
    Model:
    N/A
    I use SuperMate DC6. However, you can use a 12V battery charger and charge 2 at a time in series. A dumb 12V charger is better, like an analog version that will do 10 amps, to get the charging voltage up to around 15V. You are only looking to add 1 amp hour or so. Do you have an old wheel cart-type 12V charger? I've got a Schumacher 10/40/200 with a mechanical timer -- I love it, completely old school -- a setup like that is what you could use.
  3. Offline

    Jsnake49 New Member

    Member Since:
    Nov 30, 2011
    Posts:
    3
    Likes Received:
    0
    Location:
    Rogers, Arkansas
    Your Vehicle Year:
    2002 Prius
    Model:
    I

    I've considered doing this with a 12 volt charger which I have several of. My hesitation with this is I thought all the modules had to have very similar charge or else the computer would recognize a difference in voltages as a bed cell/module and pop codes. Have you ran into this? How do you balance the charges between all the modules evenly? How exactly/what did you use to hook to modules together in series to charge them? Thanks for your help!!
  4. Offline

    seilerts Battery Curmudgeon

    Member Since:
    Mar 7, 2010
    Posts:
    3,325
    Likes Received:
    1,434
    Location:
    Santa Fe, NM
    Your Vehicle Year:
    2005 Prius
    Model:
    N/A
    Disconnect all of the bus bars on one side -- the side with the sense wires. If you have linesman's gloves and insulated tools, use them for this step, as you have 200V at your fingertips. Once off, you have 19 battery pairs.

    The computer will be unhappy if it detects more than 1.2V difference from the highest to lowest pair. It can resolve imbalances that are smaller than that. You shouldn't have a problem, unless you have a bad module, which is possible. If you like, you can take voltage readings of all 38 modules and post them here for comment.

    The problem that you face is this: if you are putting on a partial charge, you can only do this in pairs, because that is how the battery computer manages the string. It can resolve a charge imbalance from one pair to the next, but it cannot resolve an imbalance inside the pair, and that can lead to the higher module being overcharged or the lower module having a cell reverse.
  5. Offline

    jdenenberg EE Professor

    Member Since:
    Nov 21, 2005
    Posts:
    2,300
    Likes Received:
    607
    Location:
    Trumbull, CT
    Your Vehicle Year:
    2004 Prius
    Model:
    N/A
    A SuperMate DC6 can be used to carefully discharge those modules with higher voltages to match the voltage on the lower charged modules (one at a time, Seilerts has 14 of them :) ). Use a separate digital voltmeter to monitor the module being discharged and remember that the module voltage will bounce back up a bit when the discharging current is stopped.

    JeffD
  6. Offline

    seilerts Battery Curmudgeon

    Member Since:
    Mar 7, 2010
    Posts:
    3,325
    Likes Received:
    1,434
    Location:
    Santa Fe, NM
    Your Vehicle Year:
    2005 Prius
    Model:
    N/A
    Here's the setup that I was describing. A 10A analog 12V charger will converge to 0A at around 15.5V. I tried 40A for grins, but it made the charger trip.

    [IMG]

    [IMG]
  7. Offline

    Jsnake49 New Member

    Member Since:
    Nov 30, 2011
    Posts:
    3
    Likes Received:
    0
    Location:
    Rogers, Arkansas
    Your Vehicle Year:
    2002 Prius
    Model:
    I
    Thank you so much for this useful information! I have ordered a Supermate DC6 to charge the battery. This is capable of providing adequate voltage to charge the modules in pairs? 15 volts @ 1 amp? Or do I need to charge them one at a time and ensure they are balanced before reinstallation?
  8. Offline

    seilerts Battery Curmudgeon

    Member Since:
    Mar 7, 2010
    Posts:
    3,325
    Likes Received:
    1,434
    Location:
    Santa Fe, NM
    Your Vehicle Year:
    2005 Prius
    Model:
    N/A
    First, check all terminal voltages. If non are more than 0.1V off the average, then you should be good to go. If you have one or more that is 1.2V less than the others, then they should be replaced.

    The charger can put out 5 amps or 50W, whichever comes first. Since you have a smart charger, you do not need to do this pair-wise. Simply add the same amount of charge to each module. I suggest 2500 mah. You can set this in the user defined settings. Then go back to the NiMH charging menu, and select 6S, 5 Amp charge, and turn it loose. You will then need to move the charger up to the next module every half an hour.
  9. Offline

    yankkesrule Junior Member

    Member Since:
    Jan 7, 2013
    Posts:
    17
    Likes Received:
    2
    Location:
    Masshole
    Your Vehicle Year:
    2001 Prius
    Model:
    N/A
    Hi. Sorry to bring an old thread from the dead but I've recently started cycling/checking my battery. I'm using a Dynam DC6 charger. I have one question I wasn't able to find. What should I set the delta peak shut off to? I'm using "Default" which is 7mVbut I don't know if that is the best option.

    Thanks
  10. Offline

    bwilson4web 03 and 10 Prius

    Member Since:
    Nov 25, 2005
    Posts:
    11,498
    Likes Received:
    3,269
    Location:
    Huntsville AL with 2003 Prius
    Your Vehicle Year:
    2010 Prius
    Model:
    III
    Hi,

    You'll need to have multiple protections:
    • ~5 mv/cell - threshold
    • ~100F - temperature limit
    • 3.5 Ahr - initial charge limit (unknown, used cells)
    If they charge to 3.5 Ahr and not the other limits, let them sit for a day or so before cycling that one again. Up the limit and try the next module.

    Bob Wilson
  11. Offline

    yankkesrule Junior Member

    Member Since:
    Jan 7, 2013
    Posts:
    17
    Likes Received:
    2
    Location:
    Masshole
    Your Vehicle Year:
    2001 Prius
    Model:
    N/A
    Thanks Bob. That translates to 3500mAhr right? Why so low? Just to be safe since as you said they are unknown?
    What amperage would you recommend I charge at. I've seen from other threads-
    5a charge
    .7 discharge to 6v
  12. Offline

    bwilson4web 03 and 10 Prius

    Member Since:
    Nov 25, 2005
    Posts:
    11,498
    Likes Received:
    3,269
    Location:
    Huntsville AL with 2003 Prius
    Your Vehicle Year:
    2010 Prius
    Model:
    III
    Correct. I've seen weak modules, especially after the 3d cycle, lose the dV/dt notch. Resting 24 hours seems to bring it back. So I typically like to see two charge/discharge cycles, initial survey. Then two more after tweaking any charger parameters as needed.
    Good, fast, cheap . . . pick two. Personally, I like the charge to be 1/10th estimated C . . . close to 10 hours. But then I have enough inventory and time to be patient. Still:
    • charging is exothermic - they get warmer
    • resistance heating is the current squared - also leads to warming
    My recommendation is experiment and try to make it match your ordinary schedule.

    Bob Wilson
  13. Offline

    yankkesrule Junior Member

    Member Since:
    Jan 7, 2013
    Posts:
    17
    Likes Received:
    2
    Location:
    Masshole
    Your Vehicle Year:
    2001 Prius
    Model:
    N/A
    Well, I would definitely pick good/cheap. I've got another car to drive in the meantime. So I'm not in a particular rush. Though of course I don't want it to take too long. My plan is to try and get some more use out of this pack. If all goes well, I will try to get my hands on a couple 2nd gen packs and rebuild with gen2 cells. I'm running 4 chargers.
    So do you think 5a is too much?
  14. Offline

    bwilson4web 03 and 10 Prius

    Member Since:
    Nov 25, 2005
    Posts:
    11,498
    Likes Received:
    3,269
    Location:
    Huntsville AL with 2003 Prius
    Your Vehicle Year:
    2010 Prius
    Model:
    III
    My interest was in module capacity measurements, the first full discharge after an initial charge. That typically is done at 1/10th C. So I soon learned used modules have significantly decreased capacity, often in the 2.5Ahr range or less if any. But these were experimentally determined. But I'm not trying to force any given protocol as much as 'this is what I used'.

    Try the 5A, experiment, and let us know how it works.

    Bob Wilson
    yankkesrule likes this.
  15. Offline

    yankkesrule Junior Member

    Member Since:
    Jan 7, 2013
    Posts:
    17
    Likes Received:
    2
    Location:
    Masshole
    Your Vehicle Year:
    2001 Prius
    Model:
    N/A
    I've already run through a few cells. You are right on. I had already run 4 cells through 3 cycles @ 5A/ .7A.
    final discharge #s
    #1 cell 2434mAh
    #3 cell 1993 mAh
    #5 cell 2164 mAh
    #7 cell 4723 mAh

    I've been doing every other cell to help manage heat. These have obviously been disappointing numbers.
    thanks for the responses.
  16. Offline

    Prius_Cub Member

    Member Since:
    Feb 12, 2013
    Posts:
    112
    Likes Received:
    33
    Location:
    Radford, VA
    Your Vehicle Year:
    2008 Prius
    Model:
    II
    Any progress on reconditioning your modules? I'm interested to see how much more usable capacity you get after a few cycles.
  17. Offline

    yankkesrule Junior Member

    Member Since:
    Jan 7, 2013
    Posts:
    17
    Likes Received:
    2
    Location:
    Masshole
    Your Vehicle Year:
    2001 Prius
    Model:
    N/A
    Yes. Here is what I have right now.

    Cell# final dischargemA / charge mA after 3 cycles at 5A charge, .7 discharge
    1) 2434 / 4281
    2) 2001 / 3190
    3) 1993 / 3573
    4) 2198/ 3819
    5) 2164/ 3818
    6) 1884/ 3471
    7) 4723/ 6511
    8) 1847/ 3328
    9) 1822/ 3500
    10) 2073/3696
    11) 1916/ 3458
    12) 1752/3694
    13) 1673/3500
    14) 1655/3664
    15) 1664/3328
    16) 2096/4109
    17) 1606/3207
    18)1788/3328
    19) 1737/3204
    20) 1535/3451
    21) 1700/3453
    22) 1828/3814
    23) 3780/5404(JUST REPLACED THIS ONE)
    24)1926/3939
    25)3079/5755
    26)1693/3500
    27)2129/4188
    28)1856/3816
    29)2022/3943
    30) 1877/3776
    31) 4356/6204
    32) 1935/3451
    33) 1780/3907
    34)1881/3696
    35)2029/3653
    36)1963/3583
    37)2038/4062
    38)2215/4273

    Aside from the one I marked as "new", there are a few more that have notably better numbers, those have been replaced within the past year. (I replaced one cell with no charging/balancing. It lasted almost a year then lights came back, replaced 2 more cells and it only lasted a day which is why I'm now doing all this.

    I've re-cycled a few that had particularly low numbers with 2-400mA increases.(already reflected in these numbers) I'm re-cycling the ones will less than 2000mA discharges right now.
    Any input is appreciated.
  18. Offline

    Prius_Cub Member

    Member Since:
    Feb 12, 2013
    Posts:
    112
    Likes Received:
    33
    Location:
    Radford, VA
    Your Vehicle Year:
    2008 Prius
    Model:
    II
    Are you using gen 1 modules or gen 2? I'm getting some gen 1 modules just to experiment with and learn from and possibly make a battery pack for my ebike with.

    Sent from my HTC Evo 3D
  19. Offline

    bwilson4web 03 and 10 Prius

    Member Since:
    Nov 25, 2005
    Posts:
    11,498
    Likes Received:
    3,269
    Location:
    Huntsville AL with 2003 Prius
    Your Vehicle Year:
    2010 Prius
    Model:
    III

    Ahrcell
    47237
    435631
    378023
    307925
    24341
    221538
    21984
    21645
    212927
    209616
    207310
    203837
    202935
    202229
    20012
    19933
    196336
    193532
    192624
    191611
    18846
    188134
    187730
    185628
    18478
    182822
    18229
    178818
    178033
    175212
    173719
    170021
    169326
    167313
    166415
    165514
    160617
    153520

    This "whack a mole" module replacement approach risks the good modules from heating by the adjacent, failing modules.

    Bob Wilson
  20. Offline

    yankkesrule Junior Member

    Member Since:
    Jan 7, 2013
    Posts:
    17
    Likes Received:
    2
    Location:
    Masshole
    Your Vehicle Year:
    2001 Prius
    Model:
    N/A


    I'm with you Bob. The first time around was just an experiment. I bought the car knowing it had a bad battery. Just for giggles I replaced the bad cell just to see what would happen. I was surprised when it lasted so long. I kept driving the car with no issues. Then the car sat for a few months, I started her back up, made it about 2 miles and the dash lit up like a christmas tree. So I took it back out, found 2 bad cells and threw 2 more in and well, here I am.

    I'm putting more effort in now as a learning experience. If I'm able to make it work I hope to rebuild in the future with Gen2 cells. I work on Toyotas for a living and I consider myself pretty good at what I do. But electrical engineer I am not. As you already know, we don't play with cells at the dealer.

Share This Page