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Time to rebuild HV battery...again

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Lesk_The_Glut, Jun 5, 2016.

  1. Lesk_The_Glut

    Lesk_The_Glut Junior Member

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    Hey folks. My 2006 has about 220,000 miles. The 12v battery is 3 1/2 years old.

    With the help of a wealth of info on this site, I rebuilt the HV battery in May 2015. I replaced 3 modules and took the pack through 3 charge/discharge cycles using Hybrid Automotive's grid charger and simple discharger. I also cleaned the cooling fan.
    All was fine for a month or so. Then I got the trouble lights but the obdlink I had wouldn't show the codes. I noticed a decrease in mileage and a slight hesitation upon acceleration from a stop.

    I finally got the mini vci and a win xp laptop to find the codes:
    P3000
    P0A82
    C1310

    At that time, I was unaware of the importance of detail codes. So, no more info.
    After maybe a week or so, the ICE wouldn't start and, being busy, I parked it for a while.
    About a month later, I pulled codes:
    P0AA6 with detail codes 526 and 613
    P3000 with detail code 123
    P0A82 with no detail codes but it indicates "hybrid battery pack cooling fan 1 performance/stuck off.

    I connected the grid charger and the HV fan engaged, as it should. I cleared codes and took a drive, while monitoring with Techstream. I watched the fan modes climb to 6, during driving and idling, over about a half hour period. Not sure if this means anything, but I've read that people can hear the fan from the drivers seat when it's running at 3 or 4- I forget which. Well, at 3, or maybe 4, I couldn't hear it. Even standing at the rear door, with my ear against the vent. Though, there was ICE and parking lot noise to contend with. Once it got to 6, I could hear it easily.

    Battery health, at that time: With fan at 6, temp of batt tb1 through tb3 was 51.6 c, 56.5 c, 50.4 c.
    Battery blocks voltage ranged from 16.05 to 16.15. Internal resistance ranged from .024 to .026 ohms.

    Out of necessity, I've been drivng this car again, for months now. The lights came back and the codes were still P3000 with detail code 123, P0A82 with the addition of C1310. I don't see a detail code in the same place in tecgstream as the others but there is a field that says "detailed freeze DTC 156". I assume this may be a detail or sub code. Nothing has been preventing me from starting the car. But months ago there had been 2 occasions when, after having driven several miles and parked for a short time, then taking the freeway home, the car would idle high going up an overpass. On these occasions, the MFD shows a low SOC with only one purple bar. The first time this happened, it took around 10 miles before the SOC would creep up. The second time, I had it on cruise control and, while ascending a grade, the car jerked violently and acted as if I were flooring and letting off the gass in quick succession, about 4 times. I disengaged cruise control and took hills more slowly. The high idle up the hills backed off as the battery SOC increased. This time the SOC started in increase within a few minutes, as I would expect normally. I imagine that the electric motor was turning off and on, when the car was jerking, due to a low SOC.

    These symptoms cleared up in a few days, apart from the hesitation on accelerating from a stop, and I've been driving it ever since. With a new job, both time and money have been tight and I'd meant to look into the codes further and wish that I had. A few weeks ago, I noticed the car had major difficulty accelerating. I'll floor it and it barely moves, taking several seconds longer than it should to get up to speed. The SOC is stuck at 1 purple bar. I got the car home and turned it off. When I turned it back on, the SOC increased very quickly, only once. I now can't replicate that. The SOC simply will not go above one bar. Another odd thing. When I'm creeping down the road, at say, 25mph, and I let off the throttle, the car just keeps moving as if cruise control is engaged.

    Current codes:
    P3000, detail code 2: 123
    P0A80
    P3022, battery block 12 becoms weak
    C1259
    C1310, HV system malfunction. Again freeze frame data says detailed freeze DTC has a value of 156.

    I could swear that I only had 1 bar when I pulled these codes but freeze frame data indicates 30% SOC.
    Batt Temps: TB1 is 104F, TB2 is 103.3F, TB3 is 104.9F
    Battery Block Vol ranges from 17.30 to 17.45, with the notable exception of, of course block 12. It was 17.75
    I pulled info a few minutes later and block 12 was even further away than the others. While the others ranged from 15.44 to 15.84, 12 was 13.84, a whole 2 volts off! But what confuses me is that, while the first test today showed block 12 was almost half a volt higher than the lowest block, and the second test showed 12 a full 2 volts apart from the other blocks, the second test had all of the other blocks varying by about half a volt. Not sure if I should worry about that. I hope that made sense.

    So, it appears that I should look into changing at least 1 module in block 12. But I wonder what some of these other codes are telling me. Is there another issue that is causing these battery issues?

    Thanks
     
  2. S Keith

    S Keith Senior Member

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    These are secondary failure indications associated with the bad battery.

    A failed cell can also trip the high voltage limit. A "becomes weak" code will frequently see that behavior... maxV under charging and minV under load.

    The 0.4V spread between 15.44 and 15.84 is concerning. You likely have multiple modules significantly out of balance and potentially failing.

    Good luck,

    Steve
     
  3. JC91006

    JC91006 Senior Member

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    If you've cleaned the cooling fan already, it may need to be replaced now. Heat will damage your modules if it is not cooling properly
     
    S Keith likes this.
  4. Lesk_The_Glut

    Lesk_The_Glut Junior Member

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    Thing is, I think I hear it running more since the first rebuild. But it may be that I'm paying more attention to it.
     
  5. JC91006

    JC91006 Senior Member

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    You may be able to hear it running, but it might not run consistently or slower than normal. Triggering a code. I tested another member's car this week with the same dtc and I heard the fan run, but it definitely was not running at full speed
     
  6. bisco

    bisco cookie crumbler

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    you can monitor the cooling fan speed.
     
  7. Lesk_The_Glut

    Lesk_The_Glut Junior Member

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    I pulled the battery and load tested the modules.

    Module / pre load voltage / 30 sec load / difference
    1---------- 7.46 ----------- 7.31 ------------ .15
    2 ------------ 7.47 ------------ 7.31 ------------ .16
    3 ------------ 7.48 ------------ 7.3 ------------ .18
    4 ------------ 7.46 ------------ 7.29 ------------ .17
    5 ------------ 746 ------------ 7.27 ------------ .18
    6 ------------ 6.2 ------------ 5.9 ------------ .3 ********
    7 ------------ 7.54 ------------ 7.36 ------------ .18
    8 ------------ 7.41 ------------ 7.22 ------------ .19
    9 ------------ 7.44 ------------ 7.26 ------------ .18
    10 ------------ 7.44 ------------ 7.27 ------------ .17
    11 ------------ 7.53 ------------ 7.35 ------------ .18
    12 ------------ 7.44 ------------ 7.26 ------------ .18
    13 ------------ 7.44 ------------ 7.25 ------------ .19
    14 ------------- 7.44 ------------ 7.26 ------------ .18
    15 ------------ 7.43 ------------ 7.25 ------------ .18
    16 ------------ 7.44 ------------ 7.26 ------------ .18
    17 ------------ 7.45 ------------ 7.28 ------------ .17
    18 ------------ 7.45 ------------ 7.27 ------------ .18
    19 ------------ 7.44 ------------ 7.26 ------------ .18
    20 ------------ 7.49 ------------ 7.3 ------------ .19
    21 ------------ 7.47 ------------ 7.29 ------------ .18
    22 ------------ 7.46 ------------ 7.29 ------------ .17
    23 ------------ 7.47 ------------ 7.3 ------------ .17
    24 ------------ 7.48 ------------ 7.3 ------------ .18
    25 ------------ 7.49 ------------ 7.33 ------------ .16
    26 ------------ 7.48 ------------ 7.32 ------------ .16
    27 ------------ 7.51 ------------ 7.36 ------------ .15
    28 ------------ 7.45 ------------ 7.3 ------------ .15

    6 is bad but all else looks good to me. Any opinions the benefits of performing an internal resistance test, as well?
     
    #7 Lesk_The_Glut, Jun 28, 2016
    Last edited: Jun 28, 2016
  8. JC91006

    JC91006 Senior Member

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    Swap out the module and balance up the pack......good to go again
     
  9. Lesk_The_Glut

    Lesk_The_Glut Junior Member

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    Wish I wasn't in CA. If memory serves, the lit for my Hybrid Automotive grid charger says not to use above 100 degrees. I wonder if I'll complicate things by charging in spurts, during evening hours.
     
  10. JC91006

    JC91006 Senior Member

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    You don't have to charge right away. You can defer the balance until it cools a bit.

    Do a top off charge for 12 hours, evenings, then wait and balance later. Won't harm it
     
  11. S Keith

    S Keith Senior Member

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    You already did an IR test. You measured voltage drop under a load.

    I'm with JC. Replace module and balance charge.

    Like JC says. Won't hurt nothin... Total time is more important than continuous time. Best to do on consecutive days. Total charge time will be a little longer due to self-discharge working between charges, but it's not a big deal.
     
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  12. strawbrad

    strawbrad http://minnesotahybridbatteries.com

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    Techstream starts the module count opposite the battery computer. It appears you started your count at the battery computer. So your #6 is in Techstream's block #12.

    Brad
     
    #12 strawbrad, Jun 29, 2016
    Last edited: Jun 30, 2016
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