Prolong charger push pack over the edge?

Discussion in 'Gen 2 Prius Technical Discussion' started by dex3703, Jul 11, 2017.

  1. dex3703

    dex3703 Member

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    Hello,

    I bought the Prolong charger and reconditioned the battery. Saw improvement from 47mpg to 53mpg. Problems with the battery showing all but empty after sitting overnight resolved.

    However, since last week my mileage has dropped back to 47, and the car does not accumulate much charge when going downhill. When I put the charger on overnight, the voltage has hardly moved by morning--for example, from 223 volts to 227.

    Should I just let the charger sit for longer, or has one of the cells gone bad? No warning lights.
     
  2. SFO

    SFO Senior Member

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    How many miles on this HV battery pack/prius?

    When was your first (and last) Prolong reconditioning/balancing and at what mileage(s)?

    How many times have you reconditioned/balanced this pack?

    Did you do all three discharges at 134v, 84v and 17v?

    Do you have a way to read the voltage/resistance of the module pairs?
     
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  3. edthefox5

    edthefox5 Senior Member

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    Hard to imagine buying the prolong and not having a mini Vic to check
    Parameters. It's pretty cheap and very powerful.
     
  4. dex3703

    dex3703 Member

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    I was hoping for helpful responses like "yes, that happened to me, and here's what I had to do", or "don't worry about it, just charge it for 24 hours", instead of general scolding. I have two DMM and a source for the Techstream software.
     
  5. dex3703

    dex3703 Member

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    The car has 122k.
    I got the unit installed about two months ago and did the complete charge and discharge then.
    I can get the Techstream sw. Is there any other way to read the cells?

    I was hoping for info on how likely it is the charger damaged a cell/cells. The mileage and voltage continues to drop. Today I hooked it up again and it started at 211v.
     
  6. Raytheeagle

    Raytheeagle Senior Member

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    Did you discharge at all 3 voltages?

    You can get the Torque Pro app for your phone and read the block voltages.

    Are you seeing voltages cycling in your HSI display on the car? How much have you driven since the reconditioning? When putting the charger on, how long did you let it charge up until you got the 227 volts?

    You could always private message @jeff652 with specific questions (y).
     
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  7. SFO

    SFO Senior Member

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    Have you already inquired with @jeff652 about your current Prolong experience?

    The first time I did a full grid charge it went from 214v to 239v in about 2.5 hours (seemed rather quick compared to what I've read here), then started to fall at 1v per hour until I finally shut it down out of fear (at 236v) and put it on the discharger, then after taking it down to 134v (it bounced to 170v overnight, which I read is a good bounce back voltage) it took 21 hours to get back up to 239v, only rising about 1v per hour for the last 12+ hours.

    I've yet to take it below 134v, but will once I understand better what is going on with this particular battery.
     
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  8. dolj

    dolj Senior Member

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    Yes, you can get a OBDII bluetooth dongle and pair it with a phone/tablet app like Torque Pro (android) or Engine Link (Apple) . Both these require setting up extended capability by installing PID files.
    Can't say how likely as that depends on the initial condition of the battery before you started. But if the battery was on the edge, it is possible that the conditioning pushed it over. The good (not so bad?) news is that it was going over the edge anyway, so don't feel too bad.
    Probably an indication that at least one cell in a module is damaged. If you want to continue with the repair, get hold of Techstream or set yourself up with one of the other options and get the codes. This should point you to the block(s) that have bad modules. You will most likely need to disassemble the pack and replace any modules that are weak. Fully charge with your battery with the grid charger before disassembling (in any case) and if you can let it sit for up to a week. This will allow you to quickly verify which modules are weak by running over them a DVM. If you don't want to wait a week, use a 65 - 100 W load to test each module.

    Hope that helps.
     
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  9. jeff652

    jeff652 Senior Member

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    The charger & discharger at their peak deliver a much lower current to/from the battery than the minimum current the car ever does. It can be though of like comparing a garden hose on a slow dribble to a fire hose at various speeds. We've sold close to 3,000 systems so far and I have had one report of a reconditioning treatment causing a cell to fail. It was an old cell in a borderline pack that likely would have failed anyways.

    I don't think you hurt the battery, but I'm more curious about the fact that your voltage is not rising during the charge session. What is the current displayed on the Amp meter? Is it around 350mA or closer to zero? Can you recheck to verify that the hybrid battery cooling fan is running when the charger is connected?

    211V is completely normal for the battery. It is usually in the 205V-225V range when being used by the car. Nothing you are reporting alarms me, but I am curious about why the voltage is not rising. Give us a call at 800-589-0730 if you'd like to talk about this via phone. :) Jeff
     
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  10. dex3703

    dex3703 Member

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    Hi Jeff! I figured I'd hear from you.
    Amps are a steady .347-.350.
    Fans are all running fine.

    I put the charger back on last night. It rose from 211v to 234v over about 12 hrs. It seemed to perform better this morning, but my MPG is now down to 44.

    I'm just surprised that the bottom fell out of performance all of a sudden, though the car isn't worried about it. Should I just go through a reconditioning again? I have someone I can borrow TechStream from--would that be more instructive?

    Thanks,
    Derek
     
  11. jeff652

    jeff652 Senior Member

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    It may be time to give the pack another treatment, yes. How long has it been since the last reconditioning of the pack?
     
  12. dex3703

    dex3703 Member

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    I installed it and did the first charging mid-May.
     
  13. uart

    uart Senior Member

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    Nothing there necessarily points to the battery being bad. Many other thing can cause a drop in fuel economy. If you are basing your belief that the battery is bad purely on MPG then you need to back up a bit and start looking for more specific signs of battery failure.
    Is a more a sign of a battery in good health than one that is faulty.
     
  14. edthefox5

    edthefox5 Senior Member

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    I experienced the same thing after conditioning it would not go above 236 even after 14 hours but the battery shows major improvement though. Hardly ever goes into one purple anymore but used to really easily.
    Battery has never thrown a code and I bought the car new in 07. Car has 110k miles.

    Surprising result as I performed the discharge wrong. I did the 3 discharge levels successively and then did the charge.
     
  15. dex3703

    dex3703 Member

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    How did you do the discharge wrong?


    Posted via the PriusChat mobile app.
     
  16. dolj

    dolj Senior Member

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  17. edthefox5

    edthefox5 Senior Member

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    Yep I boned it. Just did a 3 level discharge and then one final charge. Instructions were very poor imho.
     
  18. dex3703

    dex3703 Member

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    Huh? Do you mean you didn't charge it back up between discharges?

    Posted via the PriusChat mobile app.
     
  19. dolj

    dolj Senior Member

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    Yep, not recommended, but Ed seems to have got away with it.
     
  20. dex3703

    dex3703 Member

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    To return on this, it looks like the problem was a tank of bad gas. Filling up with a new tank, the mileage returned to 52mpg and behavior is back to normal.

    Anybody seen anything like this?
     
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