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Using Prolong - After Discharge/Charge Cycle - Before Driving, Should I Slightly Discharge?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by jerrydelrey, Oct 21, 2020.

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After reconditioning and before driving, should I discharge the battery slightly?

  1. Yes, slightly discharge before driving

    1 vote(s)
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  2. No, keep it fully charged before driving

    1 vote(s)
    50.0%
  1. jerrydelrey

    jerrydelrey Member

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    I just got a Prolong charger/discharger Kit for my 2010 Regular Prius.

    My first cycle of charge/discharge/charge, the end voltage was 236V. After sitting overnight, I drove it to work. I think the first 4-5 miles was very detrimental.

    Here is my reasoning. I was monitoring my battery with Dr Prius. I notice the car didn’t know the SOC right away. The car kept charging the battery for about 4-5 miles.

    Because the cells were at full capacity and being charged rapidly, the temps were higher than they normally were in the morning +110F (normally 90-100F). And the Voltage Indicator was constantly turning red!

    In my minds eye, I was imagining the cells being overcharged and venting!

    Next time around I’m thinking of discharge slightly around (225-230V).

    What do you guys think?
     
    #1 jerrydelrey, Oct 21, 2020
    Last edited: Oct 21, 2020
  2. Raytheeagle

    Raytheeagle Senior Member

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    You can always run the AC a bit once you start your Prius;).

    That'll reduce the SOC:).

    And in Hawaii, you might need the AC anyway(y).
     
    #2 Raytheeagle, Oct 21, 2020
    Last edited: Oct 21, 2020
    jerrydelrey and GrGramps like this.
  3. jerrydelrey

    jerrydelrey Member

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    Yeah, I should have stopped and ran the A/C with it in Neutral. Just to drain the battery a little.
     
    #3 jerrydelrey, Oct 21, 2020
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  4. ASRDogman

    ASRDogman Senior Member

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    Did you wait a while before starting/driving the car after charging?
    I believe you are supposed to let it sit for a period of time for it to cool, and level off?
    Isn't it supposed to sit at the "full charge" for a period of time to get rid of the
    crystalizing in the cells?

    Did you read through the instruction from Prolong?
     
    #4 ASRDogman, Oct 21, 2020
  5. jerrydelrey

    jerrydelrey Member

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    Yes, overnight. Approx 10 hours.
     
    #5 jerrydelrey, Oct 21, 2020
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  6. vvillovv

    vvillovv Senior Member

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    In my mind - there is nothing wrong with discharging back to nominal after final cycle. Voltage is really high at cycle end and drops really fast comparatively, if you watch the voltage over time. (discharge [voltage] slope in some vernaculars). When discharging back to nominal after final cycle and stopping the discharge at nominal you will typically see voltage rise again - or rebound - as the load is removed.
    Trying to get the car to use the traction packs strongest - longest lasting voltage range - or flattest area of the discharge slope - is not self evident for anyone reconditioning.
    The best way to know for sure is to have the voltage range data that the car used when new, than try to mimic that range as the pack ages and reconditioning lifts that voltage range higher. The trouble is that we don't have that voltage range to mimic, so we all kinda wing it the best we can using the data we have available.
     
    #6 vvillovv, Oct 26, 2020
    Last edited: Oct 26, 2020
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  7. jerrydelrey

    jerrydelrey Member

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    I see, so after the final cycle the end voltage is really high. Since I wait a few hours, the voltage actually drops a little. So I probably was not venting the batteries when drove the car the next morning.

    Yes it would be nice to know the set cycle discharge/charge voltage. I was just randomly going to discharge down to 225-230V.

    You gave me an idea. I'll monitor my car, and see when it generally starts charging. The Max V, i read when charging is 236V. I'll just discharge to the average of those 2 values.
     
    #7 jerrydelrey, Oct 26, 2020
    Last edited: Oct 26, 2020
  8. ASRDogman

    ASRDogman Senior Member

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    Anyone know of anyone who installed a voltmeter on the hybrid battery and put it on
    the dash to see the voltages?
    I know there are apps that can monitor it, but it seems it would be better to have a meter
    connected directly to the battery. Maybe a relay that connects only when the car is on?
    And maybe a push button switch to see it when the car is off?
     
    #8 ASRDogman, Oct 26, 2020
  9. jerrydelrey

    jerrydelrey Member

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    I haven't installed a voltmeter. But your right, i'll be easy to install.

    If i can get harness like the prolong's kits, then i'll up on right away. If anything I'll install an old voltmeter from my G-1 Insight the next time i go in to my pack. Hopefully a long time from now. hah
     
    #9 jerrydelrey, Oct 26, 2020
  10. ASRDogman

    ASRDogman Senior Member

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    Well, you can buy a meter for the dash, or "a" dash volt meter, like they had on older cars.
    Of course it needs to be a 300 volt meter.
     
    #10 ASRDogman, Oct 26, 2020
  11. jerrydelrey

    jerrydelrey Member

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    I just did a recondition. I did not disconnect the 12V. The starting voltage was 227V.

    After the 3rd discharge/charge cycle, I waited for 1 hour, then I discharged down to 230V. 8 hour later Car drove to work. I was normal not running to charge the battery.

    Previously I disconnected the 12V. This is probably why it drove normal. I discharged to a round number above the starting voltage.

    In my minds eye, my battery were not venting. ;)So I think I will keep doing it this way.(y)
     
    #11 jerrydelrey, Nov 4, 2020
  12. Ed Beaty

    Ed Beaty Active Member

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    12V connected or disconnected has NO bearing on the Prolong system (this is apparent from reading the user instructions). I leave mine connected during the Prolong recondition so I can leave my tailgate open without discharging the 12V. After all is done, tho, I do disconnect the 12V for a couple minutes to reset the Prius system's awareness of the new HV level. (also apparent from from reading the user instructions...).
     
    #12 Ed Beaty, Nov 4, 2020
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