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I may have just screwed up.

Discussion in 'Gen 2 Prius Main Forum' started by SDunahugh, Jul 9, 2016.

  1. SDunahugh

    SDunahugh Junior Member

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    OK i just bought the hybrid automotive battery charger /dis-charger. I balanced the battery no problems.

    started the 1st discharge cycle again no problems, changed the bulbs from 200w to 75w at 167v (slightly under what they say to but that shouldn't be a problem?)

    was checking the voltage every so often but still over shot the 134v 1st stop point. It went down to 90v. (recharging it ATM)

    do I need to start over? IE take it down to 134v charge then 84v ect, or am I ok just charging then going to 84v on the next discharge cycle?
     
  2. WilDavis

    WilDavis Senior Member

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    …if you read the destructions, I think you'll find that it's OK to do what you did! …just take care that the battery isn't discharged at a high rate when almost discharged, so that the cells become reversed polarised (A Very Bad Thing!). An intelligent discharger might be a good investment if you're really worried about it happening again! (…but at $660, perhaps not!) - hope this helps - Wil
     
  3. SDunahugh

    SDunahugh Junior Member

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    i have read the instructions and i wasn't worried about that (I only over shot by 40v) the question was should I go ahead and start over, or just continue on following the instructions?
     
  4. JC91006

    JC91006 Senior Member

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    the 75w bulbs down to 90v might be a problem...I think you should be using low current 25w bulbs under 140v

    whatever you did, there's no turning back. No need to start all over, just continue as usual.
     
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  5. SDunahugh

    SDunahugh Junior Member

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    kinda sucks but that's what I though. charger on it now and will go ahead and re-balence, then start over (glad I own 2 prius'es) thanks for the Input
     
  6. JC91006

    JC91006 Senior Member

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    no need to start over, just continue.

    The reason you discharge is to recover lost capacity. You don't have to discharge again if you are showing improvement with your data. The reason Toyota limits the car to 40% discharge and 80% charge, is to maximize the number of cycles on the battery......to 10s of thousands of them. If you were to go below 40% and 80%, it would greatly reduce the life of the battery pack....but you'll have a stronger battery for short term.

    If your data shows your battery to be perfectly balanced after 2 cycles, you don't need to do the 3rd
     
  7. SDunahugh

    SDunahugh Junior Member

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    so charge to 235 (that's where it "stopped" went up to 237 during balancing) put the 25w bulbs in then goto bed and deal with bulb changes in the morning?
    so charge to 235 (that's where it "stopped" went up to 237 during balancing) put the 25w bulbs in then goto bed and deal with bulb changes in the morning?
     
  8. JC91006

    JC91006 Senior Member

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    I wouldn't go to bed while discharging. That's the thing about discharging, you have to watch it. The intelligent discharger allows you to set it and leave it....but that's $600

    Charge to 235 and wait until morning when you can discharge. Start with 100w bulbs to 200v, then switch to 60w to 140v, then 25w going lower. Using 25w protects the battery from reverse charging because of the lower current.

    When I discharge, I switch to 25w under 175v, just to protect it a little more....takes more time but it's safer from reverse charging

    Remember at 200v, the battery is already nearing empty. 7.2v x 28 = 201.6v
     
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  9. SDunahugh

    SDunahugh Junior Member

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    ok wont do that then, I was going off what they say on their website (25w bulbs take 4days to dis-charge) and in that case I may as well just leave the charger on over night and re-balance no?
     
  10. JC91006

    JC91006 Senior Member

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    you'd be surprise how fast the 25w bulbs take on a weak battery, 6 hours and it's down to 50v

    every battery pack is different, the stronger the pack, the longer it'll take to discharge. If your pack is weak, it can discharge at an alarming rate......and that knee bend area, it's like a freefall in voltage
     
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  11. SDunahugh

    SDunahugh Junior Member

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    thanks again for the help, will leave the charger on overnight (i wake up at 5am weather i want to or not) then start the 2nd dis-charge in the morning (watching it closer this time).

    Again thank you for the input
     
  12. JC91006

    JC91006 Senior Member

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    you really can't hurt it going down with the 25w, but it just takes longer
     
  13. fotomoto

    fotomoto Senior Member

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    You're fine. (y) The instructions state not to worry about dropping lower.

    What I've done is begin discharging when I'd get home around 5pm so I could monitor it (not continuously!) without too many distractions and begin the 12-18 hr charging process before heading off to bed. Rinse, lather, repeat the next day.

    The following is not a recommendation: I found the 25w can take too loooooong to fit the above schedule so I let the 75w go longer (deeper) and watch very closely.
     
  14. SDunahugh

    SDunahugh Junior Member

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    cycle #2 is going fine so far. not going to get the 3rd discharge done this weekend sadly. can I start and stop it next week? wont be home during the day to watch it so i was thinking discharge part way in the evening then stop when i need to go to bed /finish the next night
     
  15. JC91006

    JC91006 Senior Member

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    Don't discharge half way, a cell can reverse charge if left that way for a day

    2 cycles is fine, just drive it and you'll notice the improvement
     
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  16. SDunahugh

    SDunahugh Junior Member

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    thanks, will take it down to 17v then charge overnight on a side note I hit both bulb change right on the specked V this time (it drops FAST from 148v to 140v so anybody doing it for the 1st time stay on top of it in this range)