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Thread: help!

  1. #1
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    help!

    My lipo charger died on me. My lipos are at 3.87 per cell. Will my lipos be ruined if i dont get them charged soon? I know you can run them dead and not charge them, but im not sure about half dead.

  2. #2
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    LiPo's have no memory. You can charge and discharge from any charge state as long as you stay between the low and high voltage limits.

    3.87v is close enough to storage voltage not to worry about them for quite a while.
    Whatever it is I just said... I could be wrong.

  3. #3
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    Nice. Thanks.

  4. #4
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    Quote Originally Posted by ahtwl08 View Post
    My lipo charger died on me. My lipos are at 3.87 per cell. Will my lipos be ruined if i dont get them charged soon? I know you can run them dead and not charge them, but im not sure about half dead.
    You can't run lipo's till they're dead and store them . they have to be at storage level to store them .
    1 Rusty VXL

  5. #5
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    Good catch... I definitely missed that the first time I read it!!

    It is very dangerous to not charge a LiPo after use... they should be brought up to storage voltage shortly after a run in order to keep them from over-discharging to unsafe levels.
    Whatever it is I just said... I could be wrong.

  6. #6
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    sorry, that was a typo. should've said I know you CANT run them dead without charging. I just never was sure about them being half dead. I got them charged thankfully. they were brand new batteries. bad thing is, the charger was too.

  7. #7
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    What charger?

    You are not supposed to store them charged either.

    Here is the storage excerpt from my LiPo 101 post:
    Storage
    Storage voltage is 3.85v/cell. This voltage is the only voltage that is not super critical for LiPo. Anywhere between 3.5-4v/cell is considered to be acceptable for short term storage. If the pack is going to be stored for more than a few days, bring the pack closer to 3.85v/cell. I suggest putting a full pack to storage voltage if it is not going to be used within 30 hours or so. The longer a pack is at full capacity, the shorter its lifespan will be. I also suggest bringing a pack up to storage voltage shortly after a run. When a LiPo's voltage lowers to a certain point, they begin to loose their voltage quickly. I would hate to see you loose a pack (or more) due to not charging up within a few hours after a run.

    For long term storage; I bring my packs to storage voltage, seal them in an airtight container, and stick them in the refrigerator. I have had a set of 3S packs in the fridge for over 8 months at storage voltage before... I checked them monthly and they never strayed far from 3.85v/cell. When storing packs for extended periods, it is a good practice to take them out every 4-6 weeks to cycle them... bring them down to LVC and then charge them back up to storage voltage. This will keep the chemistry active and ready for use when you are ready.
    Whatever it is I just said... I could be wrong.

  8. #8
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    How can I tell when to stop running my slash. I have a traxxas 3 cell 11.1 volt 25c 5000mah battery. The stock esc has a cutoff that's lower than 3.8 from what I understand so wont that damage the lipo. I think the esc cut off is 2. something, can't remember. Is that safe enough from that voltage to bring back up to 3.8 volts to store it. Is it safe to recharge the lipo to full capacity from the esc's cut off voltage to use it again. What does the esc do when it reaches the cut off voltage does it beep to let you know to shut off the esc and unplug the battery or shut itself off when reaching cut off voltage.

  9. #9
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    3.8v/cell is storage voltage... you can discharge it lower than that without hurting anything.

    Safe low voltage is 3.4-3.5v/cell.

    None of Traxxas ESC's trigger low voltage lower than that.

    Yes, it is safe to charge and reuse. Just make sure the packs are cool to the touch when the charge cycle starts.

    Stage 1 LVC = 50% power
    Stage 2 LVC = no power to the motor
    No beeping

    Always unplug the battery when it is no longer powering the RC.
    Last edited by Jimmie Neutron; 03-29-2014 at 04:27 PM.
    Whatever it is I just said... I could be wrong.

  10. #10
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    Ok thank you, much appreciated. I had these questions in the slash 4x4 area then realized their was the lipo section, sorry for posting in the wrong area

  11. #11
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    Either area will work... just not both.
    Whatever it is I just said... I could be wrong.

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