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  1. #1
    RC Racer
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    TRX Lipo 6700 2S, manual storage charge and voltage?

    I'm using an Onyx 245 charger with my new Traxxas Lipo batteries. I'm not planning to run the truck for a week, so I plugged them in to the charger and balance boards and charged them to 7.7v or 3.85 per cell. I turned the charge cycle off and observed the batteries begin to drop voltage. They were creeping down. I unplugged them and plan to plug them in tomorrow to check the voltage level after resting over night.

    Is it normal to see the voltage drop immediately after cutting the charge cycle at 3.85 volts per cell?

    I'm really thinking about just dumping all of my chargers and going with a higher dollar charger like that 4X I've been drooling over at the local hobby shop!

    This is my current mess, I have many ni-mh and only the 2 Lipo batteries currently, but I think I'll transition over to the Traxxas 6700 mah 2S packs for my E-Maxx and summit. The run time is exceptional!



    Sent from a Galaxy S3, far....far away.

  2. #2
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    The reason it's dropping is because the charger is at full current when you stop the cycle, LiPo chargers reduce the current near the end of the cycle to stabilize the voltage so if you don't run a full cycle you're missing that part. I noticed the same thing with my older Ice charger, resting voltage would be between 3.4-3.7 if I stopped the cycle at 3.85v. Both my Hyperion and Traxxas chargers have storage settings and it really makes things much easier.
    Revo.27TX/Jato.18/Maxx523/Maxx3.3/GMAXX/Rusty/ERBE

  3. #3
    RC Racer
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    So, for me to store, should I overshoot the 3.85 to say, 4.1 knowing that when I unplug that I'll likely see them drop back into my 3.85 volt area? I need to get out of bed and go see how far they dropped overnight before they leveled out. I'll report back with that.

    Sent from a Galaxy S3, far....far away.

  4. #4
    RC Racer
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    Ok, I went down and stuck the Traxxas batteries on the charger (not turning the charger to charge mode) just to see what happens to my voltage that I stopped at 7.7 volts (I balance every charge, so it was 3.85 volts each cell).



    So, after setting all night, i lost just around .2 volts from each 2S pack. Would this put me in a safe storage voltage? Or maybe being that I lost .1V, I should push up to 3.95 volts per cell or 7.9 volts per 2S pack and see if it falls back to the recommended 3.85 volts for long term storage.

    Sent from a Galaxy S3, far....far away.
    Last edited by larry0071; 01-27-2013 at 08:49 AM.

  5. #5
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    I know when I pull my packs off my charger they do not drop in voltage.
    I have had a set in storage for the past 8 months or so... still 3.85v/cell.

    Please make sure the x4 you are thinking of getting is name brand... a member here has personally witnessed knock off chargers burn down garages filled with thousands of dollars worth of RC equipment.

    Also, nothing against the HiTec X4, but all it really is is 4 50 watt 5 amp chargers in one case.
    Whatever it is I just said... I could be wrong.

  6. #6
    RC Racer
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    Jimmie, I've changed gears. I'm thinking the version that has capability of 10 amps per channel and does the storage charge. I'll also need a power supply rated at 400 watts.

    Sent from a Galaxy S3, far....far away.


    Anytime you see ** in place of words you wrote, edit them out.
    Last edited by Double G; 01-27-2013 at 03:18 PM.

  7. #7
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    Asterisks (*) mean you tripped the word filter... I suggest editing them out before they are seen by a moderator.

    Sending you a PM.
    Whatever it is I just said... I could be wrong.

  8. #8
    RC Racer
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    I spent the day playing around with my batteries, charged them all with the same charger and left them to rest for a bit and then checked voltage on each ni-mh pack. Based on the total voltage, I believe that I have two blue battery packs that have a dead cell, do we all agree?



    Sent from a Galaxy S3, far....far away.

  9. #9
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    Possible.
    Does any one cell feel hotter during running or charging?

    That is another way to tell.
    Whatever it is I just said... I could be wrong.

  10. #10
    RC Racer
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    I've not noticed one cell that stands out as hotter than the general pack,


    Sent from a Galaxy S3, far....far away.
    Last edited by Double G; 01-27-2013 at 08:02 PM. Reason: content

  11. #11
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    If you toss them, discharge them completely and cut off the connectors. Those are reusable.
    Whatever it is I just said... I could be wrong.

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