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  1. #1
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    Making LiPo's last

    I electronic guru friend of mine has a pretty sweet set up for testing LiPo's...
    He does a lot of independent LiPo testing for companies that want to put truth and not hype on their packs.

    He just finished a 1000 charge/discharge cycle test on two identical packs. The only variable was that one pack was always charged to 4.2v/cell and the other was always charged to 4.1v/cell. I will let the following graph speak for itself:

    Whatever it is I just said... I could be wrong.

  2. #2
    RC Turnbuckle Jr. Carbonrevo33's Avatar
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    Wow, very sensitive battery technology! I assume it goes for all batteries, some more than others, but still!

  3. #3
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    I have always charged (unless for speed runs) my packs to 4.17v/cell. When asked why my answer has been "so they last longer"... I was mostly scoffed at and told there would be no difference... I am glad that now there is proof!
    Whatever it is I just said... I could be wrong.

  4. #4
    RC Turnbuckle Jr. Carbonrevo33's Avatar
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    In THEIR face right? I'll definitely change my battery care methods now, even though my batteries are cheaper than most, I don't want to buy replacements more often than I need to.

  5. #5
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    You would only loose a few minutes of run time and get over double the usable cycles out of the pack... well worth the sacrifice.

    I realize that packs are super cheap... or can be super cheap, but the less money I have to spend on maintenance, the more money I can put toward improvements and even a new/different RC.
    Whatever it is I just said... I could be wrong.

  6. #6
    RC Turnbuckle Jr. Carbonrevo33's Avatar
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    Ok cool. Too bad I can't adjust the voltage rate going into the packs, or am I overlooking a simple fact? I'm using an Onyx 230. And ain't that the truth!

  7. #7
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    But Jimmy, I'll lose .3v of power for the first 2-3 minutes of my usage!!!

    Am I reading that correct, he is dropping down to 2.5v per cell before recharging?

    Thanks for the data, I'll be changing my end voltage tonight

    "RED"

  8. #8
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    The termination voltage may only be adjustable on higher end chargers... one more reason to get one over a cheaper charger.

    LiPo "absolute 0" is 2.5v/cell.
    3v/cell is typically used as a low for real world usage due to how fast voltage drops toward the end of depletion. In RC, stopping too much closer to 2.5v than 3v could result in catastrophic failure. This knowledge is part of the reason why I do not hesitate to use 3.1v/cell as a LVC... I stop at first sign of LVC and bring the voltage back up to at least 3.85v within 15-30 minutes of running. Another reason 3.1v/cell is an OK LVC is voltage dip... when pulling amps LVC is going to kick in when actual resting pack voltage is higher. But, caution is needed in a low draw system... for instance; a 10th scale Summit in low gear. Amp draw is low enough that a 3.1v/cell LVC setting could easily over discharge a pack as there is very little voltage dip due to less amperage being drawn out of the pack.

    Hope this all makes sense!

    Also, keep in mind that he is discharging packs in a very controlled environment... a computer is monitoring and recording everything that is happening to these packs. Do I agree with testing to such a low voltage? not really, but I am sure if I asked there would be a very good reason.
    Last edited by Jimmie Neutron; 10-02-2012 at 12:20 PM.
    Whatever it is I just said... I could be wrong.

  9. #9
    RC Turnbuckle Jr. Carbonrevo33's Avatar
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    Quite confusing, but it makes sense. Wish I had invested in a different, more featured charger, but when I got the Onyx years ago, it fit my needs at the time.

  10. #10
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    I just noticed my first post says "I" instead of "An" electronic guru.
    lol

    And I probably should have put "absolute zero" instead of "0" in an attempt to keep it easier to understand.
    Whatever it is I just said... I could be wrong.

  11. #11
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    The wholesale / dealer of SPC racing told me to set my LVC at 3.5 on my Erbe and spartan because of the high draw the castle system pulls. Guess I'm on the high end of the safe side. Good info. An awesome charger is hitec x4. Can charge, balance, store and quick charge 4 lipo's, nihm's or any other all at the same time. Awesome unit



    Beatings will continue until compliance is gained
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  12. #12
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    That HiTec is an "OK" charger...
    it is basically 4 50watt battery cookers in a single case.
    Whatever it is I just said... I could be wrong.

  13. #13
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    Quote Originally Posted by Jimmie Neutron View Post
    That HiTec is an "OK" charger...
    it is basically 4 50watt battery cookers in a single case.
    What do you mean " battery cooker" ?
    It seems to work great for the few months I had it


    Beatings will continue until compliance is gained
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  14. #14
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    The way chargers charge is different from a cheaper charger to a more expensive charger.
    But since this thread is NOT about which charger is better or how chargers work, I am going to leave it at that.
    Whatever it is I just said... I could be wrong.

  15. #15
    RC Turnbuckle Jr. DiggerPede's Avatar
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    Jimmie good info as always. Better late then never ( for me ). I'm going to drop mine down to 4.17v / cell when I charge. I'm not so worried a bout a few minutes of runtime.

    But on the flip flop maybe my philiosphy is different. If I get a 100 charges out of a pack i'm doing good. More the better!! It's just that everything gets better over time whether it be "c" rating or more mah. I dont know just my thoughts in general. LOL

    If you take a $50 Lipo and get a 100 charges off it, that would equal 0.50$ / run. I find that dirt cheap. If you get 500 charges, then it would be 0.10$. Even more 1,000, it would make it 0.05$ / run. I know that last number is better and could be achieved if you took perfect care of the pack.
    Weak Revenge
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  16. #16
    Marshal ksb51rl's Avatar
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    The FMA Direct PowerLab chargers allow you to set the maximum voltage incrementally. Actually, they allow you to set almost everything incrementally. See below:



    The even have a preset named "LiPo|Generic Long Life (4.1v)"
    Do you think they know what they're doing?

    I formerly thought the FMA guys were 1.) arrogant to the point of snobbishness; and 2.) that their way of doing things was unnecessarily complex and meticulous. Since owning one of their products, I no longer believe the latter point is true.
    Alt-248 on the number pad =

  17. #17
    RC Turnbuckle Jr. harry697's Avatar
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    Interesting thread. I'm curious to see the results using some different variables though. Most concern with lipos seems to be over discharging. So similar testing, but changing the cutoff point (say 3.5 vs. 3.0 vs. 2.5) while using the same peak voltage (whether it be 4.1 or 4.2 or whatever) would also be interesting as to overall battery longevity.

  18. #18
    RC Turnbuckle Jr. DiggerPede's Avatar
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    @ KSB you are right on there man!!! Those are the very reasons I love that charger. Them Guru's definitely know what they are doing. Plus creating your own profile of how you want it to work is just out of this world. I'm amazed in AWE with the graph. Kinda like a kid in a candy store. LOL
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