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USA Low battery warning

Discussion in 'Certified UAV Pilots' started by howard a griffin jr, Jan 10, 2016.

  1. howard a griffin jr

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    Mr. Editor. Please feel free to remove this post if it is a repeat, but I feel the need to share this with fellow I1 pilots. Specially those that are new to I1 commercial ops.

    I was playing around with my I1 indoors. Had the Low Battery warning set for 20%. On this particular flight I was testing weight and balance for a light installation on my I1. I was well within the low battery warning with no concern because the aircraft was right in front of me. What I experienced was the control lever inputs change due to varying current to the engines. I landed with only prop damage, but lesson learned. Can't wait for comments on this one.

    Now with the previous incident in mind, I was checking for camera vibration for a prop adjustments. I would start the motors, increase power, but never come to a hover. I got the appropriate low battery warning, but ran the I1 past the low battery warning only for a few minutes. Lucky I was on the ground because the battery went from 20% to 3% and the engines shutdown. Thank the heavens I wasn't flying.

    I pass this on because we want to maximize our flight time for the sake of getting that video or picture. The lesson for me is to monitor the battery level while in flight, check the winds for the return leg and most importantly, when I hear that low battery warning, make a beeline home.
     
  2. IrishSights

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    My policy is that I'm on the ground at 30% or more...always
     
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  3. IrishSights

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    Also flying with less than 20% will shorten your battery life, your aircraft life, your insurance excess life and the life of what your flying over. If I were you I'd be researching lipo care, even on this forum. Loads of previous good threads on the subject.
     
    #3 IrishSights, Jan 10, 2016
    Last edited: Jan 11, 2016
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  4. The Editor

    The Editor Moderator
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    Hi Howard,
    Are you running v1.6 of the FW?
    When did you last calibrate your batteries?
    As a commercial operator I make it a point never to have props on my aircraft indoors however, that aside I would always advocate going into the battery info screen at least three times every flight (I actually have a shortcut into that screen assigned to C2 on the remote so I have instant access to it). It's a good discipline to get into.
    Also, other than to calibrate my packs I have never been airborne with under 20% left in the battery and have usually landed by around 25-28%.
    I would always rather come back in and land and swap batteries than try and squeeze an extra minute or even few seconds out of a pack.
    Glad you were not 'seriously' flying at the time!
    Let me know about the firmware versions etc and your last battery calibration on those packs.
     
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  5. ringolong

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    What do you guys do about voltage drop? My battery was at 58%, but the voltage would drop below 3.5, 3.46 to be exact under full forward so I slowly cruised back where is was 3.68. I brought it on down and it was at 42% when I landed. (Was a little ways out) This was on the smaller TB47 battery.

    I dont fly with it much, but I don't think I have noticed this on my TB48 batteries.

    I land when anyone of my cells hit 3.72 on my larger ac.
     
  6. The Editor

    The Editor Moderator
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    You are fine at those sort of levels - the important thing is what the voltage recovers to once the load is removed.
    Flying down to 3.45v or even 3.4v per cell under load is usual as long as the pack recovers after rest to around 3.7v per cell.
    This would mean you are taking almost exactly 80% out of the pack which is absolutely fine.
    You can confirm this by looking at how much is left in the pack when the resting voltage has returned to 3.7v. It should be around 1140mah for a TB48 and 940mah for the 47's.
    Just always be mindful that at colder temps the voltage dip maybe more under load and an aging pack will have an increased internal resistance and therefore not give up its charge so readily as a newer pack.
     
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  7. howard a griffin jr

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    Roger. Understood......
     
  8. howard a griffin jr

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    I am running FW V1.6 and batteries updated. Other than checking battery info, I haven't had my batteries calibrated. Point taken about running props indoors. I plan on making it standard practice to be home bound at 30%.
     
  9. howard a griffin jr

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    Point taken......
     
  10. howard a griffin jr

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    I went back and found the 50% batt life to 3% instantly experiment thread and found one of you posts referencing the battery does and don't.