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BL Limitation Error

Discussion in 'Electronics' started by Andrew Goodwin, Oct 15, 2012.

  1. Andrew Goodwin

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    Hey guys, just wondering if you guys know the various reasons for this to show up? I know Josh mentioned his comes up with it reaches really high temps in Arizona, but I've seen it two or three times now, always at the end of the flight when landing. I've never seen a BL go over 90 degrees, so it's definitely not temperature, ambient this time of year is nice and low.

    I'm doing a bunch of altitude lock flights tomorrow, so I don't want any weird issues as a result of this. Any help or thoughts would be greatly appreciated.
     
  2. Josh Lambeth

    Josh Lambeth Well-Known Member

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    I have also been getting them when it's cooler recently. I looked at my GPX file and it doesn't register there that I have any errors which I find strange. Also non of the max amps per BL is anything out of normal.

    Check all your CAPS on the bottom side of your BLs to see if they are loose and also check to make sure you don't have any wire hairs trying to get away from you and cross between the different solder points.

    Josh
     
  3. Howard Dapp

    Howard Dapp Active Member

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    Current limiting kicks in when amp draw reaches a set amount. You're seeing it at the end of your flights because your lipo voltage drops which in turn raises amp draw. Current limiting reduces power to the engine pulling amps over the set amount. If you guys were flying quads you would probably have controllability issues once current limiting kicks in. Not so noticeable in hexas and octos.

    Check your controllers like Josh suggested. If it's not a hardware issue, try raising your limits some.
     
  4. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Are you just seeing this in telemetry? I guess what I'm asking is how does the BL Limitation error show up?

    Andy.
     
  5. Josh Lambeth

    Josh Lambeth Well-Known Member

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    In my situation my MX20 will start beeping and will show "BL Limitation" down in the bottom of the screen but then when I look at the GPX file there is no error logged.

    Josh
     
  6. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Understood. Man, I hate to look down when I'm flying....so much can go wrong....

    Does the MX20 do the bi-bing-bi-bing tone? I've occasionally had that without any low voltage warning and been wondering what was going on....

    Andy.
     
  7. Josh Lambeth

    Josh Lambeth Well-Known Member

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    Yeah I'm not a huge fan either. I try to use the voice telemetry as much as possible.

    Josh
     
  8. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    I feel sooo exposed when the lady in the MX-20 is not calling out the input voltage every 15 seconds....so I fly like a tightrope walker -- I never look down! :)

    Andy.
     
  9. Andrew Goodwin

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    Yeah it's showing up in Telemetry on laptop (through Xbees). I must admit I'm spoiled. Our flight permits with Transport Canada require that we have a three person crew (when using dual operator setup with 360 mount). I have the third guy or gal next to me with the laptop constantly reporting altitude, lipo voltage, gps position from the map (so I don't go too close to things Transport Canada doesn't like us going close to, like peoples homes)...etc. And he reports when we're getting any error messages too. I never have to look down!

    So yesterday I was flying with altitude lock on, and man it was testy. I was getting all kinds of over-amp warnings (not a BL limitation mind you, just the amp-meter on telemetry laptop kept going red).

    No BL limitation errors yesterday.
     
  10. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Aha! That's Transport Canada's Full Employment approach, isn't it. (Sorry, used to live in Toronto ("Trana") some years back.)
    What kind of current draw were you getting (total) when you were on altitude hold?

    Andy.
     
  11. Josh Lambeth

    Josh Lambeth Well-Known Member

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    What camera were you flying?
     
  12. Andrew Goodwin

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