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Changing First & Second Level Protection

Discussion in 'General Discussion' started by MegaDeal, Jul 31, 2013.

  1. MegaDeal

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    I was wondering if any of you have lowered your first and second voltage protection to get longer flight time? What would be the lowest that can be recommended without causing damage to the battery?
     
  2. Ozzyguy

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    10.7 under load first warning.
     
  3. Gizmo3000

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    well, the first level protection is merely a warning,
    but 2nd level , loaded, is the one that you need to be most cautious about.

    Some guys are more daring and lower their 2nd level to 10.10 loaded, but I prefer to be a bit more conservative so that I don't drastically discharge my batteries.

    Here's my settings, which I find work fairly well.
    the goal is to have your cell levels near 3.72 or so when done, and to never have to put more than 80% back into a battery when charging.
     

    Attached Files:

  4. Ozzyguy

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    ^ my settings exactly:)
     
  5. Ozzyguy

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    This gets me around twelve mins flying time.
     
  6. ElGuano

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    The thing with voltage settings is that you really shouldn't just set and forget. If you change them, you really should be measuring after-flight voltage, and ideally confirming using an intelligent charger what you're putting back in on charge. And some people will have lower level 2 alarms because they're intend to never hit. Mine is set to 10.55 or 10.4 as well, but it's just there because I know I will never trip it in normal flight.
     
  7. Ozzyguy

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    ^yes you absolutely must do your own testing as per the voltage tab procedure in the NZa assistant. Don't just take our settings and hope for the best.
     
  8. MILLER4PRESIDENT2020

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    Can you elaborate on this procedure?
     
  9. Ozzyguy

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    It's all there on the voltage tab of the Naza assistant. Start with a full charged battery, fly till the first red voltage warning flashes and measure that voltage at the battery. Take 11.3 volts and minus your new voltage. In my case it was 10.7 giving a .60 difference. Enter what number you end up with in the middle box.
     
  10. MILLER4PRESIDENT2020

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    but what are you really testing here? The first set of red lights is a value you set. It comes on at the value you set. Not trying to sound like a dick, I understand lipo batteries are hyper sensitive but what is that test actually testing? Make believe I could set my first low voltage alarm to 10.3. Go do the described test and fly it around until the first low voltage alarm activates at 10.3. Take the difference 1 and set it in there. All that test did was prove that I set the value dangerously low?
     
  11. ElGuano

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    You're testing line loss, which is a confusing number. Assistant has you go through that procedure because, when you read the voltage of your Phantom's batteries within Assistant, you're not seeing what the NAZA sees under load. That 12.60v of a fully charged battery? Start the motors and it'll drop immediately to 12.00v--"under load." By having you go through this exercise, the NAZA is telling you that the voltage you see after a flight isn't the same number the low voltage alarm is reacting too.

    Some people just ignore the line loss, set it to zero, and set their no load values to 10.6 or 10.7v. As long as the final "Loaded" value shows up as that, it doesn't matter if you set no-load at 100.0 and line loss to 89.4.
     
  12. MILLER4PRESIDENT2020

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    Wow I'm confused now ha. Are there any more in depth articles on the internet so I can study more up on this?
     
  13. ElGuano

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    There are a lot of good threads on here and on rcgroups, but here's a good primer on RC lipos:

    http://www.rchelicopterfun.com/rc-lipo-batteries.html