Welcome to InspirePilots.com

Join the leading DJI Inspire community for free!

life of the battery

Discussion in 'Inspire 1 Discussion' started by gurke, Dec 9, 2015.

  1. gurke

    Joined:
    Dec 9, 2015
    Messages:
    4
    Likes Received:
    0
    hi,

    i'm thinking of buying a used inspire. The guy told me he has two batteries which have 85% lifetime and ~40 charges

    How you definde "lifetime" ?

    Does it man if you have 85% lifetime the capacity is moreless 85% left?
    Or do you also have enough capacity <80% at 10% lifetime and this value just calculate a date until you better throw the battery away?

    Anyone knows how this works? And at what % of lifetime you wouldn't use the battery then?

    many thanks
     
  2. Scotflieger

    Joined:
    Mar 29, 2015
    Messages:
    1,244
    Likes Received:
    576
    Location:
    Buckie, Scotland, UK
    Hi, welcome to the forum. The DJI TB47/TB48 batteries tend to consume 1% of the remaining life every 4-5 charges (based on my detailed battery records). For the 85% life remaining I would would expect the battery to have been charged at least 60-75 times. The charges you have been quoted don't look right to me. Ask for a screenshot of the battery page and how many times it has been calibrated and deep cycled.

    The maximum overall capacity (mAh) will also drop as the battery ages. The decision to buy is obviously yours but I would be cautious.
     
  3. gurke

    Joined:
    Dec 9, 2015
    Messages:
    4
    Likes Received:
    0
    ok thx, i will. I heared that it also depends how much capacity you let in the battery at least. So if you fly every time to 5% the battery looses lifetime much easier.

    The question is until what % you can fly it without risk and not flying just 2 min.

    Does DJI reccomend anything? I don't find anything.
     
  4. Scotflieger

    Joined:
    Mar 29, 2015
    Messages:
    1,244
    Likes Received:
    576
    Location:
    Buckie, Scotland, UK
    I never land beyond 20% which might account for the difference in values quoted.
     
  5. gurke

    Joined:
    Dec 9, 2015
    Messages:
    4
    Likes Received:
    0
    yes, that's what i mean.

    The question is what % of "lifetime" you can still fly without any risk and a "good" flyingtime. I can't beleave nobody asked this yet. I send dji an e-mail, but I didn't get any resond :(
     
  6. The Editor

    The Editor Moderator
    Staff Member

    Joined:
    Aug 7, 2013
    Messages:
    6,716
    Likes Received:
    3,871
    There will not be any risk, you will get fed up with short flight times long before the battery gets to 0%
    In reality, you will retire the pack when you feel it is just not giving you decent service.
    Some people will look after their batteries much better than others. Some will not even think they are abusing their packs, some won't care.
    The ONLY way to know how a battery has been cared for is to purchase it from new so you know its entire history.
     
  7. gurke

    Joined:
    Dec 9, 2015
    Messages:
    4
    Likes Received:
    0
    Of course would be "new" better.

    So you say the lifetime also says how long you can fly with this battery?

    So if the lifetime drops to 70% the battery gives you also only 70% of capacity and flying time?

    At an other post i read that you can use the full 100% lifetime normally and that the capacity is also ok at <20%lifetime.


    Hmmm strange that DJI doesnt write anything to this in there manual.