Welcome to PhantomPilots.com

Sign up for a weekly email of the latest drone news & information

How bad is it really to store battery at 100%?

Discussion in 'Pro/Adv Discussion' started by Saudio, Apr 5, 2016.

  1. Saudio

    Joined:
    Jan 8, 2016
    Messages:
    28
    Likes Received:
    15
    I've been trying to follow the guidelines for battery storage, I run my batteries down to 50% before long term storage and I have my batteries set to discharge after 48 hours. But I really like the ability to fly spontaneously, whenever I feel like flying, on short notice. I like to video wildlife, and if there are geese on the pond and I have 50% batteries, forget about it. I actually grabbed a 50% battery one time for a quick flight to fly with buzzards, and I ended up with critical low voltage and RTH. It was not fun.

    I curious if there is any good data on just how quickly storing at 100% damages a battery. I'm thinking about having one "sacrificial" battery that I keep at 100% all the time, but I'm wondering how quickly that will ruin it.

    Any thoughts?
     
    MC_ likes this.
  2. dysan911

    Joined:
    Mar 12, 2015
    Messages:
    298
    Likes Received:
    60
    I don't know if it's related but typically I try to only charge mine the day before I use them. After that I store them with whatever charge remains. I do have two batteries and charged both the night before a flight I was planning to use both batteries the following day. Well I only used one of them so the 2nd battery remained 100% full and was stored like that. About a week went by and I used that same battery to update my firmware and got the message I had a bad cell. Long story short that battery is now useless and DJI only warranties the batteries for 6mos so I'll have to buy another 6mo warrantied DJI Battery.

    That battery above only had 8 charge cycles on it. :( I won't be leaving mine stored fully charged. Also I believe we can change the # of days before it will auto discharge in the DJI Go App. Mine was set to default.
     
    MC_ likes this.
  3. 4wd

    4wd

    Joined:
    Mar 31, 2014
    Messages:
    2,532
    Likes Received:
    421
    Location:
    North York Moors
    There were a lot of problems with Phantom 2 batteries which used similar technology but didn't have auto discharge.
    Or rather there were considerably more problems than are being reported with P3s.
    It only takes about 30 minutes to charge from 50% - not too difficult but agree a bit annoying.
    Buying a second charger and/or car charger is helpful.
     
    MC_ likes this.
  4. Saudio

    Joined:
    Jan 8, 2016
    Messages:
    28
    Likes Received:
    15
    Yeh, 30 minutes is not that long, but lots of stuff comes and goes in 30 minutes. Missed the peak moments of a great sunset a couple nights ago, for example.
     
    MC_ likes this.
  5. Meta4

    Meta4 Moderator
    Staff Member

    Joined:
    Jan 8, 2014
    Messages:
    7,763
    Likes Received:
    3,470
    There's a reason DJI made the P3 batteries self discharging - it's because storing at 100% will ruin them.
    You mentioned flying with a battery that's been sitting at 50% - that's also a good way to lose your Phantom when it falls from the sky.
     
    snowghost and MC_ like this.
  6. Saudio

    Joined:
    Jan 8, 2016
    Messages:
    28
    Likes Received:
    15
    I understand that it will ruin them. My questions is if there is any data about how fast that will happen. Do you get 75% of the normal recharge cycles by storing at full charge, or do you get 25% of the recharge cycles?

    Just determining roughly how expensive it is to sacrifice a battery in order to be able to fly on short notice, which is important to me.
     
    MC_ likes this.
  7. BigAl07

    BigAl07 Moderator
    Staff Member

    Joined:
    Jan 5, 2015
    Messages:
    2,362
    Likes Received:
    1,267
    Location:
    Western North Carolina
    With all due respect you know when the sun sets you can be more proactive on your battery duties than this.

    At 100% capacity the battery will start "Degrading" within the first 24hrs. The amount is very minute but any time the battery is stored at full charge it "can" harm the battery. The cooler the environment the less harm done because this whole process is a chemical reaction. On a side note before the "Smart Batteries" we kept our batteries in a cool area for storage. There were times when I had over a dozen LiPo batteries in the "Vegetable Bin" in our refrigerator for months at a time. I've got batteries with over 150 charges on them and they are still "operational" although not nearly the PUNCH of a new battery. Battery "punch" isn't nearly as important for fixed wing aircraft as it is for helicopters and multirotors.

    I have my aircraft "Mission Ready" 24/7 by always having a single battery at 100%. In order to maintain this I have to have detailed battery logs and rotate my batteries carefully so the same one isn't always the "Mission Ready" battery. I have Auto-Discharge set to 3 days and whichever battery is "Mission Ready" is "Checked" before the 3-day period is up. But.. and I stress but, I only allow that one battery to stay 100% for a WEEK max. When I hit the 7 day mark (I picked 7 days randomly) I either make sure I fly or I will use that battery for FW updates etc. and allocate the next battery in sequence to be my mission ready battery. To date this has only come into play 2 times since last summer.

    Also I utilize the "Blue 3 battery charger" so only having a single battery Mission Ready is not a show stopper. I can get the 3 remaining batteries topped up and ready to go in less than an hour from a "Storage Charge State".
     
    Hemar174, NRJ, snowghost and 4 others like this.
  8. Mark The Droner

    Joined:
    Aug 26, 2015
    Messages:
    4,026
    Likes Received:
    1,177
    Location:
    Brookeville, MD, USA
    This is your hobby. If you want to keep a battery at full charge in order to see the geese in the pond, then you should do it. Obviously, you know the batteries will self discharge. I do like BigAl's advice on rotating batteries.
     
    MC_ and WetDog like this.
  9. Saudio

    Joined:
    Jan 8, 2016
    Messages:
    28
    Likes Received:
    15
    Thanks for that response, maybe rotating batteries is a better idea than keeping the same one charged. And also, with all due respect, there is a sunset every night but the ones that are worth capturing with video are infrequent and unpredictable. ;-)
     
    Hemar174, MrTommy, snowghost and 2 others like this.
  10. BigAl07

    BigAl07 Moderator
    Staff Member

    Joined:
    Jan 5, 2015
    Messages:
    2,362
    Likes Received:
    1,267
    Location:
    Western North Carolina
    Very true.
     
  11. richwoodrocket

    Joined:
    Mar 21, 2016
    Messages:
    64
    Likes Received:
    10
    In the app it allows you to set it to discharge to 65 percent after 10 days. I can't imagine that they would give you that option if it was going to cause problems or drastically shorten the life of the battery.
     
  12. ianwood

    ianwood Taco Wrangler
    Staff Member

    Joined:
    Jan 7, 2014
    Messages:
    4,930
    Likes Received:
    1,801
    Location:
    Lost Angeles
    You don't know DJI!
     
  13. WetDog

    Joined:
    Oct 18, 2015
    Messages:
    1,491
    Likes Received:
    640
    I keep one battery on 'hot charge'. I rotate that battery although I'm not compulsive enough to log which one has gone through that.

    Yes, I might miss out on some battery life but that is less important than missing out on a picture. YMMV.
     
    MC_, Mark The Droner and BigAl07 like this.
  14. shockwave199

    Joined:
    Dec 19, 2014
    Messages:
    1,067
    Likes Received:
    405
    I find this frustrating as well. I have been in tight situations literally pacing while waiting for a battery to finish charging. I never had a problem charging my yuneec batteries to 80%- a quick pump up- for a last minute short flight in a hurry. I just do not trust doing that with P3 batteries. It's full or nothing and that really puts a hurt on last minute, must do flights. Not everyone is a casual, fly when you feel like it operator. But I simply will not fly unless I have a full, fresh charge. I suppose you can charge a battery each day and if you don't fly it, fly it down to 50% each night. That's quite a routine though. You have to have a real need to do that on a consistent basis.
     
    MC_ likes this.
  15. m0j0

    Joined:
    Dec 26, 2015
    Messages:
    1,533
    Likes Received:
    530
    I charge my batteries and fly. If I miss flying the first day I don't worry too much but after that I'm looking to bring them down to 50%. I can't answer your question about how much the battery is damaged though
     
  16. Romans109

    Joined:
    Mar 14, 2016
    Messages:
    310
    Likes Received:
    43
    if you store your battery at a low percentage, there's a higher risk of it expanding and possibly malfunctioning. i always keep mine at 100% then if i fly i'll use it almost all the way up then charge it back to full, after all they are designed to discharge automatically but even still don't rely on that, keep em charged. that's my take


    Sent from my iPad using PhantomPilots mobile app
     
    Suzi spaniel likes this.
  17. Romans109

    Joined:
    Mar 14, 2016
    Messages:
    310
    Likes Received:
    43
    [​IMG]


    Sent from my iPad using PhantomPilots mobile app
     
    Suzi spaniel likes this.
  18. With The Birds

    Joined:
    Jan 4, 2016
    Messages:
    2,614
    Likes Received:
    745
    Location:
    Australia
    Some interesting numbers, taken from "battery university" of application to LiPo chemistry.

    One year storage at 25 degC...

    96% usable capacity if state of charge at 40%

    70% usable capacity if state of charge 100%

    Effectively you are loosing 1/4 of the battery deliverable mah with direct impact on flight time.

    These numbers seem good... i have seen lipos that were useless (hitting LVC cutoff in flight with) with less than 30 cycles where the owners diligently kept them at 100% and that was in a less than 4 month period.

    Edit- it seems current dji app now gives 1 day as an available auto discharge commencement setting.

    This is good, would be better if they could offer packs that could take a 3C charge. Sub 15 min ave wait time on the charger would be a nice compromise.
     
    #18 With The Birds, Apr 6, 2016
    Last edited: Apr 6, 2016
  19. Romans109

    Joined:
    Mar 14, 2016
    Messages:
    310
    Likes Received:
    43
    you did read the picture above yea?


    Sent from my iPhone using PhantomPilots mobile app
     
  20. With The Birds

    Joined:
    Jan 4, 2016
    Messages:
    2,614
    Likes Received:
    745
    Location:
    Australia
    No... i read your post above that said keep them at 100%. I have read it now.