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Self-Discharge Threshold - How long is too long?

Discussion in 'Inspire 1 Discussion' started by Fink, Dec 19, 2015.

  1. Fink

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    What do you guys have your self-discharge threshold set at? I have mine at 10 days now, but worry that's too long. Thinking of dropping it to five days or seven days.

    What do you currently have yours set to and why?

    Cheers.
     
  2. The Editor

    The Editor Moderator
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    2 days.
    My basis for that is I charge my batteries either on the day of flight(s) or the day before. If for whatever reason (weather, unforeseen circumstances, change of plans etc) I do not fly, the longest they will sit fully charged is one more day.
    If I then CAN make the flights it's a simple job to charge them or top them off by turning them on first if they are already at >95%.
    I do not want my packs sitting any longer than is necessary at full charge.
     
  3. John Alan

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    Have mine set at 2 days...
    Charge to 95+% (first shutoff) night before use... top to 100% (turn on then charge) morning of use...
    Remember it resets any time your push the button to check charge level... ;)
    If I find plans change and I need to hold it at 100%... start pushing buttons daily to keep them reset...
    It takes several days once the discharge starts (tops get slightly warm) to reach ~50%...
    I do be sure the batteries are NOT in my Go Pro case with the lid shut when discharge starts... o_O
    While I don't think much heat would build up inside a closed case at such a slow discharge rate..
    I'm not about to find out... :p
     
  4. Fink

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    Thanks for the response and feedback. Seems like I was right in wanting to reduce it, but now that I think about it and read your post (as well as John's), it does seem lowering it to around 2 days is best. Thanks again.

    Thanks very much for the response! Interesting on the 95% and then the 100% the day-of procedure. For some reason I have this innate fear of topping LiPos off. Not sure why. I'm doing it tonight for my flights tomorrow, though. I guess I just always want to keep the LiPo's juices moving so once it starts discharging, I prefer to keep it in that motion. I also worry that for whatever reason, once the self-discharge process begins, the voltages that the battery reads will be inaccurate for some reason so my mind likes the idea of just discharging them and then recharging.

    I surely wish DJI would incorporate a discharge and storage charge into their charging equipment or batteries themselves. Would be a huge improvement and allow us to maintain the batteries that much better.
     
    #4 Fink, Dec 19, 2015
    Last edited: Dec 19, 2015
  5. John Alan

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    I have given some thought of making a device to put between the Battery and Charger...
    Measure voltage and cut off charging at a value I chose for storage purposes...
    Example... plug in a battery I flew down to ~20%... stops charging at 50%...
    Not a need of mine... more like a want... o_O
    To discharge for resetting... I prefer to just fly it down...as I think that is more realistic...
    (12+ amp draw at hover, 25+ amps at speed)
     
  6. owenrg

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    Just got my inspire, so i'm wondering about how you guys set up your batteries. I bought it used so when the guy was flying it before i bought it, he got the critical voltage warning, but looks like i just needed to charge them all the way to reset them.

    Anyway, you mentioned topping them off. the charger stops at 95%? Are they like the P2 batteries where you plug them in, and turn the battery on and it'll top it off?

    Thanks.
     
  7. John Alan

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    Yes... with battery off... plug it in and it will come to life and charge itself up to around 95% or so...
    Unplug... turn battery on... plug back in... will top the charge up to 100%
     
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  8. Fink

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    Interesting. I was under the impression the batteries would fully charge before shutting off given that it's balancing each individual cell. I'll have to check and see what the voltages are this morning when I get out to the job site - I "fully" charged them all yesterday using the charging hub. Will be interesting to see where they are.
     
  9. Fink

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    Sounds like you just need to exercise the batteries a little. Check and see what the Inspire is reading as each battery's "health". It's under the battery menu and will be displayed in the lower-right pane. It's a percentage with 100% being brand new. It will also tell you how many times they've been charged, etc.

    The stopping at 95% is news to me - I had never really noticed. Either way, the process is the same as the Phantom's batteries. If the battery is below 75% charge, just plug it in and the charger will automatically start charging it. If it's above 75%, you will need to turn the battery on and then plug it in to the charger.

    I highly recommend getting the 180W charging cable and the Inspire Battery Charging Hub. It won't charge them all simultaneously, but it manages the charge of four batteries in series and saves you from having to babysit the LEDs and watch for a full charge to move on to the next battery. You obviously still need to keep an eye on the process, monitoring temps and watching for any errors, etc.

    Have fun!
     
    owenrg likes this.
  10. owenrg

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    I took the batteries out last night and took each down to under 5% then charged them up. Didn't get any errors today, but after 30% they drain real quick.

    I do have a hub on order after having to baby sit the batteries last night haha. Need to get some insulators and maybe the battery heater if I plan on having this thing outside long. It's cold in Idaho!

    Thanks for you help.
     
  11. Fink

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    Glad you were able to at least run them and put them through their paces. After draining them, following the charge from 5%, did you keep them at storage voltage or charge them back up? If it were me and I had easy access to a place where I could fly, I'd probably do that 2-3 more times just to really get a feel for what kind of shape they are in. What percentage of life does the app say they have?
     
  12. gray52

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    So does the charging hub full charge the batteries to 100%? I've only just got it and done the firmware update on it to stop it bricking the batteries. This may be why when I calibrate my batteries that the never show the full capacity, but it still takes 20min to full discharge them when flying for them to shut off. (Tb48)
     
  13. Fink

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    Yes, it will charge to 100% - mine are fully charged to around 4.30-4.32v/cell each time I use it. Mine didn't need a firmware update so that's a relief. To my knowledge, they haven't released an update on these since September.

    When you say "calibrate" your batteries, what do you mean?
     
  14. gray52

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    After firmware update, you have to fully charge the battery then run it down to 0% or until it shuts off, then recharge it. The battery is then calibrated to the new firmware and will give a more accurate reading when in flight. I just flown all my batteries down to 49% for storage over the holidays.
     
  15. ISP5557

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    OK this is the first I have heard of the "Running till shut down". I thought it was discharge to below 5%. I thought that running a battery down to 0 was the absolute worst thing you could do to the battery. I charge mine up to full and run down until it reads 5% and then land. I thought that was the directions. Has that changed?
     
  16. eldorado

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    This thread has been very helpful at clearing up a lot of information regarding the battery health. I have been attempting to set a SOP for battery charge/discharge and storage.
    On DJI site this statement looks like a typo:
    Storage Temperature Range
    Less than 3 months: -20° to 45° C
    More than 3 months: 22° C to 28° C​
    Should the latter temp range be - 22° C to 28° C? or does long term storage require +room temp conditions?
     
  17. Hans Devouassoux

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    Your battery should have Ver. 1.5.0.30 which was released on Dec. 19th, 2015. The latest version did not have an update for the battery themselves, just the aircraft (1.6.0.40).
     
  18. GadgetGuy

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    How do you check or verify the battery firmware version? It doesn't seem to be displayed in the About section in the DJI GO app, like the Aircraft, the RC, and the app version.