Tattu batteries arrived, but...

Discussion in 'Batteries & Power' started by Steve Maller, May 13, 2014.

  1. Steve Maller

    Steve Maller UAV Grief Counselor

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    I’m not sure they’re the ones I ordered. The batteries I received are labeled as “4200mAh” and “4500mAh”.

    I ordered two 10000mAh and two 16000mAh batteries. Does anybody know if the “pre-ordered” batteries they’re sending out are mis-labeled? These are definitely big enough to be the 10A and 16A Lipos I ordered, but I am not sure what to do. I’ve emailed them for confirmation.

    IMG_9908.jpg
     
  2. Mike Reid

    Mike Reid Member

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    I bet its a shipping thing, notice how they kept the watt hours below 100Wh? I think it might same on some "hazardous lipo handling fee"
     
  3. Ryan McCrae

    Ryan McCrae Member

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    Its the same thing Revoletrix does. To stay under the 100Wh issue.
     
  4. Steve Maller

    Steve Maller UAV Grief Counselor

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    Well, it turns out this was a deliberate thing, and the batteries were just mis-labeled to avert some sort of shipping, export or import requirements. That’s pretty shady, and I don’t like it. But at this point there’s nothing I can do about it.
     
  5. David burdeny

    David burdeny New Member

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    i just received 4 10000 mAh from foxtech with the same sort of packaging - kinda freaked me out at first....then i noticed the double shrink as you did.
     
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  6. Drew Kachurak

    Drew Kachurak Member

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    Steve - Let us know what you think of their batteries!
     
  7. Steve Maller

    Steve Maller UAV Grief Counselor

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    I will!
     
  8. Steve Maller

    Steve Maller UAV Grief Counselor

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    OK, first flight with the big Tattu 16000 LiPos.
    Strapped two of them to my X8 with a 5 pound dumbbell underneath, for a AUW of about 25 pounds.
    I’m using KDE 4012 motors with 16” CF props.
    Those batteries are really heavy!
    Lifted off just fine, and it felt plenty nimble enough.
    After almost 20 minutes in the air, a local police officer had stopped by and started chatting me up (with my headphones in I could barely hear him) so I decided to land and talk to him. He was super friendly, complimentary and curious, and we had a nice chat.

    The copter’s performance was awesome. Here’s the GPX file header. I was able to punch the throttle several times, and do a fast descent with plenty of braking overhead, even after 16-18 minutes in the air. I spent a good deal of time (maybe 10 minutes) in AH/PH because my fingers were getting tired! Again, the BL cooling on the MK board did a great job of keeping things nice and comfy, even though the ambient temp was 91°F and I spent a lot of time in a dead hover.

    So it seems I had about 20% or more capacity remaining when I landed, and the voltage was still at around 21VDC.

    MK Version: FC HW:2.5 SW:2.06a + NC HW:2.0 SW:2.06b BL:V3
    Flight date: 5/14/2014 2:28:40 PM
    Flight time: 2:28:40 PM.4 - 2:48:23 PM.2 (1182 secs, 00:19:42)
    Batt. time : 1179 secs, 00:19:39
    Start Lat./Lon. : 37.5904042 / -122.3585385
    Elevation(GPS) : 0 0.15 5.314 m (min/avg/max)
    Altitude(Barom.): -0.15 5.88 15.75 m
    Vertical speed : -2.45 -0.01 3.96 m/s
    Max speed : 15 km/h
    Max target dist.: 5.4 m
    Max distance/LOS: 32.1 m / 34.1 m
    Sats : 10 12 13
    Voltage : min. 20.7, max. 24.2 V
    Current : 0.5 82 124.3 A
    Wattage : 11 1847 2703.8 W
    Capacity: 26907 mAh

    Motor1: 0.0 10.1 15.3 A Temp: 47 54 60 °C
    Motor2: 0.0 8.5 13.7 A Temp: 39 46 50 °C
    Motor3: 0.0 10.7 16.4 A Temp: 42 50 55 °C
    Motor4: 0.0 11.5 17.8 A Temp: 42 59 64 °C
    Motor5: 0.0 12.4 18.3 A Temp: 40 54 64 °C
    Motor6: 0.0 10.6 15.9 A Temp: 42 61 67 °C
    Motor7: 0.0 5.9 10.3 A Temp: 47 57 62 °C
    Motor8: 0.0 10.6 16.1 A Temp: 41 52 58 °C

    Magnet Field: 92 104 117 % (ok)
    Magnet Inclination: 52 56 65 deg

    No errors found ;)
     
  9. Michael McVay

    Michael McVay Active Member

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    Thanks for the details on the batteries. They are actually an exhibitor at AUVSI 2014 in Orlando. Tomorrow is the last day of the show and I think I will stop by their booth after seeing your results with them. If its not too much trouble, would you please post how many mAh of charge goes back into the batteries when you charge them up? I have found the MK capacity numbers to be a little off. I know you can calibrate your flight control to increase the accuracy, but I have always just left mine conservative. Thanks!
     
  10. Steve Maller

    Steve Maller UAV Grief Counselor

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    I will recharge them tomorrow, but not until the afternoon.
     
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  11. Paul conto

    Paul conto Member

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    What's new about the tattu batteries from the other gens aces batteries, as it is they have a lower C rating then the original 15vs25. Is it a new mix or something? About the shift to 6S system so I need new batteries and with quadrocopter being out of large 6S I've been looking elsewhere and used to use gens aces religiously.
     
  12. Steve Maller

    Steve Maller UAV Grief Counselor

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    I can’t address anything about GensAce vs. Tattu. Some have said that there are some changes, but I haven’t used GensAce, so I won’t be able to comment. Somebody suggested using Pulse batteries from HeliDirect, although their big 6S packs are out of stock right now, too.
     
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  13. Steve Maller

    Steve Maller UAV Grief Counselor

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    I recharged the two 16000 batteries today, and got these numbers:. So it appears that the batteries consumed 28,731 mAh according to the charger, and 26,907 mAh according to the copter, about a 6% difference. I do know that one of my BLs is miscalibrated, and is reporting about 40-50% lower current than it should be reporting, so maybe that accounts for the difference. Not sure.

    IMG_9926.jpg

    And of interest, the internal resistance of these batteries is very, very low.

    IMG_9927.jpg
     
  14. Michael McVay

    Michael McVay Active Member

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    Thanks for posting this Steve. I would have guessed the recharge to be less than the consumed total from the FC but maybe your one BL is skewing the numbers. IR of 3 is great...looks like you have good batteries!

    One thing I have noticed as part of tracking all my charge cycles is that if you discharge a battery further the IR tends to be lower on the recharge cycle. Not sure if the energy / lithium left in the battery (even at a store charge level) cause a little extra IR during the charge or if it is another reason. If I run a battery down to 55-60% flying and leave it there the IR on the next charge might be a little higher than if I run a battery to 25% and leave it there until the next charge. From that regard, it seems to make sense to fly the batteries down to 20-30% instead of landing at 50 or 60% after short flights.

    Has anyone else who tracks their charge cycles noticed a similar pattern on slight variations in IR?
     
  15. Gary Haynes

    Gary Haynes Administrator
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    A mix of brands and sizes, almost always flown to 20-25% and the IR's are very consistent. I most of the battery data in my flight log so that I can 'maybe' spot trends to determine when a battery might be departing it's earthly life.
     
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  16. Steve Maller

    Steve Maller UAV Grief Counselor

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  17. Graydon Tranquilla

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    You are correct....


    Before the TDG regulations kicked in on LiPo battery capacity limits for airfreight some manufacturers were inclined to oversell their battery capacities - less so now! Hobbyking International and it's customers suffered significantly as a consequence of somewhat similar LiPo related issues this past year.

    From what I understand.... the potential risk of instability leading to LiPo fire/explosion can be greatly reduced by shipping at 50% charge or even less.....(more stable).... but the total fuel to continue a LiPo fire remains the same in line with the total mah capacity (lithium content).
     
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  18. Tristan Twisselman

    Tristan Twisselman Active Member

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    Steve what are your final thoughts? I am switching from freefly to these and I actually just became a distributor if you or anyone else need some. I think they are comparable/basically the same thing as pulse just different labels.
     
  19. Steve Maller

    Steve Maller UAV Grief Counselor

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    The six 10A Tattu batteries I have are bulletproof. Love 'em.
     

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