camera drone build

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miky94

Well-Known Member
Thanks for the links.
I can't find official specs of this cell, some site says 30A continuous per cell, some other says 20A, probably someone cheats and 30A is the burst discharge current, anyway I can always use 4S3P.
From motors charts I've seen , increasing linearly the throttle the current draw always increases exponentially, so if hover is under 50% throttle I can fly quiet and use burst only for short accelerations.
another thing I never understood: how much time must pass between a burst discharge an another? Is about batteries temperatures?
 
wafflejock

wafflejock

Well-Known Member
miky94 said:
Thanks for the links.
I can't find official specs of this cell, some site says 30A continuous per cell, some other says 20A, probably someone cheats and 30A is the burst discharge current, anyway I can always use 4S3P.
From motors charts I've seen , increasing linearly the throttle the current draw always increases exponentially, so if hover is under 50% throttle I can fly quiet and use burst only for short accelerations.
another thing I never understood: how much time must pass between a burst discharge an another? Is about batteries temperatures?
Click to expand...
Yeah totally the batteries have "internal resistance" that causes heat in the cells themselves and increasing heat increases resistance in general so this is sort of a snowball type thing when under load, the longer under load the more the heat will build up, this also seems to be an issue with some of the huge LiPo packs (multistar 6S) people seem to have issues with 1 or 2 cells in the pack dying my guess is just so much heat build up and not as much surface area for all the cells to dissipate the heat (I'm not a chemist or electrician though so this all gets into very fuzzy understanding for me too) . There is also some effect I imagine from the flow of the lithium ions themselves but yah that's just too deep in the weeds for me to think about :)
 
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miky94

Well-Known Member
A diy cooling system would not make sense so I'd probably better use 3P , 4S should increase the current draw but having more lift I hope I could fly at lower throttle, later I'll test my cheap 2212 920kv motors to see how much far they are compared to the DJI
 
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miky94

Well-Known Member
Ok I finally find out an efficient configuration on 6S which draws only a little bit more than 7A at 100% throttle
So looking for a 30A (7 x 4 = 28) 6S 4in1 ESC I find out these which have 5V BEC:
https://www.ebay.com/itm/Excelvan-2...-ESC-for-FPV-RC-Drone-Quadcopter/202350514199
https://it.aliexpress.com/item/BS43...S-firmware-Dshot-4x30A-F3-F4/32918787596.html
I think I'll solder a jst socket connector on the FC so that I can esaily change in future.
do I need a special configuration on the firmware for low kv motors and Li-Ion cells which have lower minimum voltage?
 
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miky94

Well-Known Member
I calculated a total weight near 1500g, and according to motor test data I'll draw about 5A to hover, though I'll use 1345 props instead of 1340 in test data, but carbon fiber and t-style so lighter.
considering that at 75% throttle I'll pull about twice the drone's weight drawing about 15A and I'm not going to push throttle much more than that, do you think that a Li-Ion with a constant discharge current of 15A would be enough?
I would have anyway an higher peak discharge current, which on Li-Ion lasts even a minute. or what is the minimum constant discharge current I should look for?
 
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Christ1@n

Well-Known Member
RENOV8R said:
Too many variables, too many questions. Especially when you haven't determined what frame you are going to be using. And that's the basis of any build, match the components to the type and weight of the frame. But to answer your ESC question, I use single ESCs on most of my builds, easier and cheaper to replace I than all 4. Here's a 300mm medium/long range build I'm in the middle of using single ESCs:
View attachment 4717
Click to expand...

What kind of frame is this? Nice with the rubber protections on the arms!
 
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