Batteries and power distribution questions

[david.scarbrow]

I am in the midst of putting 4 Axi 2814/22 motors/Turnigy 30A Plush ESC combination onto a Bagheera 600 airframe and driven by a Wookong-M FC. In the absence of any (sound and/or unsound) advice that I can get locally what batterie(s) should I use for this setup ? I am aware of the voltage requirement limitations of the Wookong-M and/but that a 4s Lipo would serve me and the motors better in terms of eeficiency, effectiveness and time in the air. Additionally what is the best way to distribute the power to the motors, esc and the Mookong-m with this set-up ?

 

[Gunter]

Hi David, totally aside from your post, I'm in Tadley and hook up with a couple of local guys occasionally for flying and the odd chat! Why not say hi on homegrowndrones.co.uk

Cheers,

Gunter.

 

[jes1111]

As long as you're in possesion of all the relevant numbers, this is a great tool for answering questions like that: http://www.ecalc.ch/xcoptercalc_e.htm?ecalc

 

[david.scarbrow]

Gunter, hey Tadley is only around 15 miles or so from where I live in Hook (just outside of B'stoke). Great idea to meet up with you guys to compare notes, etc. but don't expect too much from me...I'm fairly new to all this rotary wing stuff and at the beginning of a very steep learning curve. For the past 2 months I have been learning on an Xaircraft 650 (Version 1) and I have bent it a few times losing bits of carbon and fibre on the way. My new airframe and FC will initially be for Sunday best with a view to eventually use it for everyday use when (if) I get good at it. All the parts for this quad should be with me by next week. Jes1111, I'll have a crack at that xcoptercalc application...it looks interesting...will it help me understand better my battery requirements ?

 

[Gunter]

Don't worry David, I'm on my first build and also doing the learning curve thing!

 

[Bartman]

David,
You've got to build a circuit for the power to go from the batteries to the individual ESC's. It starts with two loops, one positive and one negative. Someone commented that the negative loop shouldn't be a closed loop so it doesn't hurt anything to incorporate that detail into the layout. The loops should be large enough to go around the outside of the flight electronics. If you're using one battery pack then you need to also incorporate one set of battery leads into your loops. The loops for a quad should probably be 12 or 14 guage wire with individual 16 guage branches going to the esc's. I used 10 AWG for the loops and 16 AWG to the motors for an Okto heavy lift with two sets of battery leads powering the whole shebang.
View attachment 937

To tie the branches into the loops just bare about an inch of wire, tin it, and then solder the branch wire onto the surface of the heavier loop wire.

Maybe the DJI doesn't require a power distribution loop like this?

Hope that helps.

Bart

 

[david.scarbrow]

Bart, thankyou for that...I guess it will have to be something like your loop design...it is relatively easy to put together and I can build it to an exact fit...it also isn't that far removed from pre-manufactured power distribution boards from..eg...MK, ArduCopter, etc.. The Wookong-W kit arrives tomorrow...maybe there will be something in print in the package that discusses power distribution.

 

[jes1111]

that xcoptercalc application...it looks interesting...will it help me understand better my battery requirements ?

If you persist with it will help you understand life, the universe and everything