11.1 or 14.8v ?

[andrea]

I am looking for a battery... watching on forums, hobbyking and using Ecalc...
Some one say 11.1 v battery are better than 14.8 v ...I prefer 14.8 v
My goal would be to transport my camera (300 g ) with a reasonable flight time 10-15 min using 80% rule.

Here is my config:
Frame : Homemade x config. 550mm
Flight controller :MultiWii PRO MTK GPS Module
ESCs : 4x Afro ESC 30Amp
Motors : 4x Sunnysky V2216-13 650KV 20A 320W
Battery : from 4500 to 6000 Mah 3s or 4s


I made some calc but i dont'understand some things..
look the images below...
View attachment 22614 View attachment 22615
I choose 2 battery with the same Power ( that should be the important thing ) and the 4s has less flying time than the 3s ...but can load more weight...WHY?
Can anyone tell me what are the difference and what battery should be good for mi quadcopter?
Thanks a lot.

 

[eskil23]

You don't get watts by multiplying voltage with capacity. You'll get watthours. I believe 1 Wh is 3,6 kJ.

Yes, with 4s your motors will spinn faster (and thus give more thrust) but they will also pull more current (6.06 A vs. 4.86 A at optimum if I see right) and thus give you shorter flight time (specially since you have selected a battery with less capacity). With more thrust you can lift heavier batteries and that way get better flight time.

With 3S you can probably use larger props to get better lift (at the expense of flight time).

 

[PeteDee]

You should also change the weight to at least 2000g, 1000g is totally unrealistic.

 

[andrea]

Sorry You're right about Watts/hour.
Anyway i opted for two 4s battery connected in parallelo on this way i can get more flight time... probably 2x5000 Mah 20-30c
In HK there are a lot of batteries, i've seen 3 principal brands:
Turnigy nano-tech 5000mAh
ZIPPY 5000mAh Compact
Rhino 4900mAh
What are the best brand or can someone send me a link where is wrote the review? because i didn't find a lot on the web .

 

[J.T.]

Take a look at these andrea. http://www.hobbyking.com/hobbyking/...apacity_4S_5200mAh_Multi_Rotor_Lipo_Pack.html

They seem to work very well.

 

[PeteDee]

Yes they work well for a few flights and then die.

 

[Gary Seven]

Yes they work well for a few flights and then die.

LOL! Mine haven't quite died yet but they're definitely misbehaving at least compared to my Flightmax batteries. If anyone's interested see this old thread of mine:
http://multirotorforums.com/threads...e-for-mr-opinions-from-the-experienced.19682/

G7

 

[Bartman]

turnigy nano-tech...best bang for the buck buckaroos!

 

[andrea]

Ok at the end i opted for turnigy nano-tech 5000Mah:
http://www.hobbyking.com/hobbycity/store/uh_viewItem.asp?idProduct=17254