Advice on battery (quad-copter)

Projects General Guidance
21

The problem with the table in the article when it relates to efficiency is that is only compares the motor at max thrust. The efficiency will look really strange because the power to generate a certain thrust is going up disproportionately. What they need is a table of amp draw at a given thrust level. How efficient is the 4s or 5s setup at the same thrust levels as the 3s or 2s.

In my testing though the lower voltage setups are still slightly ahead at a given thrust level, that may be because we are using motors designed for lower voltages?

I found 10x4.5 slow-fly props with 2212 motors draw about 1.3A at 12v AT 150grams thrust but they get very inefficient as you try and spin them faster. Some props meant for higher speed may maintain better efficiency at higher rpms and real world flight than one that looks better in a static test. There's just soo many variables.

22

After some more research it seems the low kv motors would be best for my design, to provide an adequate flight time, as well as a greater amount of torque to function. The speed of the craft may or may not be an issue but that can only be tested once I have the first model built. Thanks for all the info, especially the links for useful sites. As I said before the low kv motors last use less voltage, while outputting a greater amount of torque thus are more efficient in flight time, on the other hand high kv motors use more energy, output less torque but output an immense amount of speed, far greater than low kv motors, thus are more efficient in speed. Overall, when selecting a motor one needs to consider if they value speed and agility or flight time and carrying weight in order to select the proper motor/s.