flight duration vs Amps

[erikhaha]

Here is a plot that I made, comparing flight duration, in minutes vs amps drawn by the motor.

Any thoughts as to how accurate this may be?

[BMatthews]

That's fine but you need to figure out your average current and how long the slowly dropping voltage from the battery can support that level of current. If you need that full 15 amps and the battery can only supplly 15 and more for the first half of the run then full throttle performance will fall from that point on.

From there it comes down to your tolerance for the failing performance level as the battery drains.

The good news is that if the voltage lowers to where you can't pump the max current at least your duration is extended.... :D

[Andy W]

I pinned a note to the back of my soldering workstation, where I also store a lot of my packs.. seconds per A per USABLE Ah - in 10A steps. It's a quick guide for me to reference when I'm picking a pack out for an application. The key is USABLE capacity, at the expected load, and I am familiar enough to be able to take a swag at it.

Mine is scribbled on a post-it-note, and it took all of a minute to produce - 3600 divided by amps -

Amps Seconds
10 360
20 180
30 120
40 90
50 72
60 60
70 51
80 45
90 40
100 36
110 33
120 30
130 28
140 26
150 24



The key is to use that as a general guide for the first flights, but to fly a bit less on your first flight(s), and see how much capacity the battery takes to recharge.
..a