Battery percentage reducing fast

ArduCopter Copter 4.5
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1

Hi all, I am using Cube Orange with a 7000mAh 3s Lipo Battery and built a quadcopter in an S500 frame with emax motors.

Whenever I enable the battery monitor to 4 (voltage and current), the percentage is reduced from 100 to 0 within 2 minutes.

So I followed Power Monitor/Module Configuration in Mission Planner — Copter documentation (ardupilot.org) and tried in the same manner… but no use… the only improvement is the time of percentage reduction is increased from 2 minutes to 12-13 minutes.

Note: 1. We armed the drone with propellers only to set the battery voltage and current.
Note: 2. We left the drone idle without arming it to check the reduction in battery percentage.
Note: 3. The battery voltage is displayed properly.

2

Your current measurement needs to be calibrated. It has two parameters:

  • a current offset (Aditive parameter)
  • a current gain (multiplicative parameter)

Both need to be correctly set. But because readings at low currents are highly inaccurate, you should calibrate at nominal (expected during normal operation) currents.

For a small copter investing in a multimeter will eliminate the guesswork, and trial and error of other approaches that depend on the current measurement accuracy of the battery charger.

And you need to do this correctly before doing any magfit flights.

3

Thank you @amilcarlucas can you please share the recommended documentation to refer to?

We calibrated using power analyser and current at 10.05A (pervolt)

We followed the same documentation given below (no changes in the steps)
Power Monitor/Module Configuration in Mission Planner — Copter documentation (ardupilot.org)

4
  1. At what current level did you calibrate at (in Ampere)?
  2. How much current are you expecting to consume at hover?
  3. Did you calibrate at a single operating point, or did you used multiple?
  4. Are you using ArduPilot Methodic Configuration sequence?
5

  1. An edit [We calibrated using power analyser and current at 10.05A (pervolt)]
    It is not 10.05A prevolt… it 10.05A current
    and Amperes per volt is around 3.45A

  2. If you have refered the video in the link…I have not hovered the drone insted I reversed the propeller so that it won’t lift the drone instead it push the drone down.
    So when the drone is armed and consuming 10.05A current… the Amperes per volt is around 3.45A

  3. As I am an newbie I did not get the 3rd point.

  4. No I am no using that.

Kindly refer the below video so that you can get an idea what actually I did to calibrate
ArduCopter Battery Voltage & Current Monitor Calibration (youtube.com)

Thankyou and appreciate your patience

6
  1. OK, that is clear now.
  2. How much does the drone weight? What does the Ampere meter read when it is pushing down it’s own weight in Kg? This can be easily be done by putting the vehicle on a scale (with reversed propellers) and throttling it slowly up (using mission planner motor test screen) until the scale reads double the weight of the vehicle.
  3. Do you know what y = m*x + b means? Do you know what a linear regression is?
  4. You should use it, especially because you are a newbie. It will prevent you from doing certain mistakes.
1 Like
7

Hello, @amilcarlucas, as I have crashed the drone few parts are broken and it takes some time to replace. I assure you I will refer to the documentation and the GitHub repositories and try to solve the problem as soon as possible.

I am not sure about the drone’s weight exactly, when I lift it in hand it feels around 1.7 kg to 2 kg. Once I receive the new arm and a set of props I’ll try the 2nd point.

Yes sir I know linear regression and got the point, I’ll measure the current and Amperes per volt for the increase in every 2A of current, plot the graph, and share the graph with you soon.

Kindly keep your support on me in the future. We will catch-up soon