3 | Measure battery lifetime with a voltage divider

This video explains how you can estimate the flight time of your quadcopter by measuring the voltage of your battery. You will learn how to calculate and build a voltage divider allowing your Teensy to measure voltages up to 16 Volts.
The purpose of this video series is to learn the basics behind a quadcopter drone and enable you to build one yourself, by dividing this challenging project in several easy-to-understand parts. You use the capable Teensy 4.0 microcontroller together with the easy-to-use Arduino language.
Full code available on GitHub: github.com/CarbonAeronautics

[@robertparenton7470]

Thank You! From Frisco, Texas.

[@619dsk]

The output 5volts from monitor is nothing but 5v from the input teensy chip ?

[@rajasriram6578]

high how did you plot this graph?

[@sahinduran66]

Hello, I am using a voltage divider just like you for reading battery voltage. However, the problem is that when the motors are running with props, voltage drop occurs at the battery output. For example I start with %80 battery capacity, when motors are loaded it says that the battery has %50 capacity (for example). %100 corresponds to 12.6V, where %0 battery means 10.6V. So 2Volts is scaled to %100. If the battery voltage drops 0.6volt, my gauge tells differently. Is there any way to fix it?

[@Catnugget76]

pretty late answer, but you could use a sliding window filter to remove those voltage drops. And perhaps use capacitors and a schottky diode to protect against reverse polarity

[@HaiderAli-nm1oh]

strange why did u multiplied with 5 with 3.3 ? , shouldnt ur equation be | voltage_out= (3.3/1023) * analog_val ?