When the battery is plugged in, the flight controller isn’t getting any power? Don’t worry; you are exactly in the right place! I did full research on this topic, and here’s what I found:
Flight controllers (FCs) don’t get power from the battery, most likely because the voltage regulators or some circuit parts could have burned. However, the issue can also be due to the speed controllers’ lack of an in-built battery eliminator circuit.
Read on to learn the reasons in detail and what you can do to fix the issue!
Flight Controller Not Getting Power From Battery: Possible Causes & What To Do
#1. Voltage Regulator Is Burned
There’s no sign of turning on when you plug in the flight controller to the flight batteries. However, if you plug your FC into the computer, it does show the signs of turning on. And if that’s the case, you have likely burned the voltage regulator in your Flight controller.
The function of the voltage regulator is to regulate the power from the battery and reduce it to 5V. This is done to appropriately power the accessories on the flight controller.
Also, there are other regulators like 3.3V powering the MCU. What is an MCU? It is the biggest square chip you can find on the board.
What To Do? So if the voltage regulators have burned and hindering the power supply to the FC, you must remove them from the board.
And then, you can use an external 5V BEC to power the flight controller. Does your ESC have a 5V BEC? If thets the case, you can also use that for this purpose.
Note that if you are trying to use an external BEC, ensure it is at least rated for 2A.
What is a BEC? BEC stands for Battery Eliminator Circuit, and it is simply an electronic voltage regulator. It is mainly used in radio-controlled items in which separate voltage is needed to power RC equipment.
How To Know If The Voltage Regulator Has Burned?
First things first, you need to grab a multimeter. Don’t have one? See a selection here on Amazon.
Then, put your multimeter in continuity mode. (Basically, the beeping sign, will tell you when you can touch the two ends of the multimeter together)
Now, find the voltage regulator pads and test them to see if there’s a short, using the multimeter. If there’s no short, it is possibly a good indication that your particular voltage regulator is not burned yet.
#2. Schottky Diode Is Burned
Is the Schottky Diode on your flight controller burned? Generally speaking, it is one of the most common things that gets burnt out on a flight controller.
This diode allows two lots of five volts to come into the board and not touch each other.
Check out my article: Do drones break easily?
For example, the voltage from the 5-volt regulator and 5 volts from the USB, so you don’t have to face any problems.
What To Do? Check to see if the diode is ok.
To do this you will need your multimeter and set it to continuity mode.
You can also watch this video to learn more about how to test the diode using a multimeter:
#3. Problem With The Speed Controller
Previously, when multirotors first began, the speed controllers had an in-built battery eliminator circuit. The battery eliminator circuit supplies the 5V to the flight controller. And that way, the flight controller gets the power to function properly.
If your flight controller is running smoothly on the USB cable, it is mostly because the USB supplies the needed 5V to power the flight controller.
Suppose you have an ESC that has the built-in eliminator circuit, in this case you can just attach the three wires from the ESC to the motor connection on the flight controller. That way, you can connect the speed controller, power the motor, and supply the 5 volts to the flight controller.
All the 5-volt pins and all the ground pins on the flight controller are connected with each other. So whenever one part gets the 5 volt power, the rest is powered too!
Therefore, the 5 volts from the in-built battery eliminator circuit powers the radio receiver and any accessories plugged into the flight controller.
But, the problem begins when you have an ESC that doesn’t have a built-in battery eliminator circuit. The battery eliminator circuit tends to produce a lot of heat. And it is not ideal to allow more heat to get into the ESC, which is already working at a hard rate.
What To Do? You would still have to plug the ESC into the motor output on the flight controller. But in addition, you need to use a separate battery eliminator circuit.
I highly recommend you watch this video. I have set it to the exact timing where the video host starts explaining the ESC and a separate battery eliminator circuit set-up with a diagram.
In short, when the flight controller is not getting power from the battery, there could be two reasons. First, any circuit parts like the voltage regulator could have burned or been damaged. Or, there is no presence of in-built systems that can support the usage of power from the battery.
When the circuit part is burned, you need to repair or replace that part. And when there is a lack of support to the battery power, you can install a separate battery eliminator circuit.
Lastly, if nothing really works out, then you have no other choice than to get a new flight controller circuit. But I hope your problem is solved without spending a lot of bucks!
So that’s it! If you found this guide helpful please don’t forget to share it with others. Thanks 🙂
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