Need help understanding

J

Juan Guzman

Member
Just when I thought I had all the parts for my quad I ran into a question of my own that I could not answer. I plan on getting the betaflight F3 board and a 4 in 1 ESC. The question I have is whether or not I need to get a 25 or 35 amp ? reason I ask this is because the betaflight F3 board ESC inputs are rated at 25 amps and 30 Max. So how do I know whether or not that is going to be too much power being inputted into that flight controller by the ESC? Another question I have is, does the Motors that I choose have anything to do with the amps being put into the ESC? Same question with the battery? My worry is that I don't want to burn up any of my parts and I don't quite understand how all of these things come together. Example will my battery give too much power to the motor thus blowing the ESC or blowing the flight control. Another words how do I find the ratios of what will and will not work in terms of destroying the parts?
 
mozquito1

mozquito1

Well-Known Member
All governed by the esc. But the esc can draw to much power if you got big motors & ruin the battery. The higher C rating on the battery the better. Same with esc's, higher amps the better. But if you got small motors they can be supplied too much power. If you buy a 20amp esc.
Yes that is the rating but it will have a burst rate aswell. This is normally around 5-10 amps over for about ten seconds.
Any more then you can fry esc, motor & the battery can puff up.
It's all about balance. 20-25amp is OK for 4S batteries. So is 30 but be careful on motor size. You don't want to be supplying 30a to dys 1806 motors.
1806 =12-20amp on 3S. Emax 2205's =20-30 amp esc. On 3-4S
 
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Gyro Doctor

Gyro Doctor

Electronics Tech for over 45 years
Juan Guzman said:
So how do I know whether or not that is going to be too much power being inputted into that flight controller by the ESC?
Click to expand...

The flight controller isn't pulling any more or less current regardless of the ESC, battery, or motors. It does not provide any motor power to the ESC or the motors; it is simply decoding your command inputs it gets from the receiver and tempering that with responses from the gyro according to the PID settings. It sends pulses to each ESC which then controls how much power passes from the battery to the motor. Generally speaking, having an overrated ESC won't hurt anything and will just run cooler because if your motors are only asking for 20 amps average and the ESC is rated for 30 amps average then you're not even giving them a good workout. As far as how many amps is being supplied TO the motors, THAT is a function of how much current the motor is "asking for", NOT what the ESC is capable of providing (unless the motor asks for more than the ESC can handle). In other words, a motor that's only needing 20 amps at 11.1 volts can be hooked up to a one million amp 11.1 volt battery and will still only draw it's 20 amps. ;)
 
Jackson

Jackson

USA member at large
Juan Guzman said:
Another question I have is, does the Motors that I choose have anything to do with the amps being put into the ESC? Same question with the battery?
Click to expand...
The motors you choose will determine what size ESC you to provide the amps they need. Motors will usually have a chart showing amp loads at various voltages and prop sizes.

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A 20A ESC should work fine here. You can use a larger ESC for more head room if you like, note a larger ESC will still only provide what the motor calls for.
 
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