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How to choose power of ESC? Manufacturer of motors said that maximum amperes for this motor is 40A. Does it mean that I need to put separate 40A ESC for each motor or 160A 4-in-1 ESC? How to choose the much effective ESC for my motor?

What is the difference between BLHeli32 and BLHeli_S?

Should I choose much powerful FC (i.e. F722 instead of F405) for ESC's with a lot of amperes?

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  • $\begingroup$ The voting on this site works best when you only ask one question at a time $\endgroup$ Jul 14, 2023 at 10:27

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Sustained motor loads are generally a lot lower than this. In a full power punch-out (on a 5" race drone), you might pull 80amps total, 20amps per motor. If a 6s 1000mAh battery lasts 3 minutes, it is averaging 20amps total, only 5 amps per motor.

A 40amp 4-in-1 ESC is 40amps per motor. Advertisers haven't tried representing it as a 160amp esc yet.

The reason 40, 50 and even 60amp ESCs are used is that you can pull very high peak loads when one of the motors is stalled by an obstruction (for example, when attempting to take off after a crash). A motor has enough mass to be overloaded for a second or two, but the ESC will overheat very quickly - and burning a motor is cheaper than burning the ESC (which often damages the FC).

How much you need probably depends on your flying (or rather crashing) style. After a crash, do you risk breaking props and burning a motor by attempt to take off from where you land, or play it safe and walk to recover it?

BLHeli32 is more advanced, and is where new features will appear (and have been for the last few years). Probably the most significant for me is being able to reverse a motor from within Betaflight.

You don't need a faster processor in the flight controller for a higher amp ESC. The two are unrelated.

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  • $\begingroup$ So, can I just choose 40A 4-in-1 ESC and be happy? $\endgroup$
    – Robotex
    Jul 19, 2023 at 14:25
  • $\begingroup$ Yes, I think 40A is perfectly adequate for a 5" drone. I wouldn't spend extra on a more powerful ESC, but if that's all you can find then it's OK too. $\endgroup$ Jul 24, 2023 at 7:58
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Amps: You will need 4x that amp or 1 ESC per motor for the motor. Look into how they tested the motor and what that number represents (40a could be fail or sustained use at time intervals or ??).

For amps - in real life, I have 2 formats I know very well, 5" and 3" freestyle.

5" hovers around 5-15A, cooking is 40-70A, punch is 80+ having hit 120A+ (2204, 4s, agro props, 100c battery)

3" (200g) Hovers 1-3A, cooking is 10-20A+, punch is 40-50A. I have hit 80AH on a 350g 3".

How to choose the much effective ESC for my motor?

Don't - your first builds will burn up quickly (if you are scratch building and learning). Don't go too cheap; strike in the middle; a good solid choice from GetFPV or similar will get you started. Look at others' builds and follow.

What is the difference between BLHeli32 and BLHeli_S?

I don't know. I don't care. Never did. Avoid looking into ESC and flashing, which is later in the drone game. Model your build after someone else's and avoid the technical rathole.

I have used and cooked hundreds of sets of ESCs; only 1x did I ever care about the type. You may be different, but your first build does not care at an early stage.

Should I choose much powerful FC (i.e. F722 instead of F405) for ESC's with a lot of amperes?

Go for amps. Go wide on amps, and have headroom. Two big reasons: First is less chance of damage. Second, some ESCs may act funny (cook, smoke, or self-limit) if you push them too hard. Avoid anything unpredictable... this will probably happen at the least good time.

Higher timing is only noticeable at the fringe; if you are starting in the hobby, you are 1-2 years away from pretending to notice that difference.

I choose ESCs by AMP rating first, then "make" (companies I still trust), then all the tech specs. I would rather have something reliable than sketchy with a better chip. Until you hit the finals in racing, you will never know the difference.

If you are not racing, freestyle, gapping, or getting on with your game, everything becomes simpler and needs fewer amps. Those applications are out of my domain. I only design/cut/fly fast FPV drones.

Enjoy the flights first—lots to learn.

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  • $\begingroup$ > your first builds will burn up quickly first build is success and still alive :) $\endgroup$
    – Robotex
    Jul 18, 2023 at 20:36
  • $\begingroup$ @Robotex, I never mentioned the next phase. Pivot to the brands and specs you like, and stabilize your favorite builds. Then, once stable, you mirror the build, then triple. I often show up to a session with 3+ of just one drone. I also have the units 100% modular, and almost any component can be swapped in the field. $\endgroup$
    – FunHog.me
    Jul 20, 2023 at 14:36

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