This is another conversation that came up today and I'm in a quizzical mood 

Betaflight defaults to 1850 for max_throttle of course, and the FAQ clear states:

Quote:The default max_throttle of 1850 comes from MultiWii and is a SAFE max value for ALL ESCs.

Now when I read the word safe, the obvious question is BUT what if I do put it up to 2000, anybody do or tried it?

I always do. You should calibrate ESCs with widest throttle range. I go 1000-2000, calibrate and then set throttle min so my motors start up smoothly. With blheli_s I added 20-30us after finding start point. I don't have any idea if it's the right method but it works

(27-Aug-2016, 03:05 PM)Konrad Stepanajtys Wrote: I always do. You should calibrate ESCs with widest throttle range. I go 1000-2000, calibrate and then set throttle min so my motors start up smoothly. With blheli_s I added 20-30us after finding start point. I don't have any idea if it's the right method but it works

Many thanks Konrad, I'm good with tuning my min_throttle but have always left max_throttle as default and now I'm thinking I'm losing out on (not that I'm missing) some power. However there must be a reason why Betaflight still sets it at that or is it as simple as ensuring widest compatibility.

yea i think the 1850 is to make sure everyone can reach max throttle so better compatibility, but I also set it to 2000

(27-Aug-2016, 03:07 PM)Sigloss Wrote: Many thanks Konrad, I'm good with tuning my min_throttle but have always left max_throttle as default and now I'm thinking I'm losing out on (not that I'm missing) some power. However there must be a reason why Betaflight still sets it at that or is it as simple as ensuring widest compatibility.

Yes, you are missing power, I had flown my NOX with 1850 for some time after some quick setup I made in a hurry and had no time to look into that properly for some time. After fixing this I found there was a significant difference during flight.

I am the black sheep then, I set my max to 1980..LOL, I read that you need to allow a little headroom for the FC to keep working properly at or close to max throttle.

(27-Aug-2016, 09:43 PM)BigglesFPV Wrote: I am the black sheep then, I set my max to 1980..LOL, I read that you need to allow a little headroom for the FC to keep working properly at or close to max throttle.

I also set mine to 1990

(27-Aug-2016, 09:43 PM)BigglesFPV Wrote: I am the black sheep then, I set my max to 1980..LOL, I read that you need to allow a little headroom for the FC to keep working properly at or close to max throttle.

Wasn't that blheli "deadband" removed in 14.5 (or something close)? That was 25us BTW ;p

You're suppose to "find" your Max throttle. At least that's what I do.
Take the props off
Put on a 3s lipo
Throttle up each motor in BF/CF motor tab
Listen for the sound of the motor to change @ max throttle
Use up and down arrow keys to adjust motor speed.
Write down the value where the motor sound doesn't change anymore

Generally speaking you want to set your max throttle based on the weakest motor, this way @ full throttle none of your motors hit a deadband before the other.

For example after doing the motor tab test above your results are:
M1 = 1980
M2 = 1995
M3 = 1990
M4 = 1978

Then your max throttle should be set to 1978

For more info:

trojanGoat, great post, love it when I learn method to madness

+1 to trojanGoat's explanation. The video linked is from Joshua Bardwell and is one of the best tutorials on motor/esc calibration. Joshua also has a mountain of great information and tutorials on his youtube channel (https://www.youtube.com/channel/UCX3eufn...IkKHZn8KSQ) and across the rcgroups forums.

I've discovered that most of my motors max out between 1940 and 1980. It depends not only on the motor, but on the ESC and perhaps the propeller. Generally because I am paranoid, I set my max throttle about 10 below what I measure.

Intersting thread! Was looking for answers on this topic and came here!

I flashed betaflight 3 last weekend and i noticed that my max_throttle defaulted at 2000. Okay, i thought, Boris knows best. But when i went out to fly and gave her a good punchout i noticed that it was not smooth at all. I had erratic jerky movements in all axis! I lowered the max_throttle to the safe and oldscool 1850 and all was ok again.

I think that the latest esc firmware can handle a higher max_throttle than 'in the olden days' but i am convinced that the FC still needs a little hadroom to control the craft when at full throttle.
As soon as i fix my broken vtx, i'll go out and fly and raise my max_throttle but i will not max it out at 2000. I think i'll go to something like 1950 or so.

Can't just change your max_throttle without also recalibrating the ESC's.

If you calibrate escs to what is set in configurator, you will not lose power. You might miss out a bit on resolution but i doubt that's really noticeable.

But as a heads up: you are NOT ALLOWED to set max throttle in configurator higher than what your escs are calibrated to - this will lead to FULL POWER DEATHROLLS with all its possibly dangerous consequences.

On the other hand, setting max throttle in configurator lower than what your escs are cal'd to is a legitimate way to cap max power output of your quad.

EDIT: This my post is not regarding blheli special cases - but is actually what i learned from those reported issues.
For old blheli firmwares, it's important to know/not exceed the real max throttle w/o deadzone, like trojanGoat said.