Recently, I got my FIRST 6s Lipos and found out REAL quick (even with motor scaling) it’s another world… after the crash, I went through the build, and installed a different (not new) set of motors (same size, same KV). I was flying the rest of the 6s (I only got 55 seconds into it)… nice, easy, nothing crazy.. noticed I was getting substantial longer flight with almost no voltage drop compared to my beat up 4s 1300s…just as the voltage was hitting 3.5, the quad dips to one side and falls out of the sky(only maybe 8-10 feet on to grass).. I’m like WTF!?!
I pick it up, no smoke, motors spun free.. but one was HOT!!!
Now, when I installed these I checked ALL the screws for continuity to the esc pads because they are “blind”, u can’t see well into the windings.. I even checked AFTER the drop..
Apparently, it was “it’s time to go”.. for one reason or another.. this posed 2 questions, ESPECIALLY since I fly over water ALOT (I may re think this)..
One, how may motors just “fail” in flight?.. I can understand bearings going bad.. but just out of the blue??
And second, did the added voltage from the 6s accentuate any, flaws or possible damage to my component from prior crashes?? All my components are rated for 6s.. but are these components more “sensitive” at this higher voltage ??
I have had RXSRs fail mid flight (hence me going to crossfire).. but I never gave thought to motors failing out of no where.. from crashing YES.. but a “easy Cruze” not so much….

Yes, 6S does put extra stress on components, especially ones that my be a bit iffy in the first place.

This is one reason I don't fly over large bodies of water and another reason that I'm nervous about flying over any dense wooded areas. You always have to keep in mind that component / hardware failure could happen at any time which is something out of your control. If you fly over water you just have to be prepared that you could lose your whole quad in the event of such a failure. People who do that are usually fine taking that gamble. Unfortunately I'm not.

A 6S motor with lower KV will use thinner wire with more windings to carry a high voltage but lower current through the windings to achieve similar rotational speed as a 4S motor.

So if KV of a 6S motor is carefully selected we can keep the same performance of a 4S motor. But then this is also where we push the limits on 6S by playing with the KV to get more speed/rpm out of the same size motor than what we could on 4S.

Your 6S quad will experience less sag but should not be any faster than a 4S quad but it feels like its on steroids because it does not get tired.

You can avoid sag on 4S but then you need a higher C rating lipo and higher MAH lipo to provide enough current to the hungry setup. But then that adds much more weight. This is a different discussion.

With 6S (higher) voltage you can push more current through the motors but then you are more susceptible to voltage spikes which will either kill the ESC or cause the ESC to kill your motor.

Now what kills a motor is not voltage, rather its the high current you feed through it when you push it which is when you land and you feel your motors hot.

Some argue with 6S we are not pushing too much current in the system, but then why do our 6S packs have the same MAH ratings as our 4S packs and where did the current stored go?

So for a 6S setup we need better quality components than a 4S setup as Snow mentioned because we now have the ability to push the quad further and further to the point where we stress the components more than we can on a 4S setup.

Yes, the realization of “total loss” was always in the back of my mind, but never gave it much thought as I usually flew a “low cost-beat to hell” set up over water.
As I have progressed and my components / quads became .. a bit better quality and more money.. I started to “re think” things.. now my “fishing quad” is one of those “low cost” things.. it’s my old wizard220, but it does hold sentimental value (first fpv quad)… it has been through hell and back… I may just buy a source one, and swap it… retire the old wizard…
But this does make me think, IF I am gonna progress with 6s… it should be with a “clean” build that’s HASNT been fed asphalt / concrete whenever it gets flown..

I run 6s on my 5". I use 1850kV motors, but I have been thinking about trying 1700kV to see if I can get even longer flight times. I don't do the crazy punch-outs and big throttle tricks, so I think 1700kv would be perfect for me.

What kV motors were you running with 6s. If they were designed for 4s then I would suspect that is the problem. I know betaflight has that scaling to make it possible to run 6s on 4s motors, but I suspect it's not the same thing as having motors made for 6s. Never tried it(motor scaling) myself though.

From what I have seen.. you can scale motors DOWN, but you can’t scale them UP…
So you CAN actually scale your 1850kv motor to “fly” as 1700kv motors .. you just need to do the scaling in betaflight and a little math…
I have 2300kv motors and wanted them to fly like 1700kv motors.. so I divided one into the other, then X 100 and it gave me the % for the scale for Betaflight.. you also have to set up other stuff so the fc knows if it’s a 4s or 6s lipo.. you only have to do it once and it then does. It automatically..
You don’t have to do that, but you could just set up one profile for your “normal” 100% 1850kv. Then another profile with the % (dropped) to the 1700kv…
You will be able to “try” it just by changing profiles opposed to buying new motors…
I did hear there is a LITTLE efficiently lost when doing this from 4s to 6s… not sure if it will effect if ur just changing % for the same voltage…
Ciottifpv is constantly staring “run the highest KV motor you can, and just scale it down…”

I'll have to try that to see what the quad might feel like on lower kv motors.