After changing battery to 3s, drone does not fly

Dear Community,

Please help to understand whats happened with my pixhawk F450 drone.
I changed the battery from 2s to 3s and done ESC calibration. And my drone does not fly.
When I give trottle, it just turns to right side and props are broken.
I tried to debug the logs, but the waves looks fine.
Please see the flight logs:
2020-04-26 17-06-44.bin (420.2 KB)

This is my drone set:

What :scream::scream::scream::scream::scream::scream::scream::scream:. Are you flying on 2s battery with this motor :dizzy_face::dizzy_face::dizzy_face::dizzy_face:

Happy flying :face_with_head_bandage:

Good day, if you are using Simon k esc, they are not fully compatible with ardupilot., check also the correct rotation of the motors… cww and cw

Hmm firstly say I’m beginner in reading flight log but I’m still trying to find out.

When your copter is armed on nearly 7:37:11then voltage drop is too higher (maybe c rating is low) and apms draw is not higher then nearly 7:37:4 but when I saw motor out

7:37:11 motor 1 and 4 is running on highest pwm signal but current draw is not much at 7:37:4 also 7:37:11 voltage drop is higher but not current.

I think motor 1 or ESC is die (may-be :thinking: also 4th motor or ESC)

This is a current draw graph

Happy flying :slightly_smiling_face:

Can you pls tell me how you have set the rotation and order of the motors?

Thank you soo much for the help!

@Dave84 the seller of ESCs said they should support 3s battery. For setting the rotation and order of motors,props I used the previous setup with 2s battery. With 2s battery drone was flying.
This is the setup: pg.6

@Moksh I can run motors test, to check if motors are okay. But the motors are new, I think they should be fine.


What kind of escs and A ?

Why voltage drop is too high? And it is fine that voltage drop is high, when you plot the Bat>Curr you will see that it sinks lots of current.
Regarding to RCOU, so FC detects the C1 and C4 does not meet the pwm, so its sends signal them to increase rpm. But it does not mean that montor is dead, I think.

Dear Dave,

30A SimonK firmware Brushless ESC.

ESC Specs:
Cont. current: 30A
Max. current: 35A
Input Voltage: 2-4S lipo / 4-12 cell Ni-MH/Ni-Cd
BEC: 5V 2A (Linear mode)
Size: 55x26x8mm (length 145mm including power cable)
Weight: ~24g

Do you have set up you battery monitor ?

I think no, but battery is new I tested it on other devices.

battery monitor must be always set up…also if you change battery type, thats why better have few battery packs having the same voltage and mAh.
battery monitor must be always set up even the battery.s new., the sensor on the pdb monitor the consumption and drain of the battery and when the battery is low you can engage the RTL or Land., you can set it in MP and it will do in automatically or when you hear a buzzer tone mean its time to rtl or land.

Simonk firmware is not compatible with ardupilot… better bheli firmware with OneShot125

Dear Dave,

Thanks for your time.

If some issue with the battery we can always see it by debugging the log waves. So when i view the flight log, I do not see that there is any issue with the battery.
The latest flysky X6 is tracking the battery voltage, i am using it.

Simonk firmware is not compatible with ardupilot… better bheli firmware with OneShot125
Can you please little bit explain more here. Why simonk is not compatible with arudpilot?
I saw many people use simonk with pixhawk, no??

Its my suggestion to setup correctly all the sensors.

Thanks much!!
just last note, you recommended OneShot125, have you tired them? are they good ones for pixhawk?

me on my drones im using now the dshot protocol, I’ve used oneshot 125 for more 2 years of flight time without any issues.

aha, okay.
And what ESC support dshot? i will also use dshot.

Yes he is right because this dji ESC only support 3 and 4s lipo

How it’s possible :scream::scream: , firstly ESC are not capable also 2s in 920kv motor is not getting enough trust

Yes and also this is a dji motor (standard company also standard stuff)

Yes it’s probably true but @Hayk_Petrosyan are sure with your all motor rotating as sawing in @Dave84 IMG ???

Yes , simonK ESC made for plan :thinking: and pick any ESC on blheli fw it’s getting smooth experience.

Ohhh come on you pick up anyyyy blheli fw ESC it’s working on any pixhawk

Yes I also used oneshot 125 , dshot 150 , 300 , 600 it’s good

Happy flying :slightly_smiling_face:

Hi Moksh,

I know this is a bit of topic for this post, but I’ve noticed the graphs you’ve shown. What application are you using to visualize them? Is it an app? Of all the possible applications for analyzing logs that exist I don’t think I’ve ever seen that one.


This is a android app develop by @hosein_gh
It’s very nice and clean to find anything else on log data :sunglasses:

It’s helpful you :yum:

Happy flying :slightly_smiling_face: