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Is it possible to disable battery failsafe in flight?

Hi,
I fly my quadcopter using Ardupilot software. The battery is 4cell LIPO (16.8V). As per your (the professionals) instructions I have set RTL when battery drops to 14.6V and LAND immeditately if battery level drops to 13.6V.

I plan my auto missions meticulously and what happens to me the RTL at 14.6V triggers when I am literally just 150m away already on my way home. I would rather my quadcopter finish its mission and not resort to failsafe.

Therefore, is it possible to turn off and/or modify the battery failsafe settings while in flight? Is it possible in QGroundControl to say, for sample: “after WAYPOINT #26 please disregard the battery failsafe”?

Thanks in advance!

In a word, no. But supply a .bin log file and let’s check out what is going on.
These are the battery related settings you were looking for:
BATT_ARM_VOLT,14.7
BATT_CRT_VOLT,14
BATT_LOW_VOLT,14.4
MOT_BAT_VOLT_MAX,16.8
MOT_BAT_VOLT_MIN,13.2

EDIT: just wanted to add that if you need to alter those params then either your battery is faulty and needs throwing away, or the voltage/current sensor is not calibrated correctly. Either way it’s a bad idea to alter those values - we’ve all been there and learnt the hard way.

Good day, im agree with shawn, never disable the battery failsafe also bcoz if you set the RTL related to the battery you can crash the drone.
Never change a the parameters during the flight… its not only dangerous but can cause injuries.

Thank you guys! I agree with you - safety first and we should not modify anything during the flight. Here I am attaching a graph showing what happened.

Blue is battery voltage, orange is current, and green is altitude for illustration. RTL is triggered when battery level is below 14.7V for ten seconds. As you see, there was a spike in current due to high winds. But soon after the RTL was triggered the voltage raised well above the 14.7V. So I guess this was just an unfortunate situation I have to deal with from time to time.

On a side note. Have you noticed the altitude gain/loss does not correlate with the current? I guess the quadcopter consumes about the same energy regardless whether it is climbing, descending or cruising. Is my observation correct?

Did you set the correct params for your pdb?

I havent done anything special. I have pixhawk black cube and I am using the standard power brick that comes with it. Did I have to set up anything there?

Post a link to the .bin log file. Dropbox or similar…

power module but be set correctly… you must set all the values needed with the values corresponding to the batter measurement you are using

https://ardupilot.org/copter/docs/common-powermodule-landingpage.html

@xfacta I really apologize I cannot find the log from the given flight. However, I do have another one that I did today. I flew the quad in loiter mode up and down (not really flying anywhere) it was a bit windy (10-14km/h winds) and the quad was going side to side - it did not look stable at all.

log is here:
https://drive.google.com/file/d/1eoJjr_mXFbU3_IYboljFfsdrEtfiB1kj/view?usp=sharing
Can you tell me what might be wrong please?

One information to disclose. The quad recently flew through heavy rain. I talk about it in this topic: Flew in heavy rain. Possible hidden damage?

Otherwise, I flew the quad in strong winds before and it behaved much better in my opinion.

I think you still need to set these values then find out why you battery voltage is not so good - either a poor battery or poor connectors.
Otherwise it actually looks OK and you just need to run Autotune.

If you want to try improving the tune a little before running Autotune, you could try these but watch for oscillations or radical behaviour. Start in Stabilise mode.
ATC_RAT_RLL_P,0.12
ATC_RAT_RLL_I,0.12
ATC_RAT_RLL_D,0.004
ATC_RAT_PIT_P,0.12
ATC_RAT_PIT_I,0.12
ATC_RAT_PIT_D,0.004
ATC_ANG_RLL_P,5.5
ATC_ANG_PIT_P,5.5

@xfacta many thanks for reviewing it! I will do and try as you suggest.

Anyways, when you say “it looks okay” do you mean all the VIBEs and IMUs are within the norm?

I am waiting for the weather to improve and I will run tests.

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