Fast Power Loss ??

[aburn09]

I have two identical 220 racing/freestyle quads the only difference between the two is one does have Emax red bottom motors which do use the batteries a little quicker than the other quad but barely noticeable and although my 6x 1400mah batteries are not new they still give me about 4 minutes of fly time........But i'm now getting major power losses from the quad with the emax motors so much so i'm only getting half the flying time at best before it looses power in the air according to the battery monitor osd in the left hand corner of the video and comes crashing down to earth.........it's always when I'm doing a power loop when obviously the battery is working at its hardest.....I've include 3 examples videos.
I know its definitely not a FC issue or a signal loss everything does point to power loss but then why does my camera keep recording ?
Ive had a bad battery before but when it  went below a certain voltage you got a snowy picture as the camera looses power too but that's not happening here ?.....Also as you can see are the end just before it crashes I get my osd stats suddenly come up on the screen as though I've disarmed the quad ?
When I check the batteries with my battery checker they show the have still got 50% charge left ????
I've also enclosed a screenshot from the blackbox recorder which up until the crashes don't show any problems either with motors or gyro ??

Any ideas/theories appreciated 

https://www.youtube.com/watch?v=laoF2XyV5c0
https://www.youtube.com/watch?v=9gHtHMBa1sI
https://www.youtube.com/watch?v=3L6ZzcpxX-0

[Tryingto]

I run the original emax redbottoms on 4s and I get a reasonable flight time out of them (4 and a half mins). What props are you using? I tried some bullnoses once and they really reduced my flight time. I run hq 4x3x3s now and its much better. What sort of batteries are you using (brand, reported c rating, age)? Do you storage charge them when your not using them? How heavy is the offending 220?

[ched]

From the videos it looks like it was disarmed mid air! It's probably not applicable but is your idle too low? Maybe the Red Tops bearings are getting worn and pulling more current so their idle speed drops too low to recover?
Can you see any failsafe events in the BlackBox logs?

[Cheredanine]

Not power. The flight controller disarms or failsafe. Osd switches to end of flight data immediatley. Power would cause reboot

Picture of bb log is largely useless, can you post the full log file or put it in drop box and link here?
(Will take a look later)

I notcce water on the cam lense, are you flying whilst raining? Is it possible there is water on the fc too?
Also please post a pic of the quad showing where the antenna are placed

[Two-Six]

I think your batteries are too cold when you flew or that they have been cold, you hammered them and damaged them or you charged them when they were cold.

LiPo's hate being the cold and I am sure it can trash your batteries....

[Cheredanine]

If the fc lost power it would be rebooting, not showing end of flight data on osd.

If the motors didn’t have enough juice. You would see all motors max on the bb as the fc shouts for more thrust

It isn’t power
Edit: in fact I am not convinced the bb screenshot is in the right place. Really would like to see he log its self

[aburn09]

Cheredanine I've tried to find a way of sending the bb data but it won't load on here or dropbox  .
Thanks to everyone else for your valid comments but like I said I've been using this quad for a year and a half with no problems the only thing that's changed is I've updated both quads to betaflight 3.2 the airmode minimum is set to 1070 which has always been set to that with no problems i'm using the same props, batteries as always so I can't see why the problem suddenly occurs on this quad ?
The receiver on the quad is not blinking which would confirm a signal loss.......So still none the wiser ?

[atomiclama]

I vaguely recall something in git similar to this. When the batt is determined to be to low the FC disarms, and some users reported that the batt filtering was wrong. 

But I maybe confused, it happens a lot recently  ::)

Could you try updating to a newer nightly build?

I'll see if I can find the stuff on git.

[Cheredanine]

The best I can tell from the video it is disarming in the air. (Bb would confirm and may give further indications, but proceeding on that line..)
There could be multiple reasons for this. If lama is right, then woot.
Are you using switch arm?
What is cpu load like?
Have you tried flashing back to an earlier release?

[aburn09]

Thanks for all the help maybe I need to reflash betaflight to before 3.2 as I didn't have the power losses before ? Just wondering why the osd battery voltage shows critical before the crash yet the battery checker shows 50% ?

[atomiclama]

Ok this is what I was thinking of

https://github.com/betaflight/betaflight/issues/4421

This guy's FC thought it had 5S instead of 4S lipo and so showed low volts very early on.

No disarm though, must have imagined that  :embarrassed

Could try his fix

Code Select Expand

vbat_max_cell_voltage = 42 to vbat_max_cell_voltage = 43

Are you running 3 or 4 S ?

Looking at the OSD it is reporting 11.6 on power up should be 12.6 so assuming 3S

There is a calibration page in the configurator where you can tweak the setting so that it shows the correct voltage.

When powered up on the bench read the lipo voltage with a meter and adjust the configurator settings until it matches.

Give that ago, no idea if it will help with the disarm though, worth a try.

[Cheredanine]

I remember reading that one now mate, but no, it isn’t the problem, that doesn’t disarm and look at the DVr, bf doesn’t force disarm because of low lipo, quite often pilots I fly with push the lipo too hard and it dies, but the fc generLly gays armed, if you keep going eventually it reboots

[aburn09]

I think Cheredanine's disarming comment is the nearest theory as to what's going on as the only way I can get all the osd stats to show on the screen as it shows in the videos just before it crashes is to disarm it using my tx switch.
All the videos are with different 3s batteries.......I do have one 4s battery which is almost new but I remember when I flew with it a couple of times I wasn't getting any longer flight times and this was before I had osd and both times as I was about to land at 4 minutes i got a snowy picture and the quad dropped to the ground luckily both times I was only a meter off the ground so no damage done but the quad alarm didn't give me any indication the battery was that low !!
I fly all my quads using my battery alarm on my quads and my timer on my tx which I set to 4 minutes so when I either hear my alarm going off or my timer on my tx beeps at 4 minutes i bring the quads in and all cells show roughly 3.8v so this has been a tried and tested method I've used for years.
Again getting back to the disarm theory all these crashes haven't broken any of the props which again would indicate all the motors have stopped spinning before the quads hits the ground........So what would cause a disarm if we are going down that line of thought ?

[Cheredanine]

See questions above mate.
(Eg are you using switch or stick to arm?)

[aburn09]

I arm and disarm using a two way toggle switch on my tx 

[Cheredanine]

Ok mate and others two? (Cpu load and have you tried flashing back to earlier release?)

[aburn09]

Interesting I just reflashed the quad from 3.2 back to 3.1.7 and just flew 3 batteries and not one problem ??? 
Not sure now whether I had a bad download of 3.2 in which case do i risk reflashing back and try again as I think there are a few newer versions on betaflight since I flashed to 3.2 a couple of weeks ago ? 

[Cheredanine]

They have been working on disarm and arm in relation to crash detection, it is possible it’s a code error.
I would post an issue on github in the section lama linked

[aburn09]

I've just reflashed back to the latest 3.2 version which is two days old and...............Flew four batteries with again no problems 
So not sure what the problem was but it seems to have gone !!
Thanks to everyone who tried to help  it was a head scratcher but hopefully it was a glitch in the original 3.2 I flashed to my board ?
But hopefully back now to a happy flyer...... although a cold one at the moment brrrrr 

[atomiclama]

Unless you flash to exactly the same version that you originally had problems with. Then there may have been code changes / bug fixes.

But glad it's sorted.