Flying with a less than fully charged battery can cause this
- Thread starter GrammatonxXXxCleric
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i know 200 dollars is worth it to get your drone back.but was there no way youd attempt it yourself?or have you a crazy friend that would do it for you?
glad it all worked out.
glad it all worked out.
I discovered something that may be of interest. I tried to duplicate the problem of auto land. I first flew a battery down to 35%. Then I turned the drone off. Then turned it back on and hovered at 10ft or so. Within 15 seconds it squawked about low battery and tried to auto land. Even though the battery said 32%. I cancelled it and continued to hover till it needed to land. This tells me that when the battery level calculation curve is broken by powering down the Phantom will land even though the battery level is still above critical levels. If the drone is flown through the battery %'s it can project remaining time, but if the drone is turned off then continued flight with a less than full battery it will error on the safe side and try to end it's flight.
I know this, but my Dad did not. Easier to say than do when drone is trying to land in tree tops, blaring warning buzzers and lights flashing.... But the bottom line is (read the thread) is the drone went critical @ 48%..... Battery health was not the problem , DJI's wonderful "Safeguards" was.
As a long time TV cameraman and maker of videos I would have loved to hear a short interview with the climber, otherwise great video.
My guess upon reading through the thread is that "critical" battery levels did not force an auto-land, but that a brief "low battery" condition triggered "Return to Home" - and the drone was within 25' of its home point already - so decided to land in place (as described in the docs) instead of ascending and returning to the exact take off spot before landing.
The above theory is not meant to take away from the advice to fly with fully charged batteries - but AFAIK, that advice originated here on the forums and has never been confirmed by DJI (unless that has changed recently). They have a passing statement that says "you SHOULD always fly with a fully charged battery" - but nothing that says you MUST - and no cautions about unpredictable behavior if you do choose to fly with a partially depleted battery.
So - if this drone is still under warranty - and if in fact, the drone did go into auto-land at 48%, I would think you would have a pretty good case against DJI for any repairs that might be necessary due to this incident (but unfortunately no reimbursement for getting it out of the tree).
If anyone that reads this can produce a DJI document that says taking off with less than a fully charged battery voids warranty, or even one that strongly advises against it - please share.
I don't want the point of this thread to be missed on thinking that just putting a less than 100% battery in causes a RTH or auto-lose your $800. The drone the thread was started about was over 250ft from Home point. Auto land was initiated due to flying with a partially discharged battery AFTER having turned drone off and turning it back on. This indicates DJI software cannot account for discharge curve if drone has been turned off OR battery has been in discharge state. I duplicated this condition by partially discharging battery then starting flight after turning drone off. The identical action occurring showed what can happen. Flying the drone without turning it off seems to not have the same outcome. Battery percentage in this case has nothing to do with how long you can stay aloft, It seems that just by turning it off, then starting a subsequent flight ( Less than 100% not previously flown may not exhibit the same results) can trigger a less than desirable end game.
Sure. Like I said - "Return to home" was a guess. Thanks for clarifying.
But the conclusions you suggest are also far from absolute. They're certainly reasonable theories - but the root cause could also be something completely different. And if it is a "DJI software issue" - then the experience could be different from one firmware to another. Are you suggesting that the problem is in the battery firmware, the drone firmware or the RC firmware?
I'd be really interested in hearing an @msinger analysis of the logs to see why the drone thought it should initiate an auto-land at 48%. Have you been able to upload them yet?
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Is that an airfield above your photo where the autoland was started? Maybe that caused it to autoland?
This happened to me the other day, it gave me no option to cancel the landing and I also set off on a depleted battery, maybe around 40%. Its a good job I was just hovering over head otherwise I'd have been screwed. It happened the other day too when I was testing my new drone out in my garden. Scary stuff, makes me scared now to fly them out at distance.
Clicking the red cross did nothing, it wasn't a normal return home, the drone just drops out of the sky where ever this occurs.
You should be able to press the CONTROLLER RTH button to cancel. Then keep left stick forward as you plan a landing spot maneuvering with the right stick.
Thanks for showing me this...While the Mah (capacity) is showing about 25% remaining (percentage shown in the app) the voltage you have remaining (3.4V per cell) is less then 10% remaining probably closer to 5% or less...Something def. got out of wack...
This is written in the FW
"typeID" : 1,
"size" : 2,
"attribute" : 11,
"minValue" : 6900,
"maxValue" : 26000,
"defaultValue" : 14240,
"name" : "g_config.voltage.level_2_protect_0",
"modify" : true
The value is at 14.24V total pack voltage which works out to 3.56V per cell...
This is also written in the FW.
"typeID" : 0,
"size" : 1,
"attribute" : 11,
"minValue" : 0,
"maxValue" : 100,
"defaultValue" : 10,
"name" : "g_config.voltage2.level2_smart_battert_land_0",
"modify" : true
I believe this is the 10% Mah (capacity) remaining you see on the app...
When one of these happen it may start to land...So i would pay attention to both...
I think its important to choose the option in the app to show the voltage on the main
screen and use it like a tool as much as you use the percent gauge..When you are close
to 3.65V average Volts per cell you should be close to, if not at home point...
Also another thing to pay attention to is that the Voltage drops a lot faster the lower it is..
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I sure don't understand all this battery stuff about discharge every 20 flights....intelligent batteries...etc. I have a P3S....been flying it for a year.....no problems at all. Fly every day...at least every other day....only discharging the two batteries I have get is when I get the low battery warning. I land and charge the battery back up. It always starts a flight at 96%. In flight I always get about an 18 to 20 minute flight. I would guess that I have about 50 to 100 flight hours on these batteries. Maybe it is time for me to invest in couple new batteries but Im well pleased with the service I've got out of these batteries.
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