P3A tried to autoland with a battery critical warning.

[peter west nz]

Now the good news - I was out over water and managed to fly it safely back and land on the beach - It didn't even get sand on it! The battery was an older one, but it still had 96% in it afterwards! The warning only went away after I restarted the battery. I was flying quite quickly and ascending. I did get the warning about propulsion being limited, to protect the battery, but that is quite normal and I backed off a bit on the throttle. The critical level was set at 10%
All the cells were within 0.1 v afterwards, and I didn't get any 30% warning Any bright ideas?

 

[GrammatonxXXxCleric]

My dad lost his P3A with 48% remaining. It auto landed on top of a 100 foot connifer tree. Took $200 and a professional tree climber to get it back. I still don't know why it auto landed with that much still in the battery. Could it be possible the last firmware update that included power management is the culprit??

 

[peter west nz]

Hard to say. It's the first time I have had it happen. I Had already flown 2 batteries, so it can't really be firmware in the bird, but maybe in the battery? Just remember that it will still let you fly it if it happens, even though it is trying to descend.

 

[Noodle]

Did you take off with full or near full (>95%) battery AND did not stop after a short flight and then took off again?

 

[lonjsnyder]

Now the good news - I was out over water and managed to fly it safely back and land on the beach - It didn't even get sand on it! The battery was an older one, but it still had 96% in it afterwards! The warning only went away after I restarted the battery. I was flying quite quickly and ascending. I did get the warning about propulsion being limited, to protect the battery, but that is quite normal and I backed off a bit on the throttle. The critical level was set at 10%
All the cells were within 0.1 v afterwards, and I didn't get any 30% warning Any bright ideas?

It's my understanding that, if & only if you treat your battery correctly, a DJI battery expected life span is a maximum of 80 charges. Mistreated batteries left in hot cars or fully charged for extended time periods will have a shorter life span. Batteries should be numbered and their usage carefully tracked. Also I good idea to use "AirDataUAV" fna "HealthyDrones" to log & track a battery's individual cell performance.

 

[peter west nz]

No, I took off with 100% battery and the "landing" warning appeared about 500m away. I was going to do another long flight over the local islands. It started to descend, and I flew it like a plane fpv to the beach, about 200 m away from me, and out of sight. I let it finish the autoland there. I didn't have goggles, so it's a bit of a mission, doing it with my S6 on a bright day.
This pic is as I found it. I knew it was ok because I still had fpv. I was flying from below the first lamp post at the top of the pic, and they are tall lamps. This battery has had 63 charges, and always looked after. It's no 2 of 5.

 

[HWCM]

It's my understanding that, if & only if you treat your battery correctly, a DJI battery expected life span is a maximum of 80 charges. Mistreated batteries left in hot cars or fully charged for extended time periods will have a shorter life span. Batteries should be numbered and their usage carefully tracked. Also I good idea to use "AirDataUAV" fna "HealthyDrones" to log & track a battery's individual cell performance.

This is very specific and very hard to believe.

 

[With The Birds]

It's my understanding that, if & only if you treat your battery correctly, a DJI battery expected life span is a maximum of 80 charges. Mistreated batteries left in hot cars or fully charged for extended time periods will have a shorter life span. Batteries should be numbered and their usage carefully tracked. Also I good idea to use "AirDataUAV" fna "HealthyDrones" to log & track a battery's individual cell performance.

It's well over 80 full cycles so way in excess of sticking it on the charger 80 times. I have batteries with significantly more than 80 cycles and all still perform well, capacity being close to new with no significant cell balance issues.

 

[peter west nz]

Yip, reported capacity was near 4300mah, from what I remember

 

[msinger]

Did you take a look at your flight log? You can upload and view it online here. If you'd like us to comment on it, please post a link back here after you upload it.

 

[peter west nz]

Here you go - I hope.

 

[lonjsnyder]

Looks like a warn out battery to me?

 

[lonjsnyder]

And this may be of interest:
HOW TO: Monitor battery voltage to watch for signs of failure

 

[peter west nz]

Yep, it doesn't look too good for it. On a different note, does anybody know if there is a way to prevent these batteries from timing out? I have a use for them in other portable equipment.

 

[lonjsnyder]

p.s. Have you ever deep cycled that battery?

 

[peter west nz]

No, never

 

[With The Birds]

Looks like a warn out battery to me?

Certainly a pack seemingly not suitable for future use. As to "worn out" it's just as if not more likely the condition might be attributed to a cell manufacturing defect or poor handling. This is not typical performance.

 

[Numone]

No, never

Worth a try. After-all, you've nothing to lose.

 

[peter west nz]

Very true - I might just do it over land though!

 

[peter west nz]

Here you go - same battery, not recharged - lasted about 1 min in the hover.