"Critical battery" warning issues

QuadGrandad · Feb 28, 2015

(I can't find this issue on the forum. Sorry if its a duplicate)

I had 39% battery before take-off, flew for two minutes in backyard and got a 'critical" warning, and the quad started landing.... Fast. I was only up about 20 ft, and by pushing up on the stick, I was able to land softly. Took quad inside, turned it back on, and battery reset to 35%. Temp outside was 39-40 degrees.
Is this a common experience? If I had been a few hundred feet in the air, I believe I'd have taken pieces back to the house.

sirebral · Feb 28, 2015

39% is pushing the limits for what I'd feel safe starting a flight. I usually end my flights @ 30% as a precautionary measure.

Paul K · Feb 28, 2015

I don't have experience with Inspire batteries (yet) , but I thing it will have the same issue as phantom ones .
If you fly the battery previously and you might have 95% left ,and reinsert and try to fly again , you will have the same behaviour as yours 39%.
It is not the battery issue ,but it's electronics. The biggest issue is ,if you have more than 90% battery power left ,the charger will not engage .
In this case I always let the craft hover below 12 V ,to be able recharge the battery before using it again.
Do your test ; insert recently charged battery ,fly it for few minutes ,remove it from the craft ,reinsert hover it in safe distance and watch closely battery telemetry to see how fast the power is dropping.
I would suggest to fly only on freshly charged battery.

Kilrah · Mar 1, 2015

You might need to calibrate the battery as per the instructions. And you'd want to look at the detailed battery info page when you see that issue to see what the reason is.

The Editor · Mar 1, 2015

Paul K said:
........The biggest issue is ,if you have more than 90% battery power left ,the charger will not engage ....

Yes it will - On the Inspire you just need to switch the battery on first before you connect it to the charger, then it will start to charge even if the initial state of charge is over 95% !

Mossie · Mar 4, 2015

I've just had the fright of my life with the same problem. Thank God I wasn't over water, my hand is still shaking because I thought I'd lost it.

I charged up a new battery I'd bought. Being impatient I went flying before it was fully charged. On the app it said 85% . I had a few transmission problems with very choppy and stuttering video, so I brought it to the hover whilst I messed around changing from Auto to Manual channel selection.
Next thing I got the audio warning " Landing gear lowering" and then to my horror I saw 'Critical Battery'.
I didn't want it to land where it was, so I managed to get it to the same field I was in. It landed with 0% battery power showing !!!
So the battery went from 86% to Critical, bypassing the 30% Low battery warning

Anybody any ideas what I might have done wrong ? I've just done the latest firmware update, but this battery wasn't in the aircraft when the update was done.

Kilrah · Mar 4, 2015

Once again - looking at the battery details page would have probably given you he answer. As it is you can look at the battery log to see if any errors are reported and calibrate the battery as described in the manual and hope it gets better.

Mossie · Mar 4, 2015

thanks for the reply.

I see in the manual that there is a warning that you must charge the battery fully before first flight. My fault for not seeing this warning and maybe this caused the problem. Maybe not.

How do you calibrate the battery, I can't find this in the manual ?

Mazz · Mar 4, 2015

39%?? you are an adventurous person.

sirnikolas · Mar 5, 2015

I won't go flying unless all my batteries and RC are 100% charged. I wouldn't want it to fall on anyone or anything. Plus last but not least,
it's a lot of coin to lose :/

DCGOO · Mar 6, 2015

Mossie said:
Anybody any ideas what I might have done wrong ? I've just done the latest firmware update, but this battery wasn't in the aircraft when the update was done.

Yup, You left on a long trip without a full tank of gas.

VAP · Mar 31, 2015

I personally cannot stand the auto land features forcing the aircraft to land when you may not want it to. IE over a house or tree. I can see the power remaining and will land it when I want, not when the computer thinks it should. How dumb do they think we are. It almost crashed because I was battling with the auto land feature pushing up when the craft was only 10 m away from me! It is like a flying a Cessna and when your at 25% fuel, it automatically reduces the throttle to bring you down. It is just unsafe navigation to operate that way. Experienced pilots should be able to turn the feature off or to 5%. It is the same with RTH when battery is low... I do not need that feature.

The Editor · Apr 1, 2015

VAP said:
I personally cannot stand the auto land features forcing the aircraft to land when you may not want it to. IE over a house or tree. I can see the power remaining and will land it when I want, not when the computer thinks it should. How dumb do they think we are. It almost crashed because I was battling with the auto land feature pushing up when the craft was only 10 m away from me! It is like a flying a Cessna and when your at 25% fuel, it automatically reduces the throttle to bring you down. It is just unsafe navigation to operate that way. Experienced pilots should be able to turn the feature off or to 5%. It is the same with RTH when battery is low... I do not need that feature.

Just set critical to 10%...... Boils down to pretty much the same thing. Anyone flying their Inspire regularly to 10% battery is dicing with destruction in any case. Lipos taken that low in their discharge curve can drop like a stone taking the craft to LVC in any case. (Or the batteries own LVC).
If you are so far from home at approaching 20% that RTH kicks in you shouldn't be owning an Inspire!
The lowest I have ever flown any of my packs is 18%.

m00se · Apr 1, 2015

I would never take off without 100 % charge unless I know its a small test hop and I have almost no wind.

taking off with 39% is suicide,

m1ch1gan · Apr 2, 2015

The Editor said it well. Lipos are diff than other battery types. I always plan on having my Inspire landed at 30%. It's just good safe flying practices. Besides, I have too much $$$ into it to take those kind of chances.

Blurfonz · Apr 4, 2015

Guys this happened to me. I made this video, so as people will know. Even DJI should see this video! I could had potentially lost my Inspire1! The battery dropped from 74% to 8% in a second! The critical message displayed and the craft immediately landed itself straight down!! I could had been flying in the sea. It was definitely a very scary experience!

Pls do something DJI!

Sent from my iPad using Tapatalk

The Editor · Apr 4, 2015

Blurfonz said:
To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

Guys this happened to me. I made this video, so as people will know. Even DJI should see this video! I could had potentially lost my Inspire1! The battery dropped from 74% to 8% in a second! The critical message displayed and the craft immediately landed itself straight down!! I could had been flying in the sea. It was definitely a very scary experience!

Pls do something DJI!

Sent from my iPad using Tapatalk

What were your individual cell voltages?
How many charge/discharge cycles on this pack?
When was the last time this pack was calibrated?

Blurfonz · Apr 4, 2015

I am unable to charge the battery now, the 3rd LED blink twice , in that case it seems like it is over-charge detected.

I looks at the individual cells through the DJI app, the last cell is different
http://i292.photobucket.com/albums/...1-4CFC-B753-24C90F6894FF.png_zpsfnxrcw4o.jpeg

How do I discharge it?? I cannot start up the motor as the percentage is too low .... I left it powered on in Inspire for 5-6 hours, yet it does not goes flat. Its seems to take forever.

Please advise.

Sent from my iPad using Tapatalk

The Editor · Apr 5, 2015

Blurfonz said:
I am unable to charge the battery now, the 3rd LED blink twice , in that case it seems like it is over-charge detected.

I looks at the individual cells through the DJI app, the last cell is different
http://i292.photobucket.com/albums/...1-4CFC-B753-24C90F6894FF.png_zpsfnxrcw4o.jpeg

How do I discharge it?? I cannot start up the motor as the percentage is too low .... I left it powered on in Inspire for 5-6 hours, yet it does not goes flat. Its seems to take forever.

Please advise.

Sent from my iPad using Tapatalk

Wow, you have a serious imbalance on those cells and the Inspire/battery thinks it only has 114mAh left in it!
The pack only has 16 charges on it. What have you been flying the pack down to percentage wise?
Have you charged the pack fully EVERY time you have flown it or have you done any partial charges?
That looks like you need to return that pack to DJI.

Kilrah · Apr 5, 2015

Either there's really a bad cell or the monitoring circuit has gone bad (which would explain one cell being much too high and an adjacent one too low).
In any case that battery's dead/defective, don't use it and see about returning it or have it replaced.