I was flying my p3p late Saturday afternoon - showing off for some friends.  I got a "Critical battery" error (I don't remember the exact wording). I was about 1100 feet out at 280 altitude.  Thinkng back I probably should have set the hompoint to the current drone position and started an auto landing sequence, however I elected to get it back home ASAP.  Thankfully I had no issues though the warning stayed on the whole time.

When I took a look at the drone I noticed there was about a 1/8 inch gap between the top of the battery and the aircraft itself.  Apparently I had not "clicked" in the battery fully.  In messing around with it I noticed it is failry easy to "not quite" get the battery in all the way.  You can bet I will be extra careful from now on. Be sure to be check your battery after you think it is securely installed.

One other thing, since the drone never fell from the sky obviously there was never a loss of power which means there is a sensor in the system somnewhere that checks the placement of the battery. I know there are a lot of deserved criticism of DJI here, but in this case I would like to thank their engineers for putting a "loose battery" check in the P3. It appears to have saved my careless butt!

Great post . I always wondered what would happen if you lost partial power from the battery .  Wish I never get a critical battery error .. Or anyone else ....

He didn't lose power from the battery, if he did his p3 would have fell out of the sky..  Only 2 things could cause a battery warning and that is 1 battery is low or 2 the sensor connections next to the battery connections were contacting or contacting properly

I don't mean to sound mean, but if you are having issues putting the battery in a p3 like you are you should sell it now before you hurt someone!

Mark97564 Posted at 2015-6-8 11:36
I don't mean to sound mean, but if you are having issues putting the battery in a p3 like you are yo ...

I made a mistake and admitted as much here publicly in hopes that others pay extra attention to the battery fit. I had not had this issue in the 30+ previous  flights I had made. I admit I can always be a better pilot. I'm guessing you will always be an a$$ however.

danno1 Posted at 2015-6-8 11:47
I made a mistake and admitted as much here publicly in hopes that others pay extra attention to th ...

Me thinks there should be a separate area in this form for super-pilots that don't suffer the frailties of us mere mortals.

I'm happy to hear that you managed to land the Phantom 3, good information, thanks!

ABSOLUTELY......even the best make mistakes.    To help others along their way and to learn, is a great forum thread.    Thanks for sharing.   At a minimum, it reminds us all that a preflight checklist is the way to go.   I know I forget the silliest things.....such as, pressing RECORD.   Thanks for sharing!   Mike

I lost a battery out of a p2v plus once from not seating properly. Dropped about 6 feet. It's easily done. No judgement. Glad it worked out.

People need to remember the old saying " If you have nothing nice to say , say nothing at all " , most of us a new to the hobby , so be gentle .....

Total Posted at 2015-6-9 11:04
People need to remember the old saying " If you have nothing nice to say , say nothing at all " , mo ...

I TOTALly agree with you.

"...which means there is a sensor in the system somnewhere that checks the placement of the battery..."

No it doesn't mean that at all.  I can see no sensor checking battery position.  It means that under flight conditions the aircraft wasn't getting what is needed from the battery and probably the battery was poorly connected.  If the battery is lose it might be fine on the ground but under vibration or G-force the connection might be poor.  A poor connection might increase the resistance which would reduce the power to the systems and increase heat at the contact.  My guess is that under the vibration of flight this is what happened.   Check the contacts are clean as well as there could be marks from the poor contact.

When I fit the battery I pull back to make sure it is seated.  Simple procedure. :-)

jon.godfrey Posted at 2015-6-9 20:25
"...which means there is a sensor in the system somnewhere that checks the placement of the battery. ...

If what you are saying is true and there was some form of power disruption that was detected wouldn't I have noticed SOME sort of issue with the craft itself? Other than the warning there were no other symptoms - control was fine, telemetry was fine, lightbridge was fine.

There are 2 sets of contacts on the battery, 1 set is power and the other set is communication, by not having the battery in all the way the power contacts were made but the communication contacts weren't, that is the only explanation why it didn't fall out of the sky and informed you of a battery condition besides the craft malfunctioning which I doubt because you said it wasn't in all the way and when you did push it in all the way things were fine

Mark97564 Posted at 2015-6-10 00:14
There are 2 sets of contacts on the battery, 1 set is power and the other set is communication, by n ...

Wow - very interesting.  Thanks for the info!

Np..  The communication contacts are how the p3 knows the things it shows you about the battery, like cell voltage, how many times it's been charged and so on...

Understood.  In playing back the log I noticed that at the time the error was reported the battery was at 54% and never changed after that.  This certainly seems to confirm your explanation.

The same thing happened to me today.  I had not plugged the battery in all the way either. I was about 500 feet out over water and was shaking as I brought her back. this could have been a total disaster if the batt had vibrated out further.

Well I really asked myself if I should write that, because I thought I'd be the idiot... but I made the same experience last weekend.

I got my 2nd battery last week and I was pretty sure I had inserted it correctly. Though I didn't remember if I heared that "click". After 5 minutes of flight (in gusty winds), I got the warining as well. Returned the Phantom quickly, fixed it and went on.

At least I will definitly listen for vibrations or the "click" in the future...

Sven

Update: My battery had loosened and come out app. 2mm.

danno1 Posted at 2015-6-9 22:32
If what you are saying is true and there was some form of power disruption that was detected wouldn ...

perhaps but perhaps not... my logic is when the battery isfull a poor connection is less of an issue.  As the battery runs downit becomes more critical until there is a system error.  DJI use a"belt and braces" approach to the connectors which are gold contactsand sprung.  I think this is as they have had connection issues indevelopment but look, this is an informed guess.  

Just another comment; low voltage DC can surprise you.  We nearly had afire in our house where a 12v DC connector was placed too close to a halogenlamp.  the connector plastic melted and the DC shorted out.  The PSUwas fine, pushed out just a few amps but this was enough to cause a flame.Lucky the system tripped and the smoke alarm alerted us.  The lesson is weshould respect the power of low voltage DC.

I push the battery in then try to pull it back withouttouching the two release buttons to make sure it’s secure.  I think this is a good safety check.