Hi
Occasionally I take off and realise for whatever reason, be it a unforseen ground development, or just a change of nd filter, that I need to land, sort the issue and continue.  At what point with a battery level is it unsafe to re-take off.  I'm referring to levels of say 50%-70%.  Our UK course recommended that we don't take off at anything under 90% charge, referring to a new flight, but are there techincal reasons why we shouldn't take off again when level is 50%-70%?
If anyone can shed some tech on this.
Thanks
Ian  

"Our UK course recommended that we don't take off at anything under 90% charge"

I don´t get the purpose of this ...  
It surely must be based on how many minutes you plan to fly on your battery!?

DJI says to charge your batteries before every flight ... but if you land on a battery with 50-70% and do some adjustments ... this is (IMO) not what DJI refers to.

I would "re-take off" on a 40-50% battery if I´m just playing around ... If I where to get some serious footage I would change the battery for practical reasons!  

I agree with w1der... Also, I think we are getting confused a little.... if you are already fling and you land having 50% battery left and you want to take off again, by all means do so... you know where your batteries at. On the other hand if you are starting out for the day and you haven't flown at all and your battery is not at 100% or below 90% or even at 50% you are playing with fire, because you really don't know how much juice it has, because its been sitting. Then your best bet and safest would be to top it off before flying.

The OP is referring to the sudden battery drop syndrome and it's a valid concern.

The OP is referring to the sudden battery drop syndrome and it's a valid concern.

Thanks Jim, exactly my concerns about power drop.  Fairly new to RC, Inspire for 8 months. Maybe it's ok, but always good to hear other users experiences. It has always been back of my mind on re-take off.
Cheers Ian

I have understood that if you battery i fully charge on the first takeoff its ok to make several flights on the same battery. The sudden drop syndrome occurs when you fly a battery and wait a few days and then fly it again without charging - this is how I have understand it. It would have been nice to hear someone from DJI comment of this.

I have flown batteries to 50% drove a mile or 2 down the road and fly it again. I will say that I did not turn off the Inspire though. I have been shooting a lot a large ranches and although I have 5 batteries, iin some instances I can go through these pretty fast if I am not careful. I can not afford to to use one battery for each flight on large ranches. I would need 9-10 batteries. Not going to happen.

Many thanks,
Houston