Just a quick question as listed in the title. I have an iPhone 5s and have found it runs out of juice before my second Mavic battery. Today i noted that the phone was at 95% at the start of my planned 2 flights but my second flight was cut short when my phone popped up with the "low battery" message. Am i supposed to have the phone running in low power or flight mode? or is there something else im missing. I have no other problems with the phone battery and a charge over night is always enough to easily get me through the day. Im new to the mavic and have maybe been spoilt with my Phantom 4 controller charging whichever display i choose with that.
Many thanks for any thoughts.

iPhone 5s battery isnt going to last long. Id suggest to upgrade hones or get a iPad mini. Even tho your phone last you throughout the day, I bet thats with Minimal use, when you phone is running an app for a long period of time and also using cellular data for maps, ect. your battey will drain quickly. It also depends on screen brightness ect....

I use IP6S+ and i can fly between 3 and 4 batteries on average.

I kinda agree with the other replies.  The iphone 5+ isn't optimized for all the uses that DJI Go uses constantly.  GPS, video processing, interaction with the app, background apps etc... Unfortunately it's a semi weaker battery running 32bit OS.  The newer 64bit is smoother, especially with the bump in battery power on the 6(any model) or 7.  

You could try airplane mode while flying... that may give you a few extra minutes, but might be a negligible gain over time.  Also, might try upgrading to the 10.3.1 OS, but if you're jailbroken, don't do that.  

Many thanks for your replies. I have an iPad mini 2 which I use for my phantom 4 but wanted to use the phone for the mavic for space. Also, the iPad seems to lose video signal (green screen) on the phantom which the phone has never done. Will try it with the mavic though. Thanks again for your thoughts.