Flying faster, with more stunts, will exhaust the battery a bit faster
But your losing close to 10 min fly time? Do you ( CYCLE ) your batteries?
After every 5-8 flights, drain batteries all the way ( not going below 8% )
Then fully charge again, the batteries maintain ( MEMORY ), if you do not
Cycle your batteries, they will take LESS charge, each time you charge them,
Ultimately REDUCING battery power and life!
Also those batteries are only have a ( 1000 ) charge life, before they start to fail
And no longer hold full charge!
Try cycling first, if not hook to PC ASSISTANT, and check battery stats, they may be
Out of whack? If you fly close ( line of sight ) change your ( low volt warnings ) from
30% first alarm, and 20% critical alarm, to
25% first alarm, and 15% critical alarm, this may give you a few more minutes fly time!
Hope this helps!