It took me about 3 months of flying to get to this point. How long did it take you?

It takes about 4 batteries to cover 100'000ft.   

Weather permitting and depending on frequency that you fly you can easily reach 100,000 feet quickly.  When I first got my Air 2S I flew over 100,000 feet in just 3 days.  I don't sync my flight data so the feet flown showing under my Avatar only reflect a test flight before I remembered to turn off data sync.  I store all my flight data on my local cloud.

I got there pretty quickly.