I have 3 and the charging station... It normally charges each battery 2x... So, I’ll start with everything fully charged and after I swap it takes about 15-20 minutes to charge a dead battery... So I have around 2hrs of flight time...
I found some at a local Apple store, if you happen to live near one it’s kinda nice. I’ve also heard of certain electronic stores selling them like Best Buy. If you need it today that’s always an option.
I flew my spark over 760ft straight up(I was in the middle of nowhere and no flight paths overhead)... But you should never do that unless you are taking pictures of a 400ft tall building and make sure that your not violating any airspace...