battery life with spark

Hi - new pilot (Christmas - 3 hrs flight time). All seems as expected - loving the #perspectives. Question: Do some flying activities use the battery faster? For example, does Sport drain faster, or does video drain faster? Just looking to maximize flight time. With two batteries ... just...

watching a youtube vid about spark and an interesting topic came up... The vlogger said 'film until about 15% battery life left then switch over to Sport Mode and return quicker than normal mode...' My Q is: doesn't Sport mode drain the battery quicker and thus cause an issue where the spark...

Anyone else seeing this? Couple of Spark flights and my iPhone 6 is pretty much sucked dry. Seems there are reports that older apps didn't do this with older iPhones. What's happening?