If you’re a mobile gamer, you know the bliss of playing anywhere you want to go — and the anxious downside of draining your phone’s battery as you do. That’s why the OnePlus 15‘s massive 7,300-mAh battery makes this a promising handset for the discerning gamer on the go. Presumably, you’ll be able to play for longer without draining your phone down to low capacity. The reality is a little more complicated, partially because the OnePlus 15’s advantages ca...