Good for 3 to 4 flights of 35 minutes each on a full charge, depending upon the screen brightness setting. Almost any powerbank can charge the RC Pro during and between flights to increase that.
"with up to 3 hours of battery life, you'll effectively have four Mavic 3 Intelligent Flight Batteries worth of flight time with a single charge!"
I don’t often have an issue with my RC pro but a big problem with my old iPhone, especially in the cold. I keep it plugged into a external power pack so instead of a dead phone it stays fully charged. I imagine u can do the same with the RC Pro. I’m sure u can find a way to Velcro it to yr lanyard ( if u use one) or just stuff it in yr pocket.