Originally Posted by John_V

Battery life when using any phone for a bike computer is pretty much a moot point if it lasts throughout your ride. I use an iPhone 5c with a Whaoo RFLKT+ and HR and speed/cadence sensors connected. I can do a century without recharging the battery and still have enough battery life left to make more phone calls than I need to. Since I recharge my phone every night, whether I ride or not, I always have a 100% charge in the mornings for my ride. Phones and battery life have come a long way over the years since they were first used for cyclometers and this was actually a problem.

You also stand a better chance of not damaging your phone if it's on a good handlebar or stem mount than you do if it's in your jersey pocket. In most falls, riders land on their sides or their back. The chances of you landing on your phone or the phone getting thrown out of your jersey pocket are greater than when secured on the handlebars or stem, since these areas seldom make contact with the ground.