Over the last couple of weeks i have had a few people ask me how the battery life is on the new iPhone 5S. At the time of this writing my phone's status is as follows. 40% Remaining, 4 hours 12 min Usage and 1 Day 12 Hours standby. This means that i haven't had to charge my phone all weekend long. It is also worth noting that i have not done anything to tweak the power settings such as turning off parallax effect or turning off background app updating.
I feel that the iPhone 5S is right on par with the same performance as the iPhone 5 when it comes to battery life unless you are using your iPhone 5S for certain tasks. If you are using your iPhone for things that are requiring access to your sensors such as an App that tracks running distance. These apps are using the new M7 Co-Processor and this will save on battery. The M7 is designed to keep track of you even when the phone is asleep giving rest to the iPhone's main processor the A7 and in turn saving your battery life.