Better iPhone 7 Battery Life
It would be magical if the iPhone 7 battery life is good enough to never need a battery case on hand to make it through a busy day. The iPhone 6s battery life is the biggest complaint I have with the iPhone 6s. The iPhone 6s Plus' larger battery is big enough but the smaller iPhone simply doesn't last long enough.
All signs point to an iPhone 7 with a new design that is thinner, cutting out a headphone jack to enable a slimmer device. It's not clear what will happen to the battery if Apple goes this route. removing the headphone jack and optimizing the components may allow for a similar or slightly larger battery, and efficiency upgrades could help make battery life better.
The biggest evidence that this will not happen is that Apple now sells an iPhone 6s battery case that fixes one of our complaints. We could see Apple go this route for the iPhone 7.
We are hearing that the iPhone 7 Plus may feature a much bigger battery, but the battery size doesn't have everything to do with the battery life you see in the real world.