Sony says you ought to get up to 880 hours of standby time and 110 hours of talk time, but those figures assume it's sitting there unused in a sock drawer for the time period.
In terms of actual meaningful use, I found the Z1 was easily good for a whole day of use and then some, with my review days including stacks of camera work, lots of tweeting and having the email app set to check for new messages every 30 minutes.
Sony's power-saving features don't amount to much more than turning everything off when the battery reaches a (user definable) level, but there are some useful power-saving tips that pop up in the Notifications field.
For example, the Xperia Z1 told me the Dropbox app was stopping the phone's Stamina energy-saving tool from deactivating Wi-Fi when the screen was turned off, which is a useful thing to know and might help to genuinely improve power management.
I found it possible to get through a day of heavy use, plus the standard TechRadar video file – a 90-minute clip played with the display at full brightness – reduced the Xperia Z1's battery from a 100% full charge to 81% remaining. It'd do you for even the longest commute.
Wireless connectivity is represented well in the Z1, with it supporting the new LTE or 4G bands, plus 3G HSDPA maxes out at a theoretical 42Mbps, should Three have positioned a phone mast at the end of your garden.
Sharing video is one of Sony's key boasts for the Z1, with it able to 'Throw' footage to other devices. In practice, this means going through the cumbersome process of discovering and pairing the Z1 with another device, a process so tedious that the moment will surely have passed before the video or image can be shared.
It also supports DLNA, which is a little easier to manage, plus screen mirroring through a select few devices that support Wi-Fi Direct connections.
Which are all lovely ideas, all pretty awkward in execution and unlikely to be used much.
And in an example of another area where Sony and Google's services overlap is in the phone location department. Heading to My Xperia lets you track your mobile, set its alarm off, lock it down and even perform a full remote erase, mirroring the features of Google's own Android Device Manager.
Sony really ought to have a meeting with Google before it makes the Xperia Z2. It'd save it an awful lot of effort.