The Sony Xperia Z Ultra packs a 3,050 mAh capacity battery which is smaller than the one inside the Galaxy Mega 6.3 (3,200 mAh). You do still have some of the power management tools, specifically STAMINA mode to keep the Z Ultra going.
Sony claims you should get around 8 hours of life. In extreme conditions looping video the Z Ultra manages with maximum brightness around 5-6 hours but on general use manages around 7-8 hours. You will need to tap into that Stamina mode to get through a day’s use.
In terms of speed of charging, hooking up to the power adaptor for 30 minutes from a critical battery levels jumps up around 10 per cent. Battery quickly drops off simply going on Twitter or browsing the net, though. Streaming movies hits it harder and it’s here where the screen invariably saps the life out of the battery. It can make it through a day, but for more intensive tasks, you really need to keep an eye on what you are using during the day.
Sony Xperia Z Ultra - Call & Sound Quality
Once you get over the embarrassment of putting the tablet-looking phone next to your ear, Sony includes a host of features to ensure calls come out nice and clear. There’s active noise cancellation using a secondary mic and 'HD voice' also aims to reduce background noise and improve clarity.
The call-making experience is very similar to our experience with the Xperia Z where calls can sound a little distant. The HD voice technology does a good job drowning out exterior noise but can sound hollow and muted at times.
As for the internal speaker, we've already mentioned the issue of speaker placement
becoming a nuisance when watching video or browsing in landscape mode.
It’s a very tiny speaker. Sony’s ClearAudio and xLoud enhancement audio tech aim to improve clarity, and while dialogue is nice and clear it’s overall a tinny experience. it lacks the warmth and richness needed to make it ideal for watching films. Things improve when you plug in a pair of headphones.
Should I buy the Sony Xperia Z Ultra?
If you are truly sold on a phone this size, then the Z Ultra is the best 6-inch phone out there. It’s only real rival is the Samsung Galaxy Mega 6.3 (£449). The super-sized Galaxy S4 didn’t really make a good impression with its old specs and some performance issues.
The Xperia Z Ultra at £600 is more expensive SIM-free and does have the same size issues. It's just feel too big to comfortably use as a phone and is more suited to be used as a tablet. We do like the bright, colourful screen, the Z1-like performance and it has a far nicer design than the Mega. We were left disappointed by some of the features to take advantage of the larger screen estate notably the frustrating input support and decent but not Z1-quality camera.
You have to keep an eye on what you are using to make sure the battery makes it through the day as well. If you really have to go for a ‘big phone’ without the worry of fitting in your pocket, using it in one hand or getting the benefits of the larger screen, we’d opt for the Samsung Galaxy Note 3.
The Sony Xperia Z Ultra is a big phone with a big performance but it’s just too much to handle or keep in the pocket.