iPhone 6: 2 day battery life?

When Android screen sizes really started to balloon in 2011/2012, a number of commentators suggested that part of the driver was a need to accommodate larger batteries, to offset the power draw of early, relatively inefficient, LTE chipsets. Whether or not this is an accurate attribution of motivations, it is obviously true that larger phones can accommodate larger battery capacities.

Looking, then, at the much-prophesised bigger screen iPhone 6: I couldn’t help but wonder whether the need to increase the iPhone’s chassis would also present a good opportunity to boost battery life to a marketable degree. I know I’m far from alone at feeling the frustratingly slow progress of battery technology, and long for the days when I can last several days without needing to charge. Could the larger screen iPhone help move us a step closer towards that nirvana?!

So I decided to do some hypothesising about how battery life might be impacted by changing the screen size (and thus general proportions) of the next iPhone. I will say up front that I know how crude this exercise is - there are a considerable number of assumptions and extrapolations required to speculate on something like this. Nevertheless, I hope this makes for an interesting thought experiment, and may give a sense of where things might be going. Let’s start by recapping the dimensions of the iPhone 5/5s:

  • Height: 4.87 inches (123.8 mm)
  • Width: 2.31 inches (58.6 mm)
  • Depth: 0.30 inch (7.6 mm)
  • Cubic volume 55.14cm³

The size of the iPhone 6 will largely be driven by the display size Apple moves to. All the rumours and controlled leaks seem to be coalescing around a screen size of approximately 4.7" to 5", so I’m going to work on an assumption that the screen will be around 4.8"*. How would this translate to the overall dimensions of the iPhone 6?

Well, one has to assume that Apple wants to keep the phone as compact as possible, and will try to adapt for the screen by shrinking the bezel as much as possible. But they can only go so far. The "chin" will still need to accommodate the TouchID home button; and (barring a radical and improbably relocation of components) the top is likely to still house the earpiece, sensor array, front camera. etc. Providing space for these, whilst shrinking them down to an achievable minimum, indicates that the iPhone 6 would realistically need to be approximately 0.8" taller overall than the display (0.5" below the screen, and 0.3" at the top). The width, of course, need only be very marginally more than that of the screen.

One can hypothesise, therefore, that an iPhone with a 4.8" screen could have the following approximate dimensions (and if anyone has the Photoshop skills to mock up something with these proportions, I'd love to see it!):

  • Height: 5 inches (127 mm)
  • Width: 2.45 inches (62.2 mm)
  • Depth: 0.30 inch (7.6 mm) (unchanged)
  • Cubic volume: 60.04cm³

This would result in a very modest increase in the overall dimensions, and yet the volumetric increase is still respectable at approximately 5cm³. Doesn’t sound like much, does it? But the volume of the 5s battery is barely 10cm³ anyway. Assuming, therefore, that Apple can devote all of the extra volume to battery (not unreasonable, bearing in mind that the iPhone’s components invariably shrink year on year…) that would mean approximately a 50% increase in battery capacity – from 1,570mAh in the 5s to 2,355mAh (which is, perhaps unsurprisingly, broadly in line with the capacity of batteries on the Android phones of equivalent size…).

Continuing evolutionary efficiencies in other areas are also likely to help the cause: through software, to die shrinking, improved radio performance, and superior screen technology such as the hyperbolically-named(!) Quantum Dots tech used in the Kindle Fire HDX 7. Taken as a whole, it may not be at all unrealistic to aim for 60%-75% real world improvement in battery endurance over the iPhone 5s. Which should be enough for Apple’s marketing team to brand the iPhone 6 as having "2 day battery life".

What do you think? Whether or not you think the numbers hypothesised above stack up, do you think Apple will look to make significant improvements to battery life in the iPhone 6? Will it do this even if it means stalling its almost OCD tendency to make its iPhones as razor slim as possible? I, for one, am hoping that the iPhone 6 is not any slimmer than the already-svelte iPhone 5/5s – keep the depth, and use it to pump up the battery!