iPhone 6: A Big Screen Is Nice, But The Bigger Battery Is Necessary

Apple fans have been looking over at the big, beautiful screens of Android phones like the Samsung Galaxy S5 for a long while now. And while the continued sales success of the iPhone shows many are satisfied with what they've got, there is little doubt many are salivating at the prospect that next month's iPhone 6 announcement will at last bring larger displays to Apple's flagship product. Indeed, rumors from the supply chain suggest the move to 4.7 and 5.5-inch screens will generate so much demand that Apple could sell 70-80 million before the year is out. But could it be possible that the killer feature of the iPhone 6 isn't the display itself, but something behind it? (Hint: I'm talking about the battery.)

I recently returned from some travels in New York and then up to Maine. Between staying in touch, relying on GPS often and dropping in and out of coverage (blame the subways and the rugged terrain of Acadia National Park), the battery on my iPhone would not have made it through a single one of my 9 days away from home without help from a charger or an external booster. Rival Samsung has taken to mocking the mediocre battery in the iPhone in a campaign called ' Wall Huggers.' The criticism is at least somewhat fair.

But aside from the obvious benefits of a bigger screen - better video, more fun gaming, easier reading, et al. - a more subtle benefit comes from merely having a larger phone. Because the other internal components don't need to grow in size, there is more room for a larger battery inside. The first time I raised this here at Forbes was January of 2013, 20 months ago; it's certain I wasn't the first to notice.

The current iPhone 5s has a capacity of 1560 milliamp hours (that's abbreviated mAh and if you don't understand what it means, just hang on). While reports from the rumor mill have been mixed on this, the latest parts leaks suggest the following: The 4.7 model will have 2100 mAh and the 5.5 will have 2915 mAh. Those totals represent increases of 35% and 85% respectively over the existing top-end model.

What we can't do is extrapolate that into a real-world battery life increase. Apple will replace the processor in the new phones with a newer design that's more capable (bad for battery life) but is manufactured using a more state-of-the-art chip 20nm fabrication process (good for it). It's also refining iOS, which could improve things on the battery front (though there is scant evidence of that from the beta other than that you get insight into which apps are battery hogs).

It's very likely that the two models will have essentially identical parts inside save for the screens, which will vary in one way and might in another. The one certain difference is that the 5.5-inch model will require a more powerful LED assembly for illumination. In and of itself, though, that won't negate what appears to be a substantial advantage for the phablet-sized model. The slightly higher power budget for lighting will minimally affect battery life. What could cut into it is resolution. If Apple builds more pixels into the phablet than to the 'plain' iPhone 6, the processing required to redraw those extra pixels will erode the benefit of the larger battery. All that said, the pre-sale bet is that the phablet will have longer battery life than the standard phone because of its substantial capacity edge. And if the two models pack an equal number of pixels, some might choose the phablet solely on that basis.

Of course, an important caveat applies. Earlier this year, after a particularly battery-sucking day in San Francisco, I tweeted this:

Rogo's Law: Smartphone usage will expand to consume all available battery life.

- Mark Rogowsky (@maxrogo) June 9, 2014

Because I write about this stuff, I try to pay attention to things like how much of the battery I could use in a given day if it weren't so constrained. And the sobering reality is that even with a doubling of capacity, with extensive use, I'm confident that many of you could run down an iPhone before heading home for dinner. What many of us end of doing is keeping one eye on the battery meter and modulating our usage so that doesn't happen. This might mean not playing another 10 minutes of Candy Crush at lunch or perhaps not updating the score of the game so often.

Whatever it is you aren't doing, a new iPhone should allow you to do more of. But even if you have a Galaxy S5, which incidentally clocks in at 2800 mAh, you can't just sit on your phone for hours surfing and running apps, then hop into a car and use GPS navigation off the battery, and finally expect to be on a conference call after that. While the Galaxy lets you hug the wall less than today's iPhone - and perhaps even less than the iPhone 6 - it doesn't offer the kind of all-day battery life that a Macbook Air or current iPad does. With each of those, it's actually difficult to run down the battery during normal usage if you start fully charged in the morning.

Two main reasons come into play. First, the bigger devices simply have much larger batteries. While their larger screens and sometimes more thirsty processors (the iPad's brain is basically the same as that in the iPhone though it runs a bit faster in the iPad Air) consume a great deal more power than those in the iPhone, the batteries are gigantic by comparison. Even the iPad Mini uses a battery 4 times larger than the one in the iPhone.

Secondly, though, the iPhone's cellular radios and sometimes frequent use of GPS are taxing on the battery. Most people don't have the 4G variants of the iPad and, of course, no one does on their Apple laptops as no such configuration is offered. The LTE radio, in particular, is a power hog. I've found at times when I want to remain loosely connected on my iPhone disabling LTE in the settings goes a long way. (For whatever it's worth, in the past week, my phone reports that 17% of the battery usage is due to Safari, 12% to the Phone app and 11% to Twitter. Keeping in mind that I'm running the iOS beta, all of those numbers should be taken with a large grain of salt.)

Looking at the iPhones competitive weaknesses, it's been hard not to notice the small screen for a long time now. But quietly, other manufacturers have also gone from offering 4G phones that wouldn't last half as long as today's iPhone to running far longer. And the truth is a smartphone without power - or one whose power you're carefully saving - isn't especially useful. Apple has been aware of this for a long time. Going back 2 years to the iPhone 5 announcement, the company was touting record thinness and its best battery life. But the results of that equation were often disappointing. Looking ahead to next month, Apple is likely again to talk up the iPhone being thinner than ever. But this time when it mentions the battery, it should deliver some meaningful results behind its claims. That's a change all iPhone purchasers can look forward to.

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