Batteries: The last, necessary frontier?

11 November 2014

Recently, I gave up my Droid Razr Maxx and switched over to a used iPhone 4S, just to give iOS a try. While I've really enjoyed all the software advantages that come with this change, I've suffered from one very noticeable, very strong disadvantage: battery life.

My iPhone can last about 12 hours on a charge under low usage; if I'm heavily using wifi or 3G (remember how the 4S doesn't have 4G?), then my effective battery life might only be 4-6 hours.

Part of the reason for this incredibly limited performance is definitely the fact that this is a used phone, and I was warned ahead of time that this would be a problem. But that doesn't help the fact that now I have to carry a charging wire everywhere I go, the fact that I bought a portable battery pack as an emergency measure, or the fact that I often think about sacrificing my laptop's battery for the sake of recharging my phone.

So, all of this experience leads me to believe in one thing: batteries are the current bottleneck in mobile development, especially in terms of software and app development.

The problem

This problem is not a new one, so why doesn't it seem to be getting better?

Having an above-average battery life is definitely a selling point for certain phones. The Razr Maxx I used to use, for example, boasted battery life of 21.5 hours of talk time, while the new iPhone 6, for example, only does up to 14 hours (the 6 Plus gets 24 though). But currently, battery life comes at a very noticeable trade-off, namely size.

Scientists acknowledge this problem and have been trying to develop a solution. One way to deal with the problem is to use the current battery technology and make it even more efficient. In the last decade or so, scientists have continued improving on the lithium ion technology, and today our batteries are both more efficient and cheaper than their predecessors. However, researchers think that we can only squeeze out at best another 30% increase in efficiency using lithium ion technology.

The other way to deal with the lithium ion battery limit is to create a new kind of battery. Scientists are actively developing new kinds of batteries, such as ones with graphene or lithium-sulphur technology, but getting these to a commercial state will take time.

The implication

The amount we want to do with our cell phones is obviously increasing. We are not only arguably doing "older" cell phone behaviors (e.g. checking email, texting) more often, but we are also developing new cell phone usage habits (e.g. watching videos, streaming music). In aggregate, we are demanding more and more from our phones and thus from our phone batteries.

So we know that we can't watch funny cat videos on our phones all day - so what? The "so what", I believe, is this: knowing that our batteries are severely limited blocks us from developing the "next level" of apps that more tightly integrate our phones into our lives.

I'll start my explanation of this with a simple, personal anecdote. I've been a slow adopter of mobile boarding passes for plane tickets. Up until just a few months ago, despite having owned a smartphone for years, I've always printed out my boarding passes to bring to the airport. Even today, I still hesitate to rely on my phone as a boarding pass, and if I'm running early enough I still prefer to use an airport self check-in kiosk to print out a physical boarding pass.

Part of the reason for this is that I've had bad experiences with the stability of various apps on my Android (completely different problem). But another major reason is that I feel like I can't rely on my phone's battery life, and the outcome of my phone dying when I need to pull out my e-boarding pass is a pretty negative situation. Even with the knowledge that things will still be ok (i.e. because I have a portable battery, or because I could always just print one out if my phone dies, or because there are these things called power sockets in the airport), I still would rather take the effort to print out a boarding pass ahead of time than to depend fully on my battery life.

I hope I'm not the only one crazy enough to be worried about this. But consider what this potentially means for other kinds of apps. Some apps either entertain us (e.g. YouTube or Facebook), or help us do something that is generally non-urgent (e.g. text messaging, looking things up on the internet).

But, there exists another category of apps - those that try to be substitutes for vital things we usually carry around with us.

Airplane boarding passes are an interesting but not every-day example of something we usually carry around with us. The objects that are truly every-day are the ones that are at the forefront of mobile app development today: credit cards (and, by proxy, cash), public transportation passes, and keys are three good examples.

What will it take for cell phones to replace these vital physical "analogues"? Yes, we will have to solve big security issues, in addition to figuring out how to make these technologies "work", from establishing standards (e.g. NFC for credit card payments) to smart UX/UI choices. But, will users adopt this new category of apps if they can't rely on their phones to be alive when they most need them to be?

Put another way, if my cell phone is to replace my credit card, will I ever make the full transition of not carrying around my credit card if I'm afraid that my phone's battery will die when I most need it? Or if my phone is actually the key to my house, will I stop carrying around my keys if I'm unsure that my battery will be alive when I come home?

I hypothesize that we as users will not give up the physical analogues without being very sure that our phones' batteries are reliable. And this new category of apps can't take off until we are comfortable giving up those physical objects.

Should software developers care?

Alongside hardware improvements in the form of battery technology, there have also been some software improvements. By doing things like devoting fewer resources to background apps, software can also make a big difference in prolonging battery life.

Should app makers care about how battery-intensive their apps are? They probably should to some degree, because having a particularly battery-hungry app can be a cost that deters users from using the app.

But, effort to solve the "vital physical analogue" problem does not have a linearly scaling impact. In other words, making your credit card replacement app 30% less battery intensive does not make it 30% more appealing. This is because we can't think about smaller, incremental improvements when we think about improving battery life. Instead, we need some kind of larger, step-function improvement in order to decrease the risk of your battery dying below a certain threshold such that users can "trust" that their phones will be availble when they need to use it for something vital.

Thus, I would actually argue that software developers don't have much to contribute towards solving the roadblock for this "next level" of apps. They can work out the software solutions to the various problems (e.g. how to have the phone communicate with a lock), but they won't be the key solvers of the biggest problem that will block adoption: battery life.


Mobile technology has really come a long, long way in a short amount of time. There have been as many hardware advances as software ones, but the next big challenge is having our phones replace certain key physical objects we carry around with us. For this challenge, hardware limitations in the form of battery life will be, I think, the biggest barrier to adoption.


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