Smartphone Batteries Explained
In this article, we’ll look at smartphone battery technologies, how to extend your battery life, and what phone accessories exist to further this goal.
Let’s start with a brief history lesson. The two main battery technologies used in smartphones today are Lithium Ion and Lithium Polymer. Lithium Ion batteries were originally proposed in the 1970s, and were released commercially in the 1990s. They proved popular in powering the mobile devices that became widely popular in the 1990s, such as laptops, video cameras and mobile phones. This was due to their light, space-efficient and flexible construction and lack of memory effect.
Lithium Polymer batteries are an evolution of the same concept, developed in the mid 1990s. The difference between these similarly named battery technologies is that a Lithium Polymer battery holds its lithium-salt electrolyte in a solid polymer composite, whilst a Lithium Ion battery keeps the electrolyte in an organic solvent.
In practical terms, Lithium Polymer batteries tend to be more reliable, more robust and cheaper to manufacture than Lithium Ion batteries. They can also be formed into almost any shape and tend to be slightly lighter, a definite advantage when designing a complex and dense device such as a smartphone. There are no significant differences in charge capacity, charge time or lifespan.
Of course, battery technology isn’t standing still – batteries are a large and growing business, as mobile technology continues to proliferate. One interesting new development, published just last week in the Journal of Advanced Materials, solves a long-standing problem.
Silicon had been identified as having the potential to store up to ten times more energy than materials used today, but tends to grow and shrink under charge, quickly breaking down the battery. A new polymer developed at Berkeley prevents this breakdown, allowing their prototype to absorb eight times the charge of Lithium without breaking. It’ll be a while before this technology is prepared, but it’s good to know that the increasing energy costs of bigger screens and faster processors will be matched with more capacious batteries.
With current technology, smartphones tend to last only hours before needing a recharge. The iPhone 4S boasts eight hours of 3G talk time, whilst the Samsung Galaxy S2 lasts eight hours and forty minutes. You can increase this a fair amount by turning off features, such as Wi-Fi, 3G and Bluetooth, when you’re not using them. Turning down your screen’s brightness and automatic syncing also helps, but it comes to a point where you’re rather jeopardising the whole point of having a smartphone in pursuit of extra battery life.
A more sensible idea is to make use of the whole host of mobile phone accessories designed expressly for increasing your phone’s battery life. There are three main categories: chargers, extended batteries, and external batteries.
Using a charger is a fairly simple strategy – instead of increasing your phone’s recharging capabilities, you can just ensure that it remains charged more often. While you normally just get a mains adapter, it’s also possible to get USB car chargers and docks, which keep your phone topped up whilst you’re driving and at your desk, respectively.
Most people do this already though, so let’s move onto extended batteries. These batteries come with a greater capacity than the original battery that came with your phone, granting you longer use of your phone. If your phone consistently dies an hour or two before you get home, then an extended battery can be just the ticket.
Some extended batteries are the same size as your original battery, so it’s just a matter of exchanging them. Other batteries are bigger than the original one, so they typically come with a replacement back cover that fits the new size. This means that other accessories, such as cases or docks won’t fit, so be wary when ordering this type of extended battery. Of course, you do tend to achieve much higher capacities when unconstrained by size, so there’s certainly a trade-off there.
The final and perhaps most convenient way of extending your battery life is to use an external battery pack. These self-contained batteries are charged at home while you charge your normal phone, and then taken with you when you go out. If your phone is running low on power, just connect the external battery to start recharging it.
As the entire assembly is self-contained, you can achieve much longer battery lives without making your phone bulky – you only need to have it attached when you really need it. The external batteries also can be much bigger and more capacious, providing up to two or three times the battery life of your phone. Battery cases also fall in this category, although you’d typically not remove a battery case as often as an external battery pack.
With a few well chosen accessories, you can achieve a smartphone that stays on all day without sacrificing the bells and whistles that made you buy it in the first place. It’s not a silicon battery, but hey, we’ll take what we can get.