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We are slaves of electricity. Outwardly, it might appear that Tesla and Edison wrangled electricity into submission — into usable power — but really, ever since the first commercial light bulb and high-fidelity telegraph, electricity has ruled the lives of men.
Almost every facet of contemporary society is dictated by the properties of electricity. Like fresh water, sanitation, and education, access to electrical power can make or break a community.
The tenacity of electric-powered devices and machines is unbelievably vast. With modern robotics, there is almost nothing that electricity can’t do — and a lot that electricity can do that humans can’t. The amount of work performed by electricity is beyond belief, too. From sowing crops to preparing food, from making computer chips to manufacturing cars, electricity does so much work that would otherwise have to be done by humans.
Just for a moment, suspend your scientific beliefs and imagine that electricity suddenly ceased to exist. Waking up, your alarm wouldn’t work. Unless you have a gas grill, you can say goodbye to your morning toast. Your car wouldn’t start (or brake, or steer, or do anything really). Trains, without signaling, would be dead weight. Automatic doors at the entrance to your office, school, or favorite coffee shop would remain resolutely shut. Your PC, your DVD player, your wireless router, your digital camera, your smartphone — all computers everywhere would be dead.
Which brings me neatly onto the topic of batteries. At their most basic, batteries are devices that store electrical power. Until very recently, the archetypal battery would be an alkaline AA — useful for listening to music on your Walkman, or powering your RC car controller; batteries were useful, but hardly vital. Over the last few years, though, a dramatic shift has occurred. As chip makers — such as Intel, AMD, and Qualcomm — have refined their processes, computers have become steadily more mobile: Laptops, then mobile phones, then netbooks, and finally smartphones and tablets. This year, in the US, 76% of all PCs sold will be laptops, and tablets will outsell desktops. In the next couple of years, it is predicted that 75% of Americans will own a smartphone.
In short, the vast majority of computer users now rely on battery-powered devices — which is a problem, because battery technology isn’t developing at a pace that can keep up with our usage. While we’re almost at the stage where silicon chips are assembled atom by atom, battery technology has remained virtually unchanged since Alessandro Volta created the first battery in 1800: Two electrodes with an electrolyte between them. While semiconductor complexity (processors and LCD displays) has generally doubled every 18 months in accordance with Moore’s law, battery capacity has slowly clawed its way upwards. Even more worryingly, theoretically there is no better electrode than lithium when it comes to electrochemical potential or energy-to-weight ratio — lithium-based batteries are as good as it gets.In practice, this means that we’re heading towards a battery crunch, where batteries cannot keep up with our increasingly mobile lifestyle. A good example is the iPad 3: Higher-resolution screens require more power to control and more power to illuminate. As a result, the iPad 3’s li-ion battery is 70% larger than the one in the iPad 2 (42.5 watt-hours vs. 25), and yet they both have the same 10-hour battery life. A larger battery and stronger backlight means that the iPad 3 is both heavier and thicker than the iPad 2, too — all for a high-res screen. In the realm of high technology, it is exceedingly rare for a follow-up device to be bigger than its predecessor — but that’s the battery crunch for you.
Mobile LTE is another fine example: It might be faster than UMTS 3G, but it consumes a lot more power in the process. First-generation LTE devices, such as the HTC Thunderbolt, famously ran out of juice after just a few hours of LTE connectivity. Ditto RAM and non-volatile storage: As capacities and transfer speeds increase, as does power consumption. The fact of the matter is that high-res screens and wireless communications (WiFi, cellular) consume the lion’s share of your battery’s capacity — and, unless we all come to an agreement that high-PPI displays and mobile internet access are pointless, this won’t change.
While the next few years will likely be full of beautiful, powerful devices that only last a few hours between charges, there is some light at the end of the tunnel. Intel, AMD, and ARM licensees are all frantically battling to produce the most efficient chips for mobile devices. Sharp’s IGZO and Samsung’s LTPS promise to significantly reduce the display’s power consumption. With the recent shift to 28 and 22nm processes, wireless radios consume less power. At the end of the day, though, we’re talking about reductions of 10 or 20% over a few years, which is unlikely to be enough to offset the unstoppable double whammy of Moore’s law and society’s shift towards mobile, ubiquitous computing.
Ultimately, our biggest hope lies in battery technology itself. One of the biggest jumps in battery capacity will come from replacing graphite anodes (the positive electrode) with silicon nanotubes. The same group (Yi Cui and his team at Stanford University) is working on an everlasting battery that uses water as an electrolyte — but that battery is angled towards power grid storage (another equally huge topic, especially with the growth of solar power). Also on another tack, IBM is working on a lithium-air battery that’s a tenth of the size/weight of conventional li-ion batteries — it will be primarily targeted at electric cars, but could eventually (10+ years) be used to power mobile devices.
In all cases, we shouldn’t expect a significant boost to battery capacity for at least 5 years — and even then, who knows if the gains will be large enough to catch up with semiconductor tech. The battery crunch is here to stay. How will manufacturers react? So far, consumers seem quite happy with devices that eschew battery life in favor of screen size and performance — and ultimately, consumers are king, right? Will business and travel users fight back and demand low-resolution, long-life devices? Personally, I’m going to buy five low-res ultrabooks and keep them in the attic — hopefully that’ll buy me enough time until the battery crunch passes.