Priority Interrupt by Steve Ciarcia Dead as a Doornail

The average person these days has dozens of portable devices. We’ve got radios, laptops, cell phones, flashlights, cameras, navigation systems, iPods, PDAs, LCD TVs, DVD players, etc. Let’s face it. We live in a gadget-happy universe. As much as we might want to deny it, we love the whole idea that science fiction is fast becoming science reality. Take cell phones as just one example. “Personal communicators” were barely thought of 20 years ago, but today you can have a cell phone with a 0.5-megapixel color view screen and features scheduling, word processing, GPS navigation and mapping, FM radio, a web browser, a TV receiver, an MP3 player, a digital camera, a video player, and a voice recorder. Cell phones are fast becoming the Swiss Army knives of our electronic universe.

 Of course, these feature-laden devices are a great idea until you turn on a few of the functions and the batteries die after about 10 min. How many times has your laptop’s battery icon claimed it has, say, 3 hours and 41 min. left, but an hour later little flashing things start appearing on the screen, warning you of a low battery and imminent shutdown? The manufacturer of the laptop neglected to tell you that the 4-hour battery life drops 30% if the screen is on (so you can actually read it), and another 50% if the Wi-Fi is running (the only reason you bought the laptop).

 Battery technology is the one critical part of our electronic universe that never heard about Moore’s law. What kind of processing improvement have we seen since 1965? A million times? I just read that disk drive capacity alone has increased over 400,000% in the last 15 years. Rechargeable battery capacity (energy density) has increased just 300% in the same period of time. All the great features we want in portable devices aren’t missing because of a lack of technology. It’s just that the available battery power can’t handle their present level of electronic integration.

Battery design is fundamentally an issue of chemistry. Battery technology hasn’t changed much because the periodic table hasn’t changed either. Every time you start your car, keep in mind that it’s using basically the same lead acid battery designed by Gaston Plante in 1859. All those NiCd batteries used in your power tools trace back to discoveries by Waldmar Jungner in 1899. Talk about a slow evolution.

 Energy density improvements in recent years are primarily the result of fiddling with the zinc-copper-lead-carbon-nickel-cadmium-mercury-lithium soup to tailor specialized power curves. The good news is that Li-ion batteries have made many of the devices we use today a reality simply because we finally have enough power to run them. The bad news is that we may not be able to tweak the chemistry much more. Conventional battery technology might still improve, but that will take a long time, and it will never result in the magic bullet that gadget manufacturers really want as a portable energy source.

In the meantime, how do we keep adding new features to all these gadgets? First, we improve efficiency. If companies want to sell portable computers with everything including the kitchen sink and more than a half-hour run-time, then they have to design special energy-efficient processors and circuitry that shut off unused buses, logic, and memory blocks. They also need to find an alternative to energy-wasting LCD backlights for portable devices with video displays. One technology with potential is organic LED (OLED) display. Of course, there are little problems. It’s expensive, fragile, and the colors fade. But hey, all that used to be true about the stuff we commonly use today.

 The ultimate solution is a fuel cell battery. On the drawing board for the last 50 years, a fuel cell is essentially a battery that combines hydrogen and oxygen to produce electricity. Conceivably, when you need to recharge, you would simply pour in a little methanol and away you would go. Like gasoline in a car engine, the appealing advantage is that, for a given volume, methanol has far greater energy density than something like Li-ion. Of course, before fuel cells become a reality, there are little issues to deal with: some fuel cells like to run at 350°C; they prefer being constant-current generators; and they’re made with expensive platinum. Plus, methanol is hard to find, and you can’t get on a plane with it. Of course, every technological advance started with lots of technical obstacles and naysayers predicting their failure. If you look at how far we’ve come, you can easily envision that fuel cell batteries will be in common use eventually. I for one never want a battery that is dead as a doornail again. I prefer the option where I can simply say, “Fill ’er up.”