Whatever benchmark wearables market size number you believe, whether we’ll see 14M or 200M units shipped by 2016, one thing is clear: Unless we quickly see major innovation in battery technology, most of these units will get about as much use as the much heralded home bread making machines.
To succeed, wearables must enhance and simplify daily life, not complicate it. In the words of Hosain Rahman, the CEO of Jawbone, “all this wearable stuff is constrained by battery technology. It’s not a computing problem.” Rahman was speaking at the Reuters Global Technology Summit, discussing the current limitations to the wearable device movement. Consider that some reviewers are only getting 5 hours of battery life when using Google Glass under normal conditions: not nearly enough for a full day away from a charger.
Short-term solutions to battery limitations such as PWRGlass—an extended battery pack attachment for Google Glass—and Vodafone’s Power Pocket—which harnesses kinetic energy from walking to charge mobile devices—won’t revolutionize wearable devices. They may, however, make a lot of money for their companies given the acuteness of the problem and the consumer demand for devices. Innovations and improvements must be made at the battery and wearable device level. Gadgets that only address the symptoms of under-developed power sources will not disrupt this market, although, like Mophie, they will have a good run. We see major upcoming improvements in three categories: wearable-optimized battery design, improved mobile recharging, and more efficient power usage.
No clear leader has yet emerged in the race to build batteries for the world’s wearable devices. Many manufacturers, however, are developing products specifically for them. One such example is Imprint Energy, which is developing zinc- instead of lithium-based batteries. The zinc base is much more stable and safer than the traditional lithium construction. As a result, Imprint’s batteries require much less packaging. This allows Imprint to screen-print batteries—similar to the method used to print designs on T-shirts—that are ultra-thin yet effective and safe. The screen-printing method also means Imprint can create batteries in completely customizable shapes to match any device.
For many devices, such as stretchable wrist- or headbands, batteries that can be folded and stretched are also necessary. In response to this need, Northwestern University and the University of Illinois created a stretchable battery that is fully capable of operating when stretched to 3 times its normal size. We suspect these stretchable, bendable batteries will appear in the next generation of fitness wearables. Considering that the only non-pliable part of the Nike FuelBand is its battery, this development brings us closer to a new wave of better-fitting, more comfortable wearable devices.
Not to be outdone by Northwestern, researchers at Harvard has also just developed a 3-D printed battery in conjunction with the University of Illinois that is smaller than a grain of rice yet potent enough to power ingestible activity trackers similar to those made by Proteus Digital Health. With the same power density as existing lithium-ion batteries and a highly adaptable design that comes from the 3-D printing process, this development is especially promising for ingestible or implantable biosensors.
While all of these developments in battery design are exciting, many industry leaders believe the stickiness of wearable technology hinges on its ability to break from its reliance on batteries. For example, at the Reuters Global Technology Summit, Soulaiman Itani—the CEO of Atheer Labs—said “remote charging … will cause a huge next leap [for wearable devices] because it breaks this dependence on the battery.”
The world of wearables may still be years from widespread remote charging, but the Wireless Power Consortium is developing a wireless charging solution that universalizes and simplifies the way we recharge our devices. The movement is called “Qi,” and it is standardizing wireless charging protocols. Any device labeled with the Qi logo will be compatible with Qi chargers. With 334 products currently compatible and more on the way, Qi-enabled chargers in public locations may soon make it easier to recharge devices on the go. Mercedes-Benz has already warmed to the idea, placing Qi chargers in their next model year cars, and some Toyotas are already Qi-enabled, so passengers can charge nearly any device while they ride. For those products not yet Qi-enabled, wireless charging cases are available that retrofit non-compatible devices.
The University of Illinois also recently developed a credit-card sized battery powerful enough to jump-start a car and charge mobile phones in an instant. The battery delivers 30 times the capacity of similar-sized batteries and recharges in 1/1000th of the time. This battery currently only exists in academia—the production costs will prohibit their use in wearable devices for some time. But if production costs can be brought down, faster-recharging batteries like this one will make wearable devices much more practical: imagine the ability to recharge Google Glass on the go by briefly tapping it on a Qi-enabled charging mat.
Another technology that has great potential to power activity tracking sensors lies in smart textiles, which has the power to fuel the future of textile sensors (see our recent coverage). In 2010, Wired featured work from Stanford University researchers, which used single-walled carbon nanotubes and attempted to use graphene to create flexible supercapacitors in fabrics. More recently, National Geographic featured Dr. Ray Baughman, director of the Alan G. MacDiarmid NanoTech Institute, who is working to develop technology that will store electrical energy for the next generation of wearable activity tracking devices.
Apple’s new M7 processor demonstrates the activity tracking industry’s need for more efficient devices. The M7, as we covered here, uses less battery power to track a user’s movements by using lower-level processing to record movement data, even when the phone is asleep.
At the hardware level, SuVolta recently demonstrated a new more efficient transistor design that lets devices run longer with the same processing speed as comparable chips. At the Hot Chips conference, SuVolta replaced the transistors on a leading chip with their own design and demonstrated the transistors’ ability to draw just half the power as the original. While the transistors aren’t meant for more powerful devices, the CTO of SuVolta—Scott Thompson—believes “computing is no longer about making $200 CPUs…it’s about $100 cell phone and wearable devices.” We agree with Thompson and believe more efficient devices are crucial to the success of the wearable tech movement.
Another exciting efficiency improvement development is ambient backscatter. This technology piggybacks existing wireless signals to transmit signals without drawing on battery power. This allows devices within a limited radius (from .5 – 6.5 miles in early tests) to transmit basic information like texts and contact information. While the data capabilities are limited at this point, the battery-free transmission of simple data could be very powerful for wearable devices. A quick video detailing ambient backscatter is below:
Battery and recharging technology could be the next area to see a breakthrough in the industry side of wearable technology. The potential for a major disruption in wearable devices via new power-related technology is high. Already, venture firms have started investing in startups in the battery and device efficiency space. For example, Kleiner Perkins recently funded LuxVue, a startup working on “low-power, micro-LED displays for consumer electronics.” According to partner John Doerr, Kleiner Perkins also recently invested in a yet-to-be-named startup capable of improving battery capacity by 300%. While this technology may still be on the horizon, another startup, Amprius, has already found success. Amprius developed batteries with better power density—up to 700 watts per liter versus 400 watts per liter for other leading batteries—and has started selling their batteries to smartphone and tablet OEMs. Multiple VCs, including VantagePoint, Trident Capital, Kleiner Perkins and Google’s Eric Schmidt, already back Amprius. We think companies like Amprius, with disruptive products and venture backing, will have the technology and resources to drive the next fundamental shifts in the wearable technology revolution.