Battery Power - July/August 2013 - (Page 4)

Feature From Processor to Power Management: The Copernican Moment for Portable Devices Sam Jaffe, Senior Research Analyst – Energy Navigant Research It’s hard to forget the scene from the 1987 movie Wall Street when Michael Douglas is walking down the beach in front of his Hampton’s beach house holding a two-liter bottle-sized cell phone to his head. It was the first time most of the movie’s viewers had ever seen such a thing and it made a lasting impression. Soon, these enormous devices would become the status symbol of the ages. Owning a cell phone wasn’t just about making calls. It was about being seen making calls. That hasn’t changed two and a half decades later. But the phones themselves have changed enormously. For 20 years, they continuously shrank until, in the 2001 movie Zoolander, Ben Stiller was seen holding a thimble-sized phone. Then the phones, as they gained functionality (texting, game playing, Internet access, etc.), the phones started getting bigger again. From a technological perspective, the story of the cellphone over the last 30 years has been the story of processors, the chips that actually allow you to talk wirelessly. As the processors got smaller and faster, so did the phones. And at a certain point they became so powerful and small that the phones stopped being phones and became hand-held computers. Today’s smartphones are no longer limited by their processors. A simple 1.6 GHz. Quad-core Exynos powers the Samsung Galaxy S4 (the hot phone of the moment) and allows it to perform multiple tasks simultaneously while continuously communicating with several networks and satellites. But today’s phones are limited by another component that, until now, had been an engineering afterthought: the battery. Phone purchasers usually rate battery life and battery longevity as two of the most important factors in which phone they choose. And while processors have been shrinking at an exponential rate, batteries have not. Most phones use a very similar chemistry to the same cells that went into phones a decade ago. That is about to change, as new battery chemistries and new power control architecture start to be experimented with. The battery is to tomorrow’s cell phone designs what the processor was to the past generations of phone designers. And this phenomenon is not limited to cell phones. Every portable device, from cordless drills to hand-held point-of-sale units to pacemakers, is under the same end-user pressure to improve battery charge time, power capacity and longevity while not compromising on cost and safety. Portable device designers are experiencing their Copernican moment. When Nicholas Copernicus proved in the early 16th century that the Earth revolved around the Sun, and not the other way around, it caused a scientific, philosophical and theological revolution that still echoes today. In a similar fashion, device engineers are learning that the key to making a popular device is not about how fast the CPU is, but about how well the battery performs. This transformation is happening on multiple fronts. The 4 Battery Power • July/August 2013 most important elements of it are in battery chemistry, power control design and device layout. Basic battery chemistry is flourishing, with multiple new molecules being investigated as cathodes, anodes and electrolyte. Although most of this research is being cloaked in the robes of electric vehicle enablement, the fact is that rechargeable cells for portable devices are still the largest single battery market. Most current devices use some form of lithium-ion batteries, with consumer electronics sticking to traditional lithium cobalt oxide formulations for the cathode and power tools frequently sporting lithium iron phosphate cells. However, new systems that utilize solid electrolytes promise a significant improvement in energy density and longevity. An even more promising chemistry is lithium sulfur, which could double or even triple the energy density of most devices while maintaining their useful lifetime of 24 months. Farther out in the future, emerging research around lithium oxide batteries, which utilize the oxygen in the ambient air for the cathodic reaction, could improve energy density by as much as 10-fold. Power control design in today’s cellphones is a relatively simple affair. Most phones utilize a single Texas Instruments power control processor (which costs less than a dollar when ordered in bulk) that regulates current based on feedback from three sensors that measure current, voltage and temperature. Newer power control designs monitor things like device harmonics and frequency that allow the control of the battery to be much more precise. Additionally, power control is being managed from the application end differently. For instance, the most notorious power glutton of a modern smartphone is the global positioning system (GPS) chip, which allows the phone to be precisely located and mapped. New GPS chip designs utilize different architectures to achieve as much as a four-fold reduction in power draw. Device designers are also exploring new system layouts that allow thermal management to be more easily accomplished. A typical cordless drill of five years ago, for instance, held the nickel cadmium battery cells (which are much more resilient when temperatures get high) inside the drill handle. Most lithium ion drills today have a battery pack that attaches to the bottom of the handle, separating the battery cells from the drill motor, which can generate a tremendous amount of heat. Phone, tablet and laptop computer designers are also experimenting with new system layouts that ensure that heat flow from the batteries don’t interfere with the processor, and vice versa. The utilization of pouch cells in tablet computers is a good example of this, as the large surface area pouches shed heat more quickly than traditional cylindrical cells. Another sign of the importance of power management becoming the de facto king of design specifications is the evolution of the component it dethroned: the processor. When ARM chips became the standard in cell phones and tablets, it was primarily Navigant Research Article Continued on Page 6 www.BatteryPowerOnline.com http://www.BatteryPowerOnline.com

Table of Contents for the Digital Edition of Battery Power - July/August 2013

From Processor to Power Management: The Copernican Moment for Portable Devices
The Mergers & Acquisitions Environment
ZigBee Resource Guide
Battery Take-Back Legislation: EU Speciality or Worldwide Principle of Waste Management?
Battery Pack/Assembly Manufacturer
Primary Battery Manufacturer
Secondary Battery Manufacturer
Alkaline
Lead-Acid
Lithium
Lithium-Ion
Lithium Iron Phosphate
Lithium Polymer
Manganese
Mercury
Ni-CD
Ni-MH
Silver
Thermal
Zinc
Aerospace/Aviation
Automotive
Consumer Electronics/Tools
Electric Vehicles
Industrial/Utility
Marine
Medical
Military
Renewable Energy Systems
Standby/Telecom/UPS
Accessories
Battery Assembly Equipment
Breakers
Cables/Harnesses
Capacitors
Chargers
Coatings
Components
Connectors
Consulting Services
Converters & Inverters
Dry Rooms
Electrolytes
Enclosures
Forming Systems
Holders
ICs & Semiconductors
Manufacturing Systems
Materials
Monitoring Systems
Powders
Power Supplies
Racks/Cabinets
Raw Materials
Recycling
Safety Systems & Equipment
Standby Power/UPS Systems
Testing Services
Testing Systems & Equipment
Watering Systems

Battery Power - July/August 2013