Battery Capacity and Consumer Satisfaction
Powering Our Mobile Future — Part 3
The equation below shows the relationship between battery capacity (supply) and consumer satisfaction (demand) in a modern mobile device. The first and second posts in this series examined the role of battery life and user experience & functionality, respectively, in consumers’ satisfaction with their mobile devices. This post examines the battery capacity side of the equation.
The simplest way to increase battery energy capacity is to increase battery size. But with consumer mobile devices, there is little latitude to significantly increase the size of the battery. The form factor of smartphones, smartwatches, and smart glasses are largely established by user ergonomics and preferences.
With smartphones, designers have been able to increase battery size behind larger displays, which appeals to users that watch videos on their smartphones. But the increased energy supply of the larger battery primarily supports the increased energy demands of the display.
Smartwatches offer even less latitude to increase battery size than smartphones. The display size of smartwatches from Apple and Samsung with cellular connectivity to make calls, send texts, stream music, download apps, and do anything else that requires an internet connection are about 1.6 inches. These smartwatches with full-color, smartphone-like displays are estimated to last about 18 to 24 hours on a single charge. The form factor (height, width, and thickness) of smartwatches is well established, and there is very little latitude to significantly increase battery size.
AR glasses will most likely follow a path to the consumer market similar to that taken by smartwatches. The first round of viable consumer AR glasses probably won’t be stand alone. Instead, they will be tethered to a smartphone or other device that provides most of the computing and battery power. But for AR glasses to achieve mass-market adoption by consumers, they must get smaller, lighter, and more powerful. Consumers will want to wear standard-size glasses in public, not over-sized goggles, and this will greatly limit onboard battery size and weight.
With mobile device battery size limitations, the only capacity performance lever is energy density. Another significant increase in battery energy density is needed to continue innovation in mobile devices.
The Enovix 3D Silicon™ lithium-ion battery provides a step-change increase in energy density. Our battery cells are designed to deliver higher energy density over standard lithium-ion batteries in certain currently available consumer electronic products. Increased energy density is essential to support compute-intensive applications in premium consumer electronics, such as wearables, mobile phones and laptop/tablet platforms. Mobile device designers and producers can utilize this step-change increase in energy density to design wearable devices that meet the minimum battery life threshold required by consumers to widely adopt new wearable devices. Once that threshold is achieved, they can use an energy density advantage to create differentiated user experiences and device functionality, or to decrease physical battery size and weight to compete based on device form factor and design, or they can do both.
The first commercial lithium-ion (Li-ion) battery, commercialized in 1991, significantly increased energy density compared to the nickel-cadmium battery. Without this step-change increase in energy density, the brick-size cell phone of the 1980s would never have evolved to today’s sleek, sophisticated smartphones. However, from 1991 to 2020, the Li-ion battery has only increased its energy density on average less than 4.4% annually. As it was nearly 30 years ago, continued innovation leading to greater consumer satisfaction is the ultimate value of a step-change increase in battery energy density. Enovix is delivering a step-change increase in energy density, just in time for the future.