How to ?

Published on April 26th, 2017 | by Technable


How to Conserve Battery Power in Wearable Devices

How to Conserve Battery Power in Wearable Devices

You are halfway through your workout, and you want to check your progress and see how many steps you have taken so far. You press the button on your fitness tracker and…nothing. It seems the battery ran out of steam before you did. It’s not the end of the world, and you can still finish your workout, but it’s annoying that it won’t be tracked and added to your overall progress.

Battery arm powerBattery life is a major issue in the design of wearable devices. While most have the ability to be recharged via USB, it’s not always convenient to have to wait a few hours to get the device back up to full power. Devices themselves have become more powerful in recent years, with many able to operate for several weeks without a recharge; some will even operate for several years without a recharge. Still, the need to balance the need for power with the comparatively tiny space available for batteries is a challenge, and one that engineers are looking to overcome with a few creative solutions.

Voltage Regulators

One of the best ways to increase battery life is to decrease the amount of power being used. Different parts of a wearable device, including the sensors, the display, and the radio use power, each of which is powered by its own DC/DC converter from the voltage supply.  However, because of the small space inside the wearable, it hasn’t always been possible to incorporate the necessary voltage regulator, meaning that every component of the device is drawing from the same power source, draining the battery faster. The latest generation of voltage regulators, though, are tiny and powerful, allowing engineers to provide the same amount of power as larger devices, while still preserving the smaller battery size in the wearable.

Energy Harvesting

Energy harvesting takes advantage of the fact that wearable devices are worn on the skin, and captures energy from the body, typically either heat or motion, or from the environment. In most cases, the energy harvested on its own will not amount to enough to power a device, but when paired with a powerful converter, the millivolts that are harvested can provide enough of a voltage boost to charge a fitness tracker battery, or extend the battery life of a smartwatch. Energy harvesting technology is still relatively new, and not yet widely available, but it is showing promise for some extended battery life.

Microcontrollers and More

Arm battery powerWhen trying to conserve battery life in a wearable, it’s important to consider every aspect of the device and what components are draining the power. One common way to reduce battery power is to leave the functions that consume the most power to another device, such as a smartphone or tablet. For example, your fitness tracker might only collect data about your activity and show you the number of steps you take or the length of your workout on the face of the device.  For greater insights, you must sync the device to your phone or tablet, which will then process the data and reveal more information.

Even with some functions being handled by other devices, though, a wearable still needs a microcontroller and sensors, both of which drain a significant amount of power. Device engineers are focusing on MCUs that offer plenty of reliable power while still conserving power. For example, many now offer sleep modes to save power. Sensors, an integral part of wearables function, also continue to improve. Incorporating low-power sensors and digital signal conditioning can preserve the battery life of a wearable device.

Power-saving advances are coming at such a fast rate that it’s almost inevitable that charging wearables will eventually become a thing of the past. It’s likely that within the near future, wearables will be equipped with lifetime batteries, or at the very least, be equipped with wireless charging capabilities that allow users to power the device while going about their activities. In the meantime, though, engineers are working on ways to reduce and maximize the power of wearables to ensure that they remain as useful as possible and avoid frustrating users, while still keeping costs reasonable. When this happens, you won’t ever have to face a dead battery at the worst possible time again.

Tech News, Reviews, Tips and Tricks

Tags: , , , ,

About the Author

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to Top ↑