Feature: Sensors
Shrinking sensors
need small, long-lasting
batteries By Robert Brown, Marketing Executive, Accutronics
F
ortune Business Insights forecasts that the home automation market will be worth about $114bn annually by 2025, growing at a CAGR of 12.1% from 2017’s $45.8bn. T ese fi gures are driven by mobile phones (research shows that people generally spend on average three hours and 15 minutes on their phones every day)
and the adoption of the Internet of T ings (IoT) into homes for security as well as accessibility, especially for people with physical impairments or mobility issues. T e growth of smart home devices has been infl uenced – and in turn,
accelerated – by the shrinking footprint of sensors and equipment. One example is the smoke alarm, which is transitioning from 9V batteries to smaller 3V batteries, such as the CR123A cells that were originally used exclusively in cameras.
The rise of the CR123A CR123A batteries are ideal for battery-powered smart sensors, because they combine a lightweight and compact footprint with high power capacities. Yet, as with all batteries, not all CR123A batteries are the same. Design engineers should specify CR123A batteries with very specifi c characteristics to make the most of their product. Besides high capacity, which means extended operating time for sensors, engineers should look for batteries with minimal self-discharge and a gentle voltage curve over their lifespan. T e steady voltage curve is particularly important because it directly impacts overall sensor performance. T e voltage curve indicates how the current draw of the battery changes over time, with a gentle curve meaning the battery’s performance is consistent until the energy is depleted. T is is a common characteristic in CR123A batteries with lithium chemistry, such as Ultralife’s lithium manganese dioxide battery for smart sensors. T ese batteries have an improved internal spiral construction that provides higher capacity.
Securing smart homes Although CR123A batteries are integral to many of the latest smart- home technologies, they may not be best for all applications. For example, security systems such as smartphone-synced cameras and smart locks are among the most popular smart-home technologies. In some cases these systems can be wired into the mains network, with batteries as a backup.
Smart home lighting However, smart locks are oſt en retrofi tted into existing doors,
which makes wiring impractical. So, batteries must be used and they must provide reliable, long-lasting performance, as an unexpected fault in the battery could result in someone being locked out of their home. But something like a smart lock requires a specifi c type of battery with a thin, small footprint while still providing a stable discharge curve to ensure consistent discharge, high energy density and a wide operating temperature. T e optimum choice to meet these unique set of requirements is a
battery that uses thin-cell technology, specifi cally developed to meet the demanding requirements of connected devices. T in-cell batteries balance high power density and capacity against a slim profi le – as thin as 1.25mm. T ese batteries are constructed in a pouch with square cells rather than a square arrangement of round cells, which allows more cells to be packed into a limited space. Combining high capacity with slimline design makes thin-cell
technology ideal in several security applications, including sensors in home motion detection. T ese sensors are designed to be discreet, so the minimal footprint of a thin-cell battery and a typical capacity of 1600mAh ensure compact yet long-life sensors.
Ensuring lasting connectivity Of course, central to these innovations in smart-home battery innovations is the need for reliability and safety. Particularly in the case of primary CR123A batteries, cheaper options may seem viable, but their low cost is oſt en at the expense of safety, reliability, capacity and performance. In a home-automation device where convenience is expected, or in security systems where reliability is esential, batteries or cells from untrusted suppliers are unsuitable. For electronic design engineers, the best option is to partner with a
trusted battery manufacturer such as Accutronics, who can ensure that standards of quality are maintained and that batteries deliver the needed performance. In addition, working closely with battery manufacturers also allows designers to ensure that the most suitable battery is specifi ed. Although many of us don’t give a second thought to battery selection
in our domestic devices, that is quickly changing due to the rise of smart technologies. For now, the growing need for smarter batteries, built on engineering previously reserved for professional applications, means that electronic design engineers should consider the battery as carefully as any other component.
www.electronicsworld.co.uk April 2021 29
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44
