Powering homes efficiently

Robert Brown explores the new electronic devices in the household sector, the modernisation of old ones and the advancements in battery technology that are making this possible

When people think of smart homes, voice-controlled speakers, lights and curtains come to mind. However, there are a wealth of other electronic devices that make a difference to our home lives, from safety to security and metering. 

The market for smart meters has grown exponentially, with 4.05 million smart meters installed in domestic properties in 2016, increasing to 22.2 million meters by the end of 2020. This is in part due to a government scheme for energy suppliers to install smart meters in every home in the UK, with the goal of every home being offered a smart meter by the end of the rollout.

Not only does the use of smart meters help to maximise the accuracy of gas and electricity usage data received by utility companies; automating the meter reading process means that the utility company only needs to send someone to visit the home when the smart meter battery is depleted, which can be up to ten years from the date of installation. This is a lot less frequently than the multiple visits per year required by the manual meter reading system.

Smart meters continually record energy usage, so their power consumption is characterised by very low background activity but with periodic high current pulses while measurements are being taken or during data transmission. As meters must operate without maintenance for up to ten years, the only battery chemistry that can meet the requirements is Lithium Thionyl Chloride (LiSOCl2) due to its high energy density and low self-discharge rate.

However, not all Lithium Thionyl Chloride cells are created equally and can vary by manufacturer. Ultralife has a background of manufacturing cells and battery packs for military and medical applications, where power failure is not an option. This means that batteries and cells are designed to be reliable and high-performance, which is beneficial to devices that are in constant use.

For smart meters, Accutronics’ parent company Ultralife has launched a new range of ER Generation X cells, offering two variants: spiral-wound cells that offer excellent pulse capability up to 2000mA, 1.0 second pulse, and bobbin cells that boast increased capacity and lower constant discharge current. The new cells bring a host of benefits in comparison to their predecessors, including better passivation performance and better horizontal discharge performance. 

Smoke alarm switches

Unlike smart meters where the responsibility for battery replacement lies with the utility company, smoke alarm battery replacement is often left up to the property owner, so requires a consumer-replaceable power source. 

The batteries required for these devices need to be able to operate continuously, with long idle times whilst no smoke is detected and periodic, short bursts of high current demand during testing or in the event of a fire. 

While 9V batteries have always been the norm to use in smoke alarms, in the past few years we have seen manufacturers opting to use 3V CR123A batteries in these devices, leading us to change our product portfolio accordingly. 

CR123A batteries, like the ones offered by Ultralife, utilise Lithium Manganese Dioxide (LiMn02) chemistry and offer a very low self-discharge rate, high voltage and the ability to deliver high current on demand. The new US manufactured version has an improved internal spiral construction, providing a top-tier capacity of 1500mAh.

Security and surveillance

In addition to finding a new home in smoke alarms, CR123A cells power a wealth of other sensors and detectors for safety and security purposes. Perhaps the most commonly found type of security sensor in our homes are motion detectors that form part of household alarm systems.

In such systems, battery-powered sensors are installed in each room and communicate to a central ‘hub’ if motion is detected, triggering the alarm. A reason for the increased uptake in such systems is that home insurance premiums can be affected, with discounts of between 2% and 15% applied, although not all insurance companies offer this.

CR123A cells can also power door and window entry sensors. Initially, the uptake of these devices was slowed by their tendency to trigger false alarms, but the technology has improved to minimise this. These sensors work in a similar way to smoke alarms, running idle for long periods with bursts of energy when the sensors are triggered.

Improvements to Lithium Manganese Dioxide and Lithium Thionyl Chloride cells have resulted in an increase in and improvements to the safety and security devices in our homes, as well as enabling the smart meter rollout. However, technological improvements are never-ending and Accutronics will be at the forefront of developing batteries and cells that utilise the latest chemistry, so that manufacturers can create the next-generation of devices for our homes. 

Robert Brown is marketing executive at professional battery manufacturer Accutronics.