How batteries are powering the wireless revolution
Saft has been making batteries and battery systems for all types of wireless devices for 50 years.
Smart batteries for smart meters
In the West, it’s easy to take our water supply for granted. We turn on the faucet and water flows out. However, much is wasted on its way to us, predominantly because of aging infrastructure. A 2009 European Environment Agency report into leaky pipes found that up to 50 percent of the supply was lost to leaks in Bulgaria, 30 percent in France and around 20 percent in the UK.
Not only does this increase prices, but it also wastes an increasingly precious resource. UN-Water warns that, by 2025, 1.8 billion people will be living in countries or regions with absolute water scarcity.
One way that western water companies are combatting losses is by installing smart meters across the network. These detect leaks quickly, enabling the supply to be cut off. A smart meter in your home might alert the water company to a leak if it shows you continue to use water right through the night, for example. Others can be installed on the pipes themselves, allowing the company to spot leaks between the treatment plant and the premises.
But water companies aren’t the only ones making increased use of smart meters. Energy companies have taken to them to give a more accurate measure of gas and electricity use. They can also nudge householders and businesses into using energy more efficiently by showing them just how much energy every appliance is using. These meters are often designed for more than 20 years of uninterrupted use in harsh, outdoor environments, so the batteries must be designed to last just as long.
The technology the metering companies rely on is the primary lithium thionyl chloride (Li-SOCl2) from Saft, and its subsidiary company Tadiran. These batteries have enabled a new generation of meters that can save energy and money. It used to be the case that meters were mechanical and had to be read manually, once a month or once a quarter. After battery powered electronics were added, meters could be read over short distances, so that the meter reader would be able to save a little time at each stop by not having to get out of their car. The present generation of remote, smart meters don’t need to be read by a person at all; they can transmit all the relevant information back to base automatically. Batteries are used instead of line power for safety reasons, to keep costs down and to ensure that the customer cannot cut the power to the meter.
A 50-year success story in the city
The batteries making this possible were developed in the 1970s from electrochemistry invented by Saft in 1969. The concept of Li-SOCl2 was developed by Jean-Paul Gabano, an outstanding engineer and researcher who spent 27 years at Saft. It still forms the basis of most of Saft’s primary lithium batteries today.
At the time, Saft and Tadiran (acquired by Saft in 2001), were leaders in the technology. The batteries were developed for computer motherboards, providing the power to keep the system clock running when the machine was powered off. This was a booming market in the 1970s, but as computers began to shrink so the batteries were replaced by coin-sized cells. They soon found a new use, however, in the home security market, powering intruder alarms. The low power needs of such devices meant that batteries were a good alternative to wired power.
Another use emerged at around the same time; the E-ZPass system employed to collect tolls on roads, bridges and tunnels. With the arrival of long-range transponders, it was possible to replace manned toll booths with dashboard devices that charged a fee without the vehicle needing to stop. Saft has more than 100 million batteries in these gadgets – able to withstand the temperatures of 85°C sometimes reached by the inside of a car.
The future… new applications & new solutions
New uses for lightweight and reliable Li-SOCl2 batteries are still appearing. In smart cities, the battery can also be used to power tools such as parking sensors that will share information with the local network, allowing cars to be directed to the nearest available space. Air quality or structures monitoring are also new applications for which wireless, autonomous sensors are key components.
Asset tracking devices are another example. While they used to require a lot of power to be able to communicate with satellites, today’s modern units transmit over a shorter range to cellphone towers, which then relay the signal to where it needs to go. This means less power is required and Li-SOCl2 primary cells can be easily used.
Other primary lithium solutions, also designed and manufactured at Saft, can power autonomous or connected devices. They include lithium-manganese dioxide (Li-MnO2) and hybrid solutions such as Tadiran Pulses PlusTM, combining Li-SOCl2 chemistry with a unique Hybrid Layer Capacitor (HLC).
Fifty years on from its beginnings as a solution for the nascent personal computer industry, the primary lithium cell is a technology that still has its best days ahead of it.
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