Collaboration for maintenance-free IoT devices

The system was developed by combining NGK’s EnerCera battery series and Renesas’ RE Family of ultra-low power microcontrollers (MCUs).

Data collection and utilisation are considered to be the most effective means of realising a productive life or addressing social issues. Meanwhile, actions to achieve the decarbonisation of society have been gathering momentum on a global basis. For example, Japan and many other countries around the world have adopted the goal of achieving net zero greenhouse gas emissions by 2050.

Therefore, these countries will be required to reduce their power consumption even as they deploy numerous IoT devices for data collection purposes. To realise such a society, there is a need to develop maintenance-free IoT devices that can be powered by trace amounts of electric power obtainable from energy sources in the environment, such as peripheral light, heat, and vibration energy. It also requires for a device that do not require battery replacement.

EnerCera battery series is a lithium-ion rechargeable battery featuring a high capacity, low resistance, and long life despite having a compact, ultra-thin body. EnerCera battery series is ideal as a power source for maintenance-free IoT devices, since it can efficiently charge itself with a weak current and output an intermittent large current to drive functions such as sensing and communication.

To power a device with the electric power stored in the battery, an MCU that links the battery with sensor ICs, communication ICs, and other components is needed. For this reason, NGK has developed a reference design for promoting the widespread adoption of maintenance-free IoT devices, together with Renesas’ RE Family MCUs that realise industry-leading ultra-low power consumption.

“We are confident that the combination of NGK’s battery technology and Renesas’ ultra-low power consumption technology will accelerate the widespread adoption of battery maintenance-free IoT devices,” said Makoto Mizokuchi, Head of Low Power Products Department at Renesas.

“I’m convinced that NGK’s collaboration with Renesas will promote the development of maintenance-free IoT devices, thereby helping to solve social issues while realising a decarbonised society,” said Iwao Ohwada, Vice President and General Manager, Advanced Device Components Div., Electronics Business Group at NGK.

As the first phase of collaboration, NGK and Renesas jointly-developed a reference design for wireless outdoor air quality sensing systems powered by solar cells. Monitoring pollution levels in outdoor air provides valuable insights on the associated health effects from elevated levels. Conventional sensing systems have presented problems such as requiring power cables due to their large power consumption and thus being subject to restrictions on sites where they could be installed.

The combination of ultra-low power RE MCUs and low resistance, high-capacity EnerCera batteries will enable constant measurement of outdoor air quality indexes at all times, even with only trace amounts of intermittent electric power obtainable from the solar cells. This will allow monitoring of the degree of atmospheric pollution without having to devote time and effort to power cable wiring and battery replacement. The system can also support long-distance radio communications such as low-power wide-area (LPWA) network technologies, enabling centralised management of measurements from numerous sensors in the field.

Not only for environmental monitoring but also a variety of other fields, NGK and Renesas will continue to jointly-develop reference designs to realise the widespread adoption of maintenance-free IoT devices that combine the EnerCera battery series and RE Family MCUs.