Remote Operations Need Peak-Performance Batteries

Summary

Inexpensive off-the-shelf solutions may be adequate for certain consumer electronic devices powered by alkaline or lithium-ion batteries, especially when the batteries are easily replaceable and operate in moderate environments. However, consumer batteries typically do not meet the needs of industrial applications, especially those that involve hard-to-access locations, extreme environments and large-scale installations where multiple simultaneous battery failures could be highly disruptive and costly.

Specifying an ultra-long-life lithium battery requires detailed due diligence to understand the power requirements and challenges specific to each application. This process can be facilitated by a qualified applications engineer who—using proprietary data intelligence—can help identify the optimal power supply solution that provides the best long-term value.
 

Applications matter

Too often, the battery specification process is treated as an afterthought rather than a crucial step in maximizing product performance and cost effectiveness. Understanding application-specific power needs and validating the choice of battery is essential to ensuring reliable operation in remote or extreme environments where replacement is costly or impossible.

Design optimization starts by understanding each application’s unique performance requirements. The answer can vary depending on whether the device is providing backup power or is serving as the main power source, whether extended shelf life is necessary, whether the power demand calls for a primary cell or if it requires energy harvesting coupled with rechargeable Li-ion batteries. Answers to questions like these can vary significantly across Industrial Internet of Things (IIoT) applications like supervisory control and data acquisition (SCADA), process control, robotics, asset tracking, safety systems, environmental monitoring, machine-to-machine (M2M), machine learning (ML) and wireless networks.

Key considerations for specifying a battery include electrical, environmental, size and weight.

Electrical requirements. Start by knowing maximum, nominal and minimum voltage needs; higher voltage batteries may reduce the number needed.

Battery capacity, measured in Ampere-hours (Ah), determines the cell’s maximum theoretical life based on annual energy consumption. High capacity and energy density are crucial for miniaturization. Calculating the average current drawn helps estimate annual losses in capacity. High pulses, if needed, should also be considered for advanced functions such as two-way wireless communications. Predicting capacity loss also involves accounting for storage time and expected losses due to self-discharge.

Environmental requirements. Extreme temperatures impact battery performance by reducing capacity, causing voltage drops, and increasing self-discharge rates. Some battery chemistries perform better under such conditions (see Table 1).

A structural integrity application

Resensys provides a powerful platform for protecting infrastructure systems against aging and malfunction by remotely monitoring strain (stress), vibration (acceleration), displacement, crack activity, tilt, inclination, temperature and humidity. These high-precision sensors provide durable and reliable structural-monitoring solutions for bridges, tunnels, buildings, dams and cranes, to name a few.

Resensys wireless sensors are mounted beneath bridge trusses (Figure 1) to measure structural stress. These locations are highly inaccessible and the use of a bobbin-type LiSOCl₂ battery serves to maximize return on investment by extending operating life and by increasing product reliability in harsh environments.

High pulses for wireless communications

Certain low-power remote wireless devices require high pulses up to 15 A to power remote wireless communications. Standard bobbin-type LiSOCl₂ cells can’t provide these pulses due to their low-rate design.

However, a hybrid solution has been developed that combines a standard bobbin-type LiSOCl₂ cell for low-level base current in combination with a patented hybrid layer capacitor (HLC) that generates pulses up to 15 A when needed. As the cell nears its end-of-life, the HLC exhibits a voltage plateau that indicates a “low battery” status.

While consumer devices often use supercapacitors for similar purposes, they are typically unsuitable for industrial applications due to limitations like short power duration, linear discharge, low capacity, low energy density and high self-discharge rates. Supercapacitors linked in series require expensive cell-balancing circuits, which drain extra current, thereby reducing battery life further.
 

Ask an expert

With remote applications in hard-to-reach locations, the ideal battery-powered solution should last for the entire lifetime of the device to minimize the cost of ownership. However, short-term test data often fails to predict long-term performance accurately. An experienced applications engineer can help you choose the ideal battery by reviewing your power requirements and interpreting test data to identify the solution that meets your performance criteria with minimal trade-offs.

The most reliable indicator of expected battery life is in-field performance data from similar devices operating under equivalent conditions. A qualified applications engineer can help you identify a power management solution that extends battery life, improves reliability and maximizes your return on investment.

_{This feature originally appeared in the May 2025 edition of Automation.com Monthly.}