Impact of Temperature on embedded or IoT device Battery Life
One of the key factors affecting battery performance in IoT devices is temperature. While datasheets often show battery performance at room temperature, real-world environments can vary, causing significant changes in battery behavior. Temperature influences not just the battery's capacity but also the power consumption of the device's components.
How Temperature Impacts Battery Performance
Batteries function optimally at room temperature, but extreme heat or cold can degrade their performance. Here's how:
The Effect on IoT Devices
For IoT and embedded systems—often deployed in a variety of environments—temperature fluctuations can drastically impact performance. Consider an IoT solution for waste management deployed in locations with extreme temperatures. In such cases, finding the right battery for all environmental conditions becomes challenging, impacting product development timelines and costs.
Choosing the Right Battery for Cold Conditions: Lithium vs. Alkaline
Finding the right energy source that covers the diverse temperature settings can be challenging. In cold environments, alkaline batteries tend to struggle, as they can't supply enough current, leading to reduced battery life. On the other hand, lithium batteries generally perform better, even in colder weather. However, even lithium batteries are not immune to temperature effects. For instance, a 190mAh LiPo battery, with an operating range of -20°C to +60°C, may still experience significant capacity loss due to small temperature variations. In short, this means: measure!
Testing Beyond Datasheets
A battery's performance can't be fully judged by its datasheet alone. It's critical to test batteries under the actual conditions they'll encounter. For example, when testing a 190mAh LiPo battery at -10°C using the Otii Ace Pro and Otii Battery Toolbox, the results showed extremely high internal resistance. This resistance caused the battery voltage to drop, which, in turn, led to system failures like brownouts and resets. In this case, despite the battery's broad temperature range on paper, the real-world performance was far less reliable.
Figures 1, 2 and 3 show the measured and analyzed battery’s internal resistance and open circuit voltage.
Figures above show the impact of temperature on IoT battery performance and thus battery life.
Conclusion: Don’t Guess—Measure!
The key takeaway is that to ensure your IoT device operates efficiently in varying temperatures, you must test your batteries under real conditions, not just rely on the manufacturer's datasheet. Make sure to measure your device's energy consumption in different modes (standby, sleep, active) and correlate that data with the temperature extremes your product will encounter.
Even if you’re using lithium batteries, known for their performance, they won’t always perform as expected. The only way to avoid nasty surprises is to measure and profile the batteries you intend to use in your product thoroughly. As above, don’t guess – measure!
Want to learn more about battery performance and optimization? Visit Qoitech to explore in-depth testing tools like the Otii Ace Pro and Otii Battery Toolbox.