3 Tips for Better IoT Device Battery Life

2018-10-05 | 5 min read

I absolutely hate it when my smart phone dies prematurely. Unfortunately, it’s not the only Internet of Things (IoT) device I have to worry about these days. I also own a Fitbit and an Apple Watch. When these devices die unexpectedly, I lose my ability to gather valuable data that I track as I go about my daily life. Granted, this data (steps, heart rate, etc.) doesn’t exactly qualify as mission critical, but it is vital to the quality of my life, and that means I care very much about the battery life in my IoT devices.

Most consumers do too. They care so much in fact, that they often rate battery life as one of the key influencing factors over which device they will purchase.

If the battery life of an IoT device fails to live up to its expectation, the impact can be widespread. It can negatively affect a product maker’s brand, and lead to increased customer dissatisfaction and decreased sales. If the battery life issue is significant, it can even result in a costly recall. Because of that, long battery life is now considered key to an IoT product maker's economic viability. In life- and safety-critical IoT devices for military, emergency response, and implanted medical applications, it's essential.

Fortunately, there are a number of steps IoT device developers and manufacturers can take to optimize battery life. One of the most crucial steps is just using the right test equipment. Here’s a few things to look for when making that selection:

Tip 1: Use an instrument with sufficient dynamic range and precision. By their nature, IoT devices have very dynamic current. They have sleep or hibernate modes in nA or μA range, and transmit modes measuring mA or A. If you want to be able to measure these low currents accurately and then quickly switch to measuring high currents, you need to use a measurement instrument with either dual ranges or a seamless ranging capability. It is the only way to avoid the errors that come from range changing.

Tip 2. Make sure the instrument has sufficient bandwidth. If you use an instrument with insufficient bandwidth, you risk severely degrading your current measurements. Worse yet, you can potentially miss measuring the fast transients that briefly draw an amp or more and then go away. Missing just one transient can be the error that makes your device fail prematurely.

Tip 3. Use an instrument that enables you to accurately simulate actual user environments. No matter how much battery life testing you do, you can only simulate so much in your lab. Real users behave differently than you would expect, and the context in which they do varies constantly, especially as people and smart vehicles enter and exit the device's area of operation. Every retry of a failed transmission drains your device’s battery a bit more.

To make sure your IoT device is ready for these sub-optimal conditions you need to test in real environments, but it's an expensive and time-consuming proposition. You can get the information you need; however, by using an instrument that faithfully simulates real-world environments like crowded office buildings and hospitals. By being able to test your device in these challenging electromagnetic environments, you can quickly validate its functionality without the high cost that's normally associated with field testing.

If you are an IoT device developer or manufacturer, finding ways to ensure your device’s battery life is optimized for the real world should be a chief concern. Selecting the right instrument with which to make your measurements can go a long way in helping you reach that goal, but it’s only a start. For more tips on what you can do to optimize the battery life in your IoT devices, check out the Battery Life IS IoT Device Life infographic at www.keysight.com/find/devtestiot.