That means your batteries are starting to get low and should probably last for a few more weeks.
We advise to get new batteries when this indication appears to ensure proper operation and functionality of your Sensibo. Each Pod requires 2 2/3 (CR123) batteries that can be found in photography stores, general stores and online.
Pods can operate on low batteries for varying periods of time depending on usage and the environment of each Pod (the strength of the signal between the Hub and Pod that can be weaker due to other transmitting devices around them).
Once you replace the batteries in your Pod, this indication will disappear.