AUTHOR: Francesc Xavier Pastor, Beacon Product Manager
The most important concern for beacon deployers is how often they will have to provide new batteries to beacons. Even there is a minimum consumption unavoidable, these guidelines will help you lengthen the battery life. In summary, battery life depends on several aspects:
- Advertising interval –> affects to signal stability, i.e. detection capacity by devices
- Transmission Power –> affects to expected distance range
- Number of advertising frames enabled
- Beacon placement
- Environmental conditions
This list outlines the major aspects of configuring a beacon properly and discusses key steps for each one.
1. Choose the advertising interval accordingly to your case
The advertising interval defines how often beacons say “Hey! I’m here”. Therefore, the more often advertises, the quicker is the beacon detected by nearby devices. For most use cases an advertising interval between 800 and 1000ms is enough. Upper than that (>1000ms) is not strongly recommended except for the telemetry which is not usually needed constantly. However, for use cases where the device moves all the time, such as indoor positioning system (IPS), an advertising interval between 100 and 400ms is recommended. Within this range, choosing a specific value will depend on the device speed and the accuracy needed for positioning.
2. Choose the transmission power accordingly to your case
Similar to what’s been explained for the advertising interval may apply here. You should wonder first which distance range is necessary for your case. For distances between 30 and 50m, -8dBm or -12dBm TX Power is enough with a difference of durability around 3 months over 5 years (being -12dBm the one with longer battery life).
3. Choose the proper frame accordingly to your case
Depending on how many frames are advertising at the same time, the battery will last more or less time. Therefore, it is very important to know exactly the target of your application. For example, if your case is thought just for Android users, you could use an iBeacon or Eddystone UID frames to interact with your app. In case you also wish to broadcast a website URL, we strongly recommend using the Nearby Notifications. You have to set up an URL notification associated to the iBeacon or Eddystone UID frame (previously registered) that you are using to interact with your app. Another example: both iBeacon and Eddystone protocols are able to broadcast the battery level. In the Eddystone case through Telemetry frame other information is broadcasted, such as temperature, elapsed time since the last power-up and number of frames advertised since the last power-up. In case your application just requires the battery level and the frame needed is an UID, we recommend using iBeacon frame with the extra byte enabled rather than enabling iBeacon or Eddystone UID plus Eddystone Telemetry.
4. Beacon Placement
Despite the fact that the beacon radiation is omnidirectional, a better performance can be achieved if it is placed in a medium high of the expected coverage range (one meter up onwards from the floor), instead of almost on the floor.
5. Other configuration tricks
There are other configuration features which may help you to save battery. For example, you can save a 30% of battery on average just setting the beacon in the “No Connectable” mode.
6. Environmental Conditions
The environmental conditions make beacon performance be changeable, depending on where it’s placed. Obviously, the conditions are different if the beacon is placed indoor or outdoor specially for the coverage area. Therefore, we strongly recommend to test beacons in the place where it will be installed or in one with the most similar environmental conditions to set up the proper TX Power and Advertising interval.
Conclusions In conclusion, you can lengthen the battery life of your beacons by just:
- Analysing deeply what you really need for your use case
- Testing beacons under real environmental conditions before deployment.