You can set up a workflow trigger which will send a message when a beacon's battery level falls below a selected threshold.
All workflows will need to be created in console.
Navigate to Workflows > Add Workflow
General Tab
Workflow Name: Low Beacon Battery
Sites: select the Site(s) you want to utilize this workflow in, if you only have one site you can leave blank
Workflow Tab
Click Add
Trigger: Low Beacon Battery
Battery less than: select your desired %
Condition: select condition if wanted, this is not required
Click Save
Click THEN
Select the Action
Customize your action by filling in the required fields
Click Save