If #battery drops below 15% notify via #pushover.

Create custom workflows effortlessly by selecting triggers, queries, and actions. With IFTTT, it's simple: “If this” trigger happens, “then that” action follows. Streamline tasks and save time with automated workflows that work for you.
5 triggers, queries, and actions
You can add delays, queries, and more actions in the next step!
A native Android service that lets you monitor a device's charging and battery status. This service requires the IFTTT app for Android.
Pushover makes it easy to send notifications to your Android, iOS, and Desktop devices from a variety of sources.