🔋 Vivo Y100: Why is my phone battery draining overnight?

My Vivo Y100 battery drains a large amount overnight even with the phone left completely idle on the nightstand. It loses around 15 percent while just sitting there with no apps running in the background. Battery usage stats do not show anything unusual. What could be causing this drain?

A 15% overnight drain on a Vivo Y100 is higher than expected and can be caused by poor mobile signal, background system activity, location services, or battery health. Try these steps: • Check whether the phone has weak mobile signal overnight; poor reception can make the phone work harder to maintain connectivity. • Temporarily enable Airplane Mode overnight and compare the battery loss. • Turn off Bluetooth, GPS/location, and hotspot before sleeping. • Check for pending system updates and restart the phone. • Try Battery Saver overnight and compare the results. If the drain remains around 15% even in Airplane Mode with the screen off, the battery itself may be degraded and should be tested by a technician.