We all know Android OS switches off services one by one when the battery reaches critical level. But is there any fixed battery level to cut down individual services. For example, Bluetooth will be switched off at 20%, Mobile data at 15%, Wifi at 10%, etc. I am searching these information in Android documentation and Googling as well. But I am not able to find such information. Any help please.
"Services" doesn't mean what you think it means. A service is an app component that can run in the background. For example, an email app might have a service that's started every 15 minutes to check for new email (and stops itself when it completes). This means it's background apps that stop, not things like the Wi-Fi and mobile data.
App developers are encouraged to check for the low battery condition and stop battery-draining activities. This broadcast also triggers the "low battery" dialog, so it's easy to tell at what level it fires. It can be changed by the device manufacturer (since Android is open-source), but it's usually set to trigger at 15%.