Can I measure battery level without any external components nrf51

[Mikhail]

I want to undestand this. I can't see any examples with it. In the example ble_app_proximity I always received 100% level. If it possible, can anybody give a ADC config example for it? Thanks.

[endnode]

Read this.

[awneil]

And, in particular, note that comment that measuring the battery voltage may not give any useful indication of the remaining battery life!