ADC for higher voltages than VCC?

[Nick]

So i am using a LiPo battery at 4.2V and running my nRF51822 at 2.0V. Is it safe to connect the battery to one of the I/O pins to read off the battery voltage (as to calculate battery percentage)?

Much Thanks!

[Ole Morten]

Have you had a look at this question?

[Bastiaan]

Much Thanks, Did not see that.