how bad is "hey cortana" feature on battery life?

[Modification]

Location Services are transactional and use very little battery...

I don't know too much about the specific details behind location services and Cortana herself but there are several threads and articles on the web that shows some relation between Cortana and battery use. These resources, however, pertain to smart phones and not the surface pro 3 so it's not exactly a direct correlation.

 

[jnjroach]

I don't know too much about the specific details behind location services and Cortana herself but there are several threads and articles on the web that shows some relation between Cortana and battery use. These resources, however, pertain to smart phones and not the surface pro 3 so it's not exactly a direct correlation.

Yes, those related to Phone and most related to the early Beta of Cortana during the Phone 8.1 Preview and now with the re-working of Cortana in Windows 10.

 

[sharpuser]

Hey, Cortana...
How much battery life do I have?

Eats up a bit more.