Not having to use a phone for navigation either is great too, as it's typically a sucker for battery.
Interestingly depends massively on the phone - my Sony will apparently do 50 hours of sat nav use if tweaked properly - I still had 88% battery left from full charge after just over 3 hours of driving using it for navigation the other day whereas my friend on an Samsung S24 or S25 was down to like 20%! doing the same route.
You can have it plugged in though.