I have been very happy with my Lezyne Super Pro, and I think there are even a few less expensive options with turn-by-turn directions as well. You can download custom offline maps for whatever area you plan to ride in, directly to the unit, which I believe allows you to not rely on the phone at all. The battery claims 26 hours (not that I’ve ever done a ride long enough to test that), connects to the computer easily, shares data with Strava if desired, and charges quickly.