For some use cases, reliance on a phone is sub-optimal. Multi-day wilderness bikepacking, ultra distance racing, etc -- phones just use too much power when you can't get a few hours of charging every day or two.

Only a day? COROS has it beat by having 100+ hours of GPS riding.

And I think GPS is the key power consumption part here. Have you tried opening one of those background location tracking apps that would require your phone to receive GPS all day long? That significantly reduces battery life on your phone. You really want your entire GPS stack running on a power-sipping processor, not on your phone’s application processor.

> and they don't seem to suffer from display scaling since the larger Edge 1050 runs for even longer

Why would they suffer from display scaling? At the same device thickness, larger devices have the same volume per cm² of display. And it gets better:

- if they need the same volume for electronics (likely mostly true; you may want a slightly faster CPU and more memory, but don’t need a larger GPS, second WiFi chip, etc), that means more battery volume per cm² of display.

- at small sizes, I guess/expect wall thickness of the case to scale slower than the dimensions of the case, giving larger cases relatively more internal room.

(Googling, I see the 550 is even slightly thicker than the 1050; 16,8mm vs 16,3mm)