That's going to be a major hurdle for adoption among a wider audience. Not that they need it to be successful, by the way. But most people already end up charging their mobile phones everyday, then they'll have to keep remembering to charge the watch as well every week... that's not very user friendly.

If the battery lasted one month, that would probably be a good spot to be at.

I wonder if they could make an e-ink display with a layer acting as a solar panel charger at the same time. Maybe they could recharge the watch this way, continuously.