not parent but Garmin has many solar watches, some of them could be used indefinitely without ever being recharged, depending on your lifestyle and how much tim

not parent but Garmin has many solar watches, some of them could be used indefinitely without ever being recharged, depending on your lifestyle and how much time you spend out in the sun, e.g. https://www.garmin.com/en-US/p/775697 https://www.garmin.com/en-US/p/775697 But in other solar models, the energy consumption is greater than the energy produced, so the solar charging feature is just a way to extend battery life. In that case you will have an indication of how long the battery lasts, for example in this model it lasts 2 weeks https://www.garmin.com/en-US/p/702902 https://www.garmin.com/en-US/p/702902