I find that I get an amount of solar charge when I am riding. For example I gained 20 minutes in a 3 hour ride last week in rather variable conditions. This is probably useful.
However I get no noticeable charge with the unit powered off and left in the sun. This is odd as when I power off the screen it gives a reading of both the battery level and also the current solar power available together with a message saying to “face the screen into the sun” as it shuts down.
So it implies that the unit should change when powered down - but if I leave it in the sun for a few hours there is no increase in battery level.
Is this expected behaviour?
The solar function would be a lot more useful if it worked with the unit powered down.