@Wayne-TP 

Hi, 

this is also another scenario that the battery is not running low and stays always at %100 state for a while.. when battery gets %99 in cloudy day, solar panel charges it again and again.. so always stays at %100.. Lipo batteries needs to have drain and charge cycle rather than keeping them always at %100.  
Charging it fully, to 100%, stresses the battery. If you always charge to 100%, the battery will show some degradation after some 400 or 500 charge-discharge cycles. Its capacity will be reduced, and you will probably want to replace it with a new one.. you tp-link guys all know this technical thing, why you do not add a feature for this case , can't a firmware update and a software update solve this ? User perhaps can chose a charging cycle when "solar charging data" on on the app