Potential for a solar panel under the transparent back cover?

[Stefan]

@kuleszdl

Another point not mentioned here is the impact of the battery health. If you consider a situation, where sun is once there and then it’s away, you will get tons of charge/discharge cycles which could considerable shorten the lifetime of the battery.

This is not true. One charging cycle is from 0%-100%, so if you have 100 partial charges of 1% you get 1 full charging cycle.

@techinsider.io

Charging your phone when it loses 10% of its charge would be the best-case scenario, according to Battery University. Obviously, that’s not practical for most people, so just plug in your smartphone whenever you can. It’s fine to plug and unplug it multiple times a day.

[Source]

Battery University seems like a trusted source, more info here: Battery - how to treat to expand lifetime (Optimal Charging Tips) - #22 by Ed_Bycroft

So, in conclusion, the discontinuous charges of a solar panel would not do the battery any harm.