Solar charger SLS 2200 A1Very cheap quality item, it came to me with broken DC plug, opening was tremendously hard (true guesswork), one mini switch fall as my victim at opening the case, but everything was taken cared in the end.
This device and similar are primarily a simple power bank which gets charged by your PC USB plug, the solar cell is just for an emergency and needs 18 hours of sunlight so to charge the battery.
If ever need to open one like this, heat first with a hot air gun the solar cell and start gently pulling it by not using extreme force.
Take the screws off.
Get an small spatula for grouting and unlock the plastic hooks by working fron outside to inside.
Good luck .. you will need it.