Can GivEnergy Solar batteries be installed outside?

Yes, as long as you have a cover over it.  GivEnergy equipment is IP65 rated, meaning it’s OK to be sited outdoors.  It must be installed out of direct sunlight and should also have a cover or canopy to keep the worst of the rain off of it.  Bear in mind that Lithium batteries perform best around room temperature so you’ll also see a drop off in performance and efficiency on colder days.