rain cannot damage the solar panels but i had one panel broken with heavy hail .
Valve-regulated lead acid car battery , all they need is a bit of cleaning and such .. the battery can last betwen 55 to 60 months ( and more in case of moderate usage )
each 3 month i shake the batteries a bit and clean them from corrosion ..you can have hydrogen build up with these batteries so ventilation is extremely important
also these batteries doesnt play well in extreme heat or cold .