One the reasons why we both have Android phones (Samsung Galaxy S3) is that the batteries can be easily removed and replaced. I purchased 2 of these 2 pack
2300 mah batteries from Ebay which along with the originals, gives us a total of 6 batteries to share. A separate wall charger at the time was only $10.00.
I keep one extra battery in my EDC bag and my SO keeps an extra in her purse. The other 2 spares are kept at home.Like any battery collection, proper rotation and charging is key.
_________________________
Earth and sky, woods and fields, lakes and rivers, the mountain and the sea, are excellent schoolmasters, and teach some of us more than we can ever learn from books.
John Lubbock