The battery cover has some serious heft, no doubt for structural aid and durability.

Update: We got one of the actual shipping units post-teardown, and confirmed that the floppy battery cover attaches to the rest of the phone nice 'n' securely.

On the inside of the battery cover, we find an engraving commemorating the first supporters of Fairphone's grand vision: "This phone and you and 9635 people made fairphone possible."