Water damage (vertical lines) what do i replace

[Lidwien]

Fairphone 4 fell into the sea

Have a look at the waterwiki Anyway you shouldn’t use the swollen battery anymore for security reasons. You might check if there’s a fairphoneangel near you. So you might check the phones functionality before ordering a new battery.

You don’t seem to have a swollen battery, But you could benefit from the other topic.