The battery in my old phone has swollen up like a pillow — I'm half expecting it to explode.

What does The battery in my old phone has swollen up like a pillow — I'm half expecting it to explode. mean?

The battery in my old phone has swollen up like a pillow — I'm half expecting it to explode.

The battery in my old phone has swollen up like a pillow — I'm half expecting it to explode. in other languages