Does anyone have any experience of the swelling of lithium-ion battery packs? Attached are photos of one that came into the workshop recently. The first is still in its Macbook and is genuine Apple, although you can see how it has forced its way out and distorted the case. The second shows the battery pack removed. No exudate is apparent. I have heard it suggested that this is due to overcharging, but have not seen it before. A camera enthusiast friend says it is common with some brands of cameras, but not all.