Both inflated inside the machine!! Both the one that came with the machine and the one I bought a year later from Skroutz. And instead of the price dropping, I see it has gone up!

Only genuine batteries from the manufacturer of each machine!!! I insist on this and support it no matter what they tell me anymore! That is, batteries from third-party manufacturers cost 4 times less money but are only 10% less efficient compared to genuine ones!!! This is not a lie, but obviously no salesperson has tested them in real conditions. Having baptism in a seaside place in the heat, the machines work under the sun no matter how much you protect them.
2 Fujifilm X-T3 cameras on me, 1 DJI Mini 2 drone flying in the sun, 1 GoPro Hero 10 on a tripod for timelapse under the sun. In the bag under the thick shade of a tree, we had 1 Canon 5D for video with extra batteries, 2 more batteries for the drone, 4 more batteries for the GoPro, and 4 more batteries for me. 2 Fujifilm NP-W126S and 2 more from a third-party manufacturer. Out of all the batteries that were working under the sun and those that were in the bag under the shade, none of them suffered anything except for the 2 imitations of mine for the X-T3. They swelled up like cakes from the intense heat!!! It sounds funny and it was very funny. We burst into laughter just because I didn't have them inside the cameras to be destroyed and to look for machines to work with. If they swelled up so much in 2 hours under shade and without working, what would happen if I had them inside the cameras?!!!
You don't need to verify what I mean by "swelled up" !!! For me, my mistake became a lesson! Only genuine batteries in our machines!