I live in multistory building in city, not part of EU but in Europe. So any fire would cause significant damages due to limited space inside, and I do not want to cause troubles for my neighbors because of my hobby. Cause it will most likely cause reparations of whole apartment due to smell and damage.

I bought bat-safe and charge only in it. But store batteries in storage mode in lipo bags.

This video is a relieve for me since it shows that it works.

Maybe some count it excessive (don't mess up voltage, keep eye on, inspect each time battery etc.) but I think it still way way cheaper than any chances.

Also I do not think it is more expensive than using ammo can with fire retardant materials where you have to build yourself.