Originally Posted by
sau54
The reason why I brought my laptop with me was because I intend to use it to do the tele-COVID test. This was before the mandatory COVID test was eliminated. I didn't want to take it out for security so I threw it inside my suitcase. I guess that may have been the reason for my bag being checked?
I suspect your laptop drew their interest--you're lucky they even allowed it to fly. There are very good reasons for the rule against checking lithium-ion batteries! They have killed a jetliner, fortunately not one with passengers. Baggage handling also can be rough for something like a laptop, not to mention that you'll get $0 compensation if it wanders off--airlines specifically disclaim any responsibility for that sort of stuff in checked baggage.
Lithium-ion cells can decide to fail spectacularly. Usually it's during charging but on occasion it's happened with no obvious trigger. As the cells age they can develop a fault that causes them to discharge through themselves--the internal resistance is low so this gets very hot and the heat accelerates things even further. If that happens in the passenger compartment people will see it and while the fire itself is almost impossible to extinguish it can be kept from spreading. Nobody will be containing it in the baggage compartment.