I'm pretty protective of my batteries, but one time my wife accidentally ran one to empty and now it's a $120 paperweight. Battery prices are a big sticking point for me as my budget is just a little too small to be ok spending so much on one, and this incident made me reconsider staying electric in the future.

Makita puts the protection/charge control circuitry in the battery pack, instead of in the tool or the charger. That makes their batteries more expensive, but you can't kill them by running them dry or through overheating in use. The pack itself will cut power to the tool. Makes them much more robust than the other common consumer/prosumer brands (not sure about pro brands like Hilti and Fein).

Though not uncommon this is simply a faulty product. Running them empty should not lock them out.

I left a battery on the charger for too long and it became a paperweight.

This kinda soured me on electric lawn equipment for a while.