I dont think you can get Cr2s in protected.
Ive used them for quite a while and I have no problems with them. just dont leave in charger. Take them out when light turns green. You'll lose vape long before they are too low to dischanrge to critical level.
Just be careful in the charger and do not overcharge.
I don't fear using them.
Just be careful.
Ill let everyone know if I explode.. lol