I guess manufacturers could embed the protection circuit in one of the terminals but that’s expensive so surprise surprise no one does it.
Battery OEMs don’t do it, but adding a protection circuit to the end is extremely common in the flashlight industry. Ideally, the springs in the battery compartment provide some flexibility about battery length so both bare and protected cells work.
Battery OEMs don’t do it, but adding a protection circuit to the end is extremely common in the flashlight industry. Ideally, the springs in the battery compartment provide some flexibility about battery length so both bare and protected cells work.