Leica CL

Without a battery, the mechanical shutter still works at every speed including B; you just lose the light meter. ^[1]

To take a meter reading, the shutter must be cocked and the film advance lever pulled out slightly from its rest position. ^[1]

The battery compartment sits under the take-up spool, behind the removable back; the manual recommends checking the battery before you change film. ^[1]