In Battery Pack BP-50 (EOS 50/50E and resp. equal models) one can eighter mount 4x AA or one 2CR5. a sketch in manual is telling how to mount but i dont understand or its not working. Thanks UPDATE: SOLVED. sketch is wrong but arrows right. One must lift the central contact unit- see red dot also. it can/should be mounted to parkposition-not to get lost. red dots must be aligned otherwise not engaging. Full unit terribly lightweight with tiny 2CR5. its the cam with 1/4000 flashsynch and eye-control. QD- data back only til 2019!!! Grrrr
