With the KA-A30B B-Mount Hot Swap Plate for ARRI ALEXA SXT/LF/65 from SWIT, you will not need to switch off the camera when changing your battery.
The KA-A30B powers the ARRI ALEXA SXT/LF/65 camera at 28.8V (22-33.6V) by the rear contact pins, and when you remove the B-mount battery, the KA-A30B output regulates 28V to the camera for hot swapping.
The KA-A30B has 32Wh/3Ah battery cells inside, and with 200W constant high load, even after 1000 cycle times, the plate can ensure two minutes for hot swapping.
An LCD screen displays countdown seconds when changing the battery.
When the battery is removed, the screen will count down from 120 seconds; you just need to put on a new battery before it counts down to zero.
The new battery will then charge the hot swap plate, and the countdown seconds will go back to 120.