CMOS batteries in iLive racks?

I have a question about what types of iLive devices have CMOS batteries. I know that the touchscreen computers in the surfaces have them (and I’ve changed a couple), but if I go to the Date/Time screen on a surface I see a separate date/time listed for each component (the touchscreen, the surface, the mix rack, and in my case the xDR-16 expander). That would seem to suggest that each one has its own clock (and thus presumably its own battery). However, the one xDR-16 I’ve had open I never saw a battery, and I’ve never seen a thread referencing changing batteries in anything except the touchscreen computer.

So can anyone confirm if iLive components besides the touchscreen computer have a battery? If so, any guidance on where inside those batteries are?

Thanks.

if I remember correctly, racks (mix-racks and expanders) have no batteries

The mix racks have a rechargeable battery soldered into the main board. I have my IDR48 apart at the moment to give it a service. the battery is the green thing on the bottom right.