Resmed S9 Elite & SD card management

[SleepyWayne]

Hello, fairly new user here.
I have had my machine for 35 days and I am using SleepyHead & ResScan. I ran into the issue of >30 day old usage data getting doubled and found a workaround here viewtopic/t78611/Sleepyhead-setting-or- ... litch.html My usage hasn't crossed a DST change, so I don't know if that is a trigger. Thanks.

My S9 only keeps the good hi-res data for 7 days on the SD card. So, I have been uploading to my computer at least once a week. But, I am getting ready to travel for 11 days, with my S9 but without my home computer, and don't want to lose data. I have seen posts that imply I can use more than one SD card? Do I just insert an empty SD card in the S9 and let it run? Or do I need to do something special? Can I use one card for half my trip and a different card for the second half, then import both when I get home? Or can I copy my SD card data to a USB stick halfway through the trip?

Do I need to backup my SD cards somehow? I see that Sleepyhead has a backup routine built in for the S9.

[Pugsy]

Take a blank card and insert it in your machine. The machine takes care of formatting. Nothing else is needed to be done.
No need to do a bunch of backups or anything. You can use it the second half of the trip if you wish. Anytime before that 8th day when previous hi def data gets overwritten is fine.
Extremely simple. Just carry a blank SD card and insert it when you wish.
Import both cards when you get home to complete your data on your reports.