Are any of the units of any use in/after an EMP or do the individual components need special protection?
Is it safe to put the BLUETTI battery in an EMP bag? Can it get damaged enclosed in the bag?
I debated if the batteries need protection but have decided they do as there are electronics built in.
If you are worried about HEMP (High Altitude Nuke EMP), they will be fine. HEMP is not an issue.
If you think you might be in range of a HPM-EMP (High Powered Microwave) (non-nuclear, but RF), then your results may vary. The BMS may become toast after a HPM-EMP, and with it (usually) permanently connected to the battery, there is no way to "power it down" to keep it better protected. Low probability of ever being in an area of a HPM-EMP attack, but technically possible with plane and missile based systems now.
I have plenty of LiFePO4 batteries, and since the BMS systems in each are IMPORTANT for safety and normal operation, I have bought spares (and for more probable reasons that HPM-EMP).