Lot of rain
Opening the slides is not as critical but it would be a good idea if for no other reason than to keep moisture out of the inside of the trailer. If you have slideout covers installed there shouldn't be much moisture on the slideout roof. A slideout cover will act the same as the main awning and hold some water after it rain so if you have it stored at home you could dry out the awning and slide cover after it rains.
The tent ends are much more critical for having them dry before they are stored. Mould and mildew will form quickly if they are left wet in storage.
Your slides do operate off the battery.
2010 Rockwood Roo 23SS
2009 Ford F-150 XLT SuperCrew with Max. Towing
2011 Rockwood Signature Ultra Lite 8293SS, 12K Equal-i-zer
2016 Ford F-250 XLT SuperCrew, 6.2L, 4x4, 6'9" bed, 3.73
2010 Rockwood Roo 23SS (2012 - 2014)
2009 Ford F-150 XLT SuperCrew, 5.4L, 4x4, 5'6" bed (2012 - 2016)