The only way to determine for certain that you can make it through a weekend at anchor without charging capabilities is to add up the maximum current draw of each accessory you are running. Since none of the things you list will likely run continuously, you can factor the approximate run time into the calculation. Once you come up with an AHr (amp/hr) number you will look at the label on the battery and see if there is enough capacity. There is no such thing as an "average" deep cycle battery. Deep cycle batteries are rated in either AHr or Reserve Capacity. Reserve capacity is an industry standard and uses a 23 or 25 amp current draw to come up with reserve capacity called reserve minutes. If the label on your battery says 175 minutes, that means the battery can supply 23 or 25 amps continuous for 175 minutes. Hopefully your load will be nowhere near that so if you used a 5 amp continuous load, the battery could supply 5 amps for five times the 175 minutes which would come out to 14.5 hours of continuous operation. Still not enough for a weekend but again, you should not have a continuous 5 amp load during the day, but it would likely be more than that at night. Unless you have a sizable boat, you need a fairly large capacity solar panel to keep the battery charged.Same for wind power. If your boat is an I/O or has a big outboard with high output alternator you could charge the deep cycle from it via a dual battery switch or ACR.
