These RV coffee versus inverter size versus battery amp hours discussions always make me grin.
I fill a titanium drinking cup (left over from my backpacking days) with water: Place it directly on one of our RV's (lit) propane burners in the galley. Leave it there until the water boils in a few seconds. Take the cup of hot water over to the dinette, sit down, and dump in one envelope of Starbucks Veranda blend of blonde roast instant coffee.
Wala ... hot delicious coffee with no battery discharging, no fussing, no noise, no washing of anything afterwards (wipe out the cup with a paper towel for use next time), and ready in seconds.
(Ooooops ... I can't believe I used the word "instant".)
