"watts" divided-by "12 volts" gives amps. You're almost certainly looking at at least 15A (200 watts), and you'll need *BIG* wire and an upgraded 12V connector to support that load. The Wineguard connectors (standard equipment in TM) won't take it, their internal fuses will blow.
"Real" 120V coffee makers typically run around 800-1500 watts. So this 200-500 watt device will also heat water very slowly. You can use a "French Press" instead, with better results. But even better than that, here's a
great alternative idea for your morning coffee while boondocking:
- - - - Rickst29's "Better Method" Cowboy Coffee - - - -
Real Cowboy coffee, of course, wraps up the coffee in a paper towel or dish rag, usually leaking grounds when you make it. (And I hate that extra "crunch" in my morning coffee.) If you don't want to use a press pot, get a "Mr. Coffee"-shaped permanent filter (flat bottom, not the Melita style cone-shaped). Boil a thermos-bottle worth of water in a saucepan, or even a frying pan, on the stove. You need to use a big enough pan that the height of the water won't QUITE reach the top edge of the filter. About 1-1/2" of water height is perfect. When the water reaches boiling, turn the heat down a bit (boiling is too hot for making coffee at less than 9000 ft). And then set down your filter into the pan (with fresh-ground coffee already in it, of course).
Grab the edge of the filter, or the handle if it has one, and swish it around in the water for about 40 seconds. Pull out the filter, pour the pot of coffee into a nice thermos, done.
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I think that this is better than a "french press", because you can keep the water at high temperature through the brewing. In a glass press pot with no burner to keep it hot, the water and grounds almost instantly become too cold to do a decent job.