How Many Amps can I safely get from the 12V receptacles?

I am a new TM owner, and am about to venture out on our first trip. Thanks to information I have read from everyone on the board I feel reasonably well prepared. I do have one questions I can't find the answer to. I purchased a 12V coffee pot and as soon as I plug it in, it blows the standard 7.5 amp fuse that is in the power panel to power the 12V receptacle. The coffee pot has a seperate 20 amp fuze, so I guess that it is just drawing too much power from the socket. Does anyone know if it is safe to increase the size of the fuze on the 12V circuits. I found a reference in the Power Panel manual that says the power panel itself should be OK with a 20 amp fuze, but I doubt the 12V receptacle would be (or they would have fuzed it that was from the factory). Assuming I am stuck with 7.5 amps, has anyone found a way to get more amps to the 12V receptacles? Thanks in advance for any answers. Cofee pot or not, I'm off to Joshua Tree National Park tomorrow for New Years - can't wait for our first TM experience.