Look on the coffeemaker or supplied literature and find out how many watts it uses. AMPS times VOLTS equals WATTS. For example, my 4 cup Mr. Coffeemaker uses 650 watts at 120 volts, it needs 5.4 amps HOUSEHOLD CURRENT (650 divided by 120). Trying to power this coffeemaker from a 12 volt battery, you need 54 amps of current (650 divided by 12). This far exceeds the capacity of the inverter. It will not work! What will work ? A coffeemaker that uses no more than 300 watts.
Absolutely! I used it for a medium sized sound system for some outdoor events I did. It powered that and my computer without a glitch. Self cooling fan works like a charm. Some cars have to be turned on before the signal goes to the 12v/cigarette lighter, though, so make sure.