The inverter that groo is refering to is used with a 12 volt battery and does not require an engine to be running. The Honda inverter generators need to have the generator running to make the inverter work. The honda EU series of gen sets are very good, quiet, fuel effencient, long life (some of the RV crowd claim 10k hours), and very clean power. The inverter gen sets are also expensive when you compare it to a common generator of the same size.

If you want to know more about the honda inverter sets try here,

http://autos.groups.yahoo.com/group/Honda_EU2000_Generators/