[Nyororin]

It really depends on the rice cooker - but it sounds like the one you have may just be really cheap and not at all decent. The standard amount of water required for a regular rice cooker is up to the first joint of your little finger above the rice - and half that for a pressurized cooker (as the water does not escape).

7 cups though is a LOT for even a regular household Japanese one. Most at up to 5 cups. There are 10 cup versions, for large families, but I`d say 5 is standard. Smaller ones for singles tend to be 3 cup.