i have a powershot sx1 is, and it only works on 4GB card
You should be able to use a larger, partitioned card. Use
STICK to install.
Since you're on Windows, you may need to use
WASP to be able to access the large partition on the card (when using a card reader).
and i would like to do some time lapse like a whole day's work of it, but 4GB is not enough, and the power is not enough.
You can buy an external power supply for the camera - either the original Canon or a compatible one.
Transferring files (and do other stuff) over USB is possible, see:
http://chdk.wikia.com/wiki/PTP_Extension