Powering ID2 RFiD reader

I am using an ID2 RfiD reader and a blue Smirf as a serial over bluetooth conenction to stream the data to a PC. At present I have it breadboarded up and is running from 9V battery going through a 5V regulator to bring it down.

I really want to run this off as small a power source as possible, (ideally coin cells) I know that the bluesmirf will run on 3.3V and the ID2 needs 4.6V, I hav tried to use two 3v Coin cells but it does not provide enough juice :?:

Does anyone know how I can get this set up to run from coin cells (or a power source of equal size)

What is it that the 9v battery supplies that the coin cells are not capable of doing? (I am aware that may be a stupid question, but its something I dont have the answer too)

Hope someone can help me!!!

The 5V regulator probably requires at least 7V input to work properly. You could try an LDO regulator.

Leon