If my math is right, 5.5 W means you could power this chip from a pair of high-end rechargable AA:s for about an hour. That's pretty cool, for something with this level of performance.
I assumed 2400 mAh cells at 1.2 V; two in series gives 2.4 V, powering a 5.5 W load at 2.4 V requires a current of 2.3 A which said cells should be able to deliver for one hour (2300 mAh).
Of course, this skips any contemplation of what voltage the chip actually wants, which is probably lower than 2.4 V, and thus means some conversion (with losses, etc) needs to happen.
I assumed 2400 mAh cells at 1.2 V; two in series gives 2.4 V, powering a 5.5 W load at 2.4 V requires a current of 2.3 A which said cells should be able to deliver for one hour (2300 mAh).
Of course, this skips any contemplation of what voltage the chip actually wants, which is probably lower than 2.4 V, and thus means some conversion (with losses, etc) needs to happen.