I'm looking to deploy XBee modules, reading one input, waking every 30 minutes to transmit status. What sort of batteries are others using in this application. 3.0V lithium or 2 x 1.5V alkaline seem appropriate. That way I can eliminate the need for a voltage regulator.
However I see the Digi adaptors use 3.6V lithium batteries. Why is that and how do they drop the voltage to the maximum 3.4V supply of the XBee module? They need to do this very efficiently, without wasting energy?
Any real world experiences welcomed.