When a wireless sensor node has to run with batteries for months it is really important to know which is the average power consumption. Standard AA batteries have about 2000 mAh (they can supply 1 mA for 2000 hours), msp430 (which maybe is the 16 bit microcontroller with lower power consumption) can draw from 0,3 uA in sleep mode to 4 mA in active mode, a radio chip like CC2420 draws about 20 mA in Transmition or Reception, reading from any kind of sensors could up to 6 mA. The worst case would be a power consumption of 30 mA, that will draw the entire battery in about 72 hours. That’s not good. It is mandatory to have an inteligent operating system adaptation that really manages power consumption and starts and stops devices only when needed. But is also really important, when prototyping a wireless sensing application to know exactly how much power will it draw. This is why at dexma we have developped DXNRG, used with dexCell framework, will help integrators to fine tune the application and optimize battery life. DXNRG is fully integrated in dexCell Stack, it takes care of how much time each device is used, information can be sent over the network or over the serial port. Using dexCell Server integration, it is really easy to know which is the average power comsumption of your applications, and predict in a more effective way batteries life.