thank you very much for the graph tpetar! but what do you mean with the shottky diodes? - i was planning to use the voltage regulator in order to stabilize the voltage(to avoid ripple and such, ofcause with a good cap aswell). crutschow the battery is labeld as 1200mAh, but its a cheap chineese one, so i guess 900-1000. for the current consumption i cant really tell since its a very dynamic system with sleep modes and on. However i predict the average draw would be in the range of 150mA. After posting this thread i decided to meassure it for myself, so im currently discharging the battery and meassureing the voltage drop over time. ill post the results when im done