Abstract: Extending the battery lifetime is very important in battery operated systems.Considering energy consumption and battery state as a whole,we depict the discharging behavior as a Markov process,then build a two-goal optimal system model and propose a battery state aware adaptive voltage adjustment method called BSAAVA,which first obtains the operations in binary tree-based way,and then allocates the idle time in an optimal rule.Experimental results show that it achieves much improvement on battery lifetime over the current methods.