I am not satisfied with battery life.

I am using non-rechargeable batteries. 

An Xbus Master plus five MTx units or more has a significant power demand.  Xsens is providing high capacity rechargeable batteries designed for industrial use with the Xbus and Moven systems because of their performance and endurance. Xsens recommends using this type of batteries for best results. When recharging the batteries, select a slow charging mode to ensure maximum endurance. When performance decreases over time, use a refresh mode, if your charger features such functionality. 

Tests have shown that alkaline batteries perform far worse at high currents than recharchable batteries. In particular, the voltage drops faster than with NiMH type batteries.