This paper presents a method for widening bandwidth by using non-uniform mass which use the concept of center of gravity. Piezoelectric acts as a tool to convert vibration energy to electrical energy. The displacement from the liquid movement plays a role to enhance the bandwidth as the beam bends. The bandwidth is widened 2 times higher compared without tip mass and 1.6 times increased than that of solid tip-mass. High viscosity and density will give a greater effect on the bandwidth at low volume compared to low properties of fluid. Rectangular container can resist the tension of liquid due to high viscosity and volume. The fluid-filled mass technique widened the bandwidth without reducing the harvested power.