Development of a Mechanical Battery Texas A&M University - Kingsville Luis Muratalla – MEEN Senior Jonathan Boehm – CEEN Sophomore Gary Garcia & Richard Rivera – MEEN Sophomores Noe Cantu – EEEN Junior Nov. 30, 2009, College Station, TX Faculty Advisor – Dr. Larry Peel, Student Mentor – Firoz Ahmed

Project and Semester Objectives Design and fabricate a lightweight rechargeable mechanical battery. Store and convert potential energy to electrical energy using Fiber Reinforced Elastomer composite strips. Semester Objectives Complete Steel Frame Fabrication, Assemble all mechanical components, Test battery with prototype strips, and mechanical brake. Characterize component weights, generator output

Current Testing Platform

Carbon steel prototype -allows for an inexpensive and easy to modify test platform. Provides mounting for the strips to fully stretch more easily. Allows for longer strips (approximately 6.5 ft length) Longer strips increases energy density.

Gearing System Linear Design Gear Ratio Information  1:4 Ratio from Strip Shaft to Generator Crank Arm  manually tensions the composite strip shaft  Gear for composite strip shaft  Intermediate gear  Generator Gear

Braking System Prototype uses manual mechanical on/off brake Free moving hinge design Allows for composite strips to remain in tension Easily released with leverage. Final system will use an electro-mechanical brake.

Weight Budget Current prototype frame is carbon steel Prototype weight: lbs Projected weight of aluminum frame: lbs Weight saved using aluminum: lbs

Power Generation 12 VDC, 20 amp output Charge Batteries Power 12 volt DC equipment

Composite Strip Test Data

(in.)

Work To Come Complete electrical system Testing of single strip vs. three strips Analyze test results Attempt to refine design Test completed system

Conclusion The fabrication of the prototype frame and internal components are complete Material relaxation is an issue with the strips Likely will have much lower energy density than expected in the battery. Battery is best suited for high intensity low duration energy output.

Special Thanks TAMU Space Engineering Institute Magda Lagoudas Dr. Judith Jeevarajan NASA (Prime Grant No. NCC9-150) TEES (Project No C3) Texas A&M University – Kingsville TAMUK staff and faculty