Bikers want to charge their devices containing batteries (such as smart phones, bicycle headlight, head cameras), which they need in their daily lives, with the energy produced by their bicycles. A device capable of storing kinetic energy of bikers contributes to environment friendly electric power generation. This paper presents a multiple output battery charging circuit design for bikers. Proposed design consists of a dynamo capable of producing 12 V and it charges 2x 4000 mAh storage batteries with a buck converter that produces an output voltage of 1.29A 4.2V. Li-ion batteries are the most suitable batteries for portable storage applications due to their compact size, light weight and long-life time features. 2x 4000 mAh Li-ion batteries charge a 5V 2000mAh battery with a boost converter. Proposed method is simulated using MATLAB/Simulink. The simulation results are compared with the experimental results. The simulation and experimental results are in accordance to each other. A biker using the device suggested in the study will be able to ride an average of 2 hours a day and store the energy to fully charge the smart phone or bike headlight or head camera with 1 week of use.