My friend was thrilled to have his first wireless mouse for his computer. A wireless mouse felt like the end of a prison sentence, where one can walk and work freely without restrictions. He could now mouse freely without feeling tethered to the laptop. However, the cost of replacing the mouse batteries started to have an impact on his pocket. He turned to engineering for help.
After studying the mouse, he discovered that the mouse which was powered by two AA size batteries could accept a power input of 3-6 Volts. He devised a clever plot where he could get 5V power from one of the extra USB ports of his computer. Being an electronics guru, he did the wiring and soldiering and within a short time, his problem of always replacing batteries on his wireless mouse was solved. This is the product he ended up with.
He is planning to patent the invention