BatteryBuy.us is specialized in providing high-quality replacement batteries for varieties of laptops. All COMPAQ PRESARIO CQ40 batteries that we supply will be tested by technicians to ensure that their designs can meet or even exceed OEM specifications. You can choose the correct COMPAQ PRESARIO CQ40 battery from the following directory. In addition, we also provide a 30-day refund guarantee and a one-year warranty to ensure your confidence with our COMPAQ PRESARIO CQ40 batteries. If you have any questions, please feel free to contact our customer service. It is our pleasure to solve problems for you.