Laptop Charger Adapter for HP Compaq Series 18.5V 4.9A 90W. Power-up your notebook with the 90 Watt AC Adapter. The AC adapter converts AC power to the DC power required by the computer. It lets you operate your system or charge your notebook’s battery from electrical power outlets. Offering 90 watts of power, this lightweight and easy-to-carry power adapter proves to be an optimized portable power source wherever you are at home, in remote office or on the road. For true simplicity, leave one AC Adapter at your desk and keep another in your carrying case for quick access.