To replace an HP laptop battery that doesn't charge, remove the battery, identify the product number of the laptop, purchase a new battery, and snap it into the battery slot. Before starting, make sure the laptop is shut down completely so the operating system is not harmed.
Flip the laptop over, and locate the battery enclosure on the bottom. Press the battery release button or slide ,and hold the release latch to the unlock position. This allows the battery to slide out of the clamp. Alternately, use a finger to lift the battery up and out, and unsnap the battery cover from the battery.
Purchasing an appropriate replacement battery is important, since each model of laptop requires a different one. Before buying a replacement battery, identify the product number of the laptop, and check the back of the old battery to determine which replacement model you need. Batteries of many different sizes are available. Typically, the size of a battery determines the number of hours it lasts after charging.
Insert the new battery into the battery slot. The battery should slide into place and firmly fit into position. If the battery fits into the base enclosure, it produces a click. Snap the battery cover onto the new battery. Charge the battery until it is at 100 percent before turning on the laptop.