Removing a Black and Decker lithium battery is a simple process that can be done in just a few minutes. First, locate the battery release button on the bottom of the device. Press and hold this button down while simultaneously sliding the battery out of the battery compartment. If the battery is stuck, you may need to use a flathead screwdriver to gently pry it loose. Once the battery is out, simply unplug the power cord from the device and dispose of the battery properly.