If your battery is not working you can remove it and replace it following the step by step process. The battery can easily just pop out following simple steps
Turn the device over so that the screen is facing down.
Using a hair dryer, slowly heat the edges of the WorkPad.
Spend at least one minute heating each side of the device. This will melt the glue holding the case together, and allow it to be removed.
Use a plastic opening tool to pry the back case from the WorkPad.
Remove the yellow tape that is covering the battery connector
Using the tweezers, carefully disconnect the battery cable from the port
Using the plastic opening tools, lift the battery out of the case