What I was thinking too. When you took it apart did you make sure all the cables/wires were o.k. before you reassembled? Mike_Lu makes a good point there, was the battery working smoothly before the cleaning? Did you make sure to clean the battery terminals too? You may have gotten dust/debris on the contacts while cleaning. Have you ruled out the power adapter i.e. run the machine with the battery out of it completely? Have you tried giving it a "deep charge"? Run the machine on battery until it shuts down, then charge it overnight. If you've tried or ruled out all the above its probable the battery is gone and needs replacing.

Replace battery