Ryobi cordless tools all come with a rechargeable battery pack. Much like every rechargeable battery, your Ryobi drill battery pack will eventually lose its charge. If you do not want to buy a new battery pack, you can replace the cells inside your battery pack. This involves dismantling your Ryobi battery pack, and detaching the cells from the battery pack’s casing. Doing this yourself will void your Ryobi power tool’s service warranty.
Press on the release buttons on each side of the battery pack to remove it from your Ryobi power tool or Ryobi RB18L50 battery charging unit.
Loosen the Phillips-head screws from the battery pack’s outer casing. If there are no screws, cut open the battery pack with a soldering gun.
Attach a chisel tip to your soldering gun. Plug in your soldering gun’s power cable to the nearest electrical outlet and allow the tip to heat for about five to 10 minutes.
Locate the crease along the outside edge of the battery pack’s casing. Press the heated chisel tip to the crease. Firmly run the chisel tip along the outside edge of the battery pack, while cutting through the plastic casing. Allow the casing’s melted plastic to cool for a few minutes.
Lift the top of the battery pack’s casing from the base of the Ryobi power tool battery pack to reveal the cells. Examine each of the battery cells, and how they are connected. Touch the heated soldering tip to each of the connectors on the battery cells to disconnect the cells from their individual connectors. Remove the cells from the battery casing.
Cordless Drill Battery, Power Tool Battery 
A cordless drill is a good tool for the job. get your battery hear.