The Ridgid Tool Co., founded in 1923, produces professional tools, including power drills, many powered by 18-volt lithium-ion (Li-ion) battery packs. Li-ion battery packs have gradually replaced nickel-based battery packs because Li-ion is more powerful, weighs about 40 percent less and holds a charge longer. If you find your Ridgid 18-volt battery pack begins to lose its charge quickly, or you notice a lack of power, it can be caused by shorting in one or more of the Li-ion cells in the battery pack. Try fixing the drill battery before buying a new one.
Remove the cover from the 18-volt Ridgid drill battery. You will find it's held in place by up to eight Phillips screws, depending on the type of drill battery. Remove the screws using a suitably sized Phillips screwdriver, then gently lift the cover. You can't completely remove the cover because there are wires from the battery cell connected to the terminals on the battery cover. You can see the Li-ion cells inside the battery case once you have put the cover to one side.
Lift the complete 18-volt Ridgid cell pack from the battery case. You may need to remove any screws holding the bottom plate in place. You can access the Li-ion cells once the cell pack is removed. The cells are soldered to metal plates and are wired in series. Each cell produces 3.6 volts, so there are five cells in the pack and 10 soldered connections.
Heat a soldering iron. You need to melt the solder between each cell terminal and the metal plate. This fixes bad connections.
Put the end of the soldering iron directly onto a metal plate immediately above a cell terminal. Look between the metal plate and the cells and you can see the soldered connection. Wait while the solder melts. Remove the soldering iron. Use the end of a flathead screwdriver to carefully put a little pressure on the metal plate on the same place as the end of the soldering was placed. Let the solder harden (a matter of seconds), then remove the screwdriver.
Repeat the process on the remaining nine connections, using the soldering iron to melt the connections between the cell terminal and the metal plate. Apply a little pressure on the metal plate using the screwdriver while the solder hardens on each connection.
Let the cell pack cool completely. Replace the five cells into the battery case and screw the bottom plate back into place, if it was held this way.
Replace the battery pack cover. Use a Phillips screwdriver to tighten the screws that hold the battery cover in place. Put your 18-volt Ridgid battery pack on charge. Replace the battery pack in the Ridgid drill tool once charged. You should find the battery is fixed, so you won't need to get a replacement.