Ryobi manufactures a large range of portable tools powered by battery packs. Replacement battery packs can be expensive, often up to a third of the price of a new power tool. Before deciding to purchase a new Ryobi battery pack it sensible to try and fix it yourself as it's considerable cheaper and, depending on what's wrong, you may not need to spend any money at all. Use the steps in Section 1 and Section 2 to check for quick fixes your battery. If these don't, then use the steps in Section 3 to fix your Ryobi battery.
Check the Ryobi battery pack to find out the type of cells it has in it. The label on the battery pack clearly states the type of cells. If it says nickel cadmium (NiCad) or nickel metal hydride (NiMH) then continue to fix your Ryobi battery. If it says lithium ion or lithium polymer, then you need to get it fixed by a battery repair company as the battery packs contain sensitive power surge devices which if tampered with, could render your Ryobi battery dangerous.
Put your Ryobi battery into the charging unit. Turn on the charger and let it charge until full.
Turn off the charger and remove the battery. Let it rest and cool down.
Insert your Ryobi battery into the power tool. Turn on the power tool and allow it to run until it stops. You need to discharge your battery fully. NiCad, and to a lesser extent NiMH batteries need to be fully discharged fairly regularly as over time the crystals in the cells grow and this result in the cell not being able to retain enough power so you get voltage loss and your battery goes dead quickly. Discharging a battery fully breaks the crystals down and then they can retain more energy.
Turn off the Ryobi power tool once it stops running and allow the battery to cool for about 10 to 15 minutes. During this time, you find the battery recovers some power.
Turn on the Ryobi power tool and let it run until it stops, then leave it for 10 minutes. Repeat the process until it does not operate. This means the battery is fully discharged.
Put the battery into the charger and let it charge until full. Remove the battery from the charger and insert into the power tool. Turn it on. If you find it has more power and lasts longer, your Ryobi battery is fixed. If there's no improvement, you have dead cells in the battery pack that need replacing so use the steps in Section 3.
Charge your battery in the charger, then put your Ryobi battery pack on a work surface. Remove the battery cover. It's held in place using small Phillips screws so use a Phillips screwdriver and remove them. Lift off the battery cover. Remove the cells from the battery compartment. Insert a flathead screwdriver under each cell and pry the cells out. Line up the cells on the work surface.
Check each cell's voltage using a voltmeter. Good cells retain their charge; bad cells discharge quickly. Put the two sensors on the end of the wires from the voltmeter onto the first cell's terminals. The sensor on the end of the red wire goes to the positive terminal and the sensor on the end of the black wire goes to the negative terminal. The positive terminal is marked "+" and the negative terminal "-."
Read the voltmeter display. If it reads less than 1.1 volt, it needs replacing. If it reads between 1.1 and 1.2 volts, it's good so keep it. Repeat the test on each cell then get the number of replacement cells you need from an electrical socket.
Replace the existing good cells and the replacement cells into the battery compartment. Simply push them into place using your fingers. Replace the battery cover using the Phillips screws and screwdriver.
Put your Ryobi battery pack on charge. It won't take long: about half an hour is fine. This lets all the cells charge fully and equally. Put the battery into the power tool and you should find the battery is fixed.
Dispose of NiCad and NiMH cells using a battery recycling unit. Never dispose of them in regular trash. Check the Resources section for a link on battery recycling to learn more.