Craftsman is the brand name for a comprehensive range of manual work equipment, including a line of battery-operated power tools. The more powerful cordless tools operate use a 19.2-volt battery pack. Recent Craftsman battery packs contain nickel metal hydride (NiMH) cells, which are increasingly replacing nickel cadmium (NiCad), as they are more durable and not as susceptible to the commonly used term "memory effect." This is when a battery appears fully charged, but may only be halfway charged. It occurs if a battery is not fully discharged on a regular basis. If this happens, there's a simple procedure to restore your Craftsman battery.
Put your Craftsman 19.2-volt battery pack in the charger. Allow it to charge until full. On some models, a light illuminates when full; on others, a light is on during charging and turns off when charged.
Remove the Craftsman battery pack from the charger. Insert the battery into your device.
Turn your device on and let it run at the slowest possible setting. You need to discharge the battery as slowly as possible. Allow it to run until it stops working.
Remove the battery from the device. Leave for 10 minutes then replace the battery pack in the device.
Turn on your device. It will run slowly, so let it operate until it stops.
Repeat the process by removing the battery, letting it rest, then putting it back into the device. Do this until the device does not operate. Your Craftsman battery is fully discharged. Let the battery rest for up to an hour to cool down.
Put your battery in the charging unit. Leave it to fully charge. This takes considerably longer than you are used to. Once it's fully charged, remove from the charger. Your battery should be restored to full capacity.
Don't leave battery packs in a charger once charged. It exacerbates the so-called "memory effect." Fully discharge your battery regularly using the above steps: once a month is good. This keeps your battery in top condition, and should ensure you get at least 500 full charges before it needs rebuilding or replacing. You can use the same procedure if your battery pack contains NiMH cells. NiMH batteries can suffer from voltage depletion which gives a similar effect to that of NiCad batteries, but it occurs less often. To prevent voltage depletion occasionally (every two to three months, depending on usage) completely discharge your NiMH battery then fully recharge it. Check the type of cells contained in your battery pack by reading the label on the battery pack. It clearly says NiCad or NiMH.