Refer to the manual that came with your drill. Cleaning the cordless drill battery contacts is a way to improve its performance as well. Batteries usually have two contacts (one negative and one hot). Some use three, but one is for the charger to sense the voltage during a charge. Use a clean rag and wipe away any dust or debris on all the contacts. Make sure that your cordless drill contacts are clean of any type of junk because this can affect the charge of the battery. Knowing that your cordless drill is the most convenient tool you can own, you can maximize your purchase by keeping the battery powered up and clean and this way your cordless drill will always be ready the next time you need to use it.