Using the DeWalt DCB205-2CK battery starter kit is easy. First, take the batteries out of the tool bag. Insert a battery into your 20V MAX* tool. The 3-LED fuel gauge on the battery will show you how much charge is left. When the battery runs low, use the charger to recharge it. Just connect the battery to the charger and plug the charger into a power outlet. For maintenance, keep the batteries and charger in a dry place. Avoid exposing them to extreme heat or cold. Also, don't overcharge the batteries. If you're not using the kit for a long time, it's a good idea to charge the batteries every few months to keep them in good condition.