Using this DeWalt starter kit is easy. First, connect the charger to a power source and then insert the battery into the charger. You'll see the LED fuel gauge on the battery. It shows you how much charge is left, so you know when it's time to recharge. When using the battery with your DeWalt 20V MAX* tools, just insert the battery into the tool as you normally would. For safety, always make sure the charger is unplugged when not in use. Don't expose the battery to extreme heat or cold. To maintain the battery's performance, recharge it when the fuel gauge shows a low charge. Also, clean the battery and charger contacts regularly with a dry cloth. This will keep them working well for a long time.