Using your DeWalt 20V Max PowerStack battery pack is easy. First, make sure your DEWALT 20 - Volt tool is turned off. Then, firmly slide the battery onto the tool until it clicks into place. When you're done using the tool, switch it off and remove the battery. To check the charge level, simply press the button on the battery, and the 3 - LED fuel gauge will show you how much charge is left. For storage, keep the battery in a cool, dry place. Avoid exposing it to extreme temperatures or moisture. It's a good idea to charge the battery fully before long - term storage. When it comes to charging, use a DeWalt charger that is compatible with 20 - Volt MAX batteries. If you notice any issues with the battery, like reduced performance or unusual heating, contact DeWalt customer service. They offer a 90 - day money - back guarantee and a 3 - year free service contract, so you can use your battery with confidence.