The DGX lights include one of these generic battery and chargers, but any good quality protected-type 18650 battery and charger is suitable. They all pretty much work the same way and are interchangeable. Some batteries ship with a small adhesive cover on the ends or a sealed with a clear (not blue) plastic shrink wrap, if so remove and discard. Place the battery in the charger, matching the positive and negative indications on the sides of the battery to the same indications on the charger (the plus is on the end nearest the cord), and then plug in the charger. If the battery is properly positioned in the charger, a red light will illuminate and then some time later change color to green when done. Charging time varies considerably depending on the pre-existing charge level of the battery, typically 2 to 3 hours but can be as long as 4 to 6 hours for a depleted battery, and it's normal for batteries to get warm while charging. Best practice is never leave charging unattended then once the light turns green, unplug the charger and remove the battery.