These 510 threaded batteries are compatible with pre-filled or refillable cartridges. The Atman 380mAh battery, allows you to enjoy vaping all day before recharging. Adjust the voltage between 2.0 and 4.0V depending on the type of material you’re using in your cartridge. The 510-thread size is the most common, so it will fit with the majority of available carts. The USB provides a fast charge without requiring a wall block. For safety purposes and to prevent overheating the battery stops outputting power if the draw taken is too lengthy. To turn the device on, quickly press the button 5 times. Hold that same button down to draw. It’s personal preference whether you prefer to hold the button and heat up the material to get a massive hit or start drawing as soon as you press the button down for a more moderate hit. Preheat mode can be activated by rapidly clicking the button 2 times, this allows for the battery to continuously heat for 15 seconds. The device also has an auto-shutoff to prevent overheating. Variable voltage is achieved by simply twisting the bottom of the battery to desired temperature. The voltage range is between 2.0 and 4.0 volts. Remember, different viscosities will vaporize better at different temperatures. To charge the battery, screw on the charger the same way you would thread the cartridge. It is recommended to charge in a computer or a similar device. Sometimes using a wall adapter (especially a high powered one) can cause damage to the battery. The lights on the device and charger will be red while charging, and then turn off on the pen and change to green on the charger when complete.