The Royal Supply 1300mAh Variable Voltage Large Capacity Batteries are perfect for the heavy user that needs a reliable device for extended use. This battery has an adjustable voltage dial at the base that allows you to adjust voltage according to your specific needs ranging from 3.3V – 4.8V. With a 510 thread, this battery fits all universal 510 thread cartridges. It also comes with three important safety protections: Short Circuit Protection, Atomizer Protection, and Low Voltage Protection. The battery can last up to 16 hours on a single charge. Technical Specifications: • Battery Capacity: 1300mAh • Variable Voltage Setting: Adjustable Dial, 3.3V – 4.8V • Charger: Wired USB Charger • Threading: 510 thread • Voltage : 3.3v-4.8v ( 4 voltage markings : 3.3v , 3.8v , 4.3v , 4.8v ) • Sensitive voltage steps : 0.5V • Power circuit : 9W • Working time : 14-16 hours / charge • USB charger included with each battery Features: • LED Light Indicator – The battery LED will blink when switching modes. • Low Battery Indicator – The LED will blink 5 times indicating that a charge is need. • Short circuit protection – When short circuit happens, the battery will shut down and not function again until short circuit is removed. • 5-click On/Off lock feature; Press the button 5 clicks within 2 seconds and activate the battery or turn it off. • A fully charged 1300mAh variable voltage battery can provide 14-16 hours of use. • Using the battery at a higher voltage output will drain the battery faster than at a lower voltage. We suggest you to start with a low voltage and increase the voltage gradually until you find the right voltage. • Safety Cutoff – If you press the button for 10 seconds, the battery will be locked until the next press. • Low Voltage Protection – When the battery voltage is lower than 3.3v, the battery will shut down. The LED will blink 5 times indicating that a charge is need. • The device will monitor the battery voltage and automatically turn off when the battery is discharged, preventing damage to the battery by overly depleting it.